Android Application WebAPI Development Training

Android application development
WebAPI course

Training Objectives
• Android WebAPI is required for application development

Acquire knowledge:
•
How to access WebAPI
- Asynchronous Graphical
- Reason to consider garbage collection
•
To analyze
- XML
- use the service
• Exercises, ask why you need to experience these issues.

This material is licensed under the Creative
Commons License BY-NC-SA 4.0.

2

Training Schedule
• Day 1
- Chapter 1 Introduction
- Chapter 2 WebAPI development knowledge
- Chapter 3 Preparing the Development Environment
- Chapter 4 Tutorial

• Day 2
- Chapter 5 use ListView
- Chapter 6 Exercises
- Chapter 7 Conclusion

3

Getting the necessary skills
Niatari attend a seminar, and found that minimum skills are required.
• Experience in Java language
• The exercises are actually programming in Java.
• The basic problem is understand Java language specification.

•

Experience in using Eclipse
- A drill in Eclipse where it is used to implement the program.
- Basic understanding of Eclipse (the problem of how to use Eclipse).

•

OESF official Android is already skilled or equivalent introductory course
application development.
• Android applications have basic skills
• Can easily create a multiple-screen applications


4

Chapter 1 Introduction
Chapter summary
•
•
•

Exercise the Development environment.
Practice Applications used.
About Exercise


6

1.1. Development
Development Description
• the following development tools is for this training.
• Training tools in development machine has already been
built
• Tools are included with the SDK path through the
environment variable
Software

Version

Integrated development
environment

Eclipse 3.5 (Galileo)

Java SDK

JDK 6 Update 21

Android SDK

2.1

Android Plug-in

Android Development Tools (ADT) Ver.0.9.9


7

1.2. About Exercise
Overview

• Eclipse Workspace: specified by
C:android_trainingdevtoolseclipseworkspace
• Emulator: emulator used in practice, unless
otherwise specified in particular, is WVGA-normalhdpi
• SDK path: has become
C:android_trainingtoolsandroid-sdk-windows


8

1.3. The application for exercise
•
•
•
•
•
•

Exercise, create a video download application.
Features Video Downloader
HTTP communication with WebAPI
Treatment works in the background
ListView applied technology
Parsing XML


9

1.4. Application for exercise (2)
• Video Downloader Screen and Features Overview
Function Name
Thumbnail

Thumbnail

Features Overview
• To view the video's thumbnail graphic

Title

• To view the attached video title

Description

• To view the video description

Title

Description


10

1.5. About Exercise
Explicit Intent
with screen
transitions

Connect to
WebAPI

Get the results from the
WebAPI server
Internet

SD Card

SD Card to store
videos
Enter your search
terms, press
"Search" button

Click to download the
video line

Parse the XML
Processing

Customize List

Click to play
the line

Use Download
Service


11

2. WebAPI development
knowledge

Chapter 2 - Overview
– What is WebAPI?
– The need for asynchronous display
– Reason to consider a garbage collection
– DOM, SAX, XMLPullParser

– Use of services

13

2.1. What is WebAPI?
•

Web Application Programming Interface
of the application program on the Web.

•

Basically, to use the SOAP or REST,
XML is used to exchange data.

•

As a typical thing, Yahoo API, Google
API, Youtube API … etc
Get / Post send

Sent in XML


14

2.2. The need for asynchronous display
•

•

If it takes longer to process what on-screen, then the screen is not enough to
display,
As a result, users would feel the stress.

•
•

So the process can be divided to view the text and images separately.
Text-only displayed first, later, image displayed.

•

Can relieve some stress for the user.


15

2.3. reason to consider GC
• Without considering the garbage collection (GC), less
memory available for Android.
• To make the program stops as soon as the Full GC occurs.
•

Full GC occurs and, in order to maintain consistency, all
threads will be stopped.

• After user program (user), GC treatment starts, because
nothing will be waiting.
Java VM

This material Full GC occurs
Principle of is licensed under the Creative

16

2.4. DOM, SAX, and XMLPullParser (1)
DOM (tree type)
• DOM as a tree with the heap, when parsing XML to hold the entire
contents of memory, after parsing any element that can be accessed
at any time.
• To keep everything in memory, it consumes more memory,
• Mobile devices that run Android have a problem.
• A small XML DOM document can be used to be implemented easily.
Okay Oso

DOM

Large memory consumption

17

SAX (event-driven)
• Parser to parse Application that calls the image.
• Iki XML document read from the beginning, And hit the start
and end tags, etc…, to call the determined application
callback routine.
• Control DOM By the application can not load the XML document.
•
•

Memory consumption is less than the DOM.
Er is
Android is the conventional method of using the SAX, onsoooo ♪
SAX
there are ways to use a wrapper.
My more

！！！！！

・・・ easy to use mon

SAX
DOM


18

XMLPullParser（ Pull Type ）
•

StAX JAVA by what shall have the same functionality. Android will
have the same function that StAX does not support.

• XMLPullParser are provided.
• StAX as an XML document read from the head of the load
• Performed by the application control information from the parser
as needed
• Can be obtained.
•

To make an application from the control, early in the parsing It can
be stopped, it takes a lot of time parsing
• Can be reduced.

19

Summary
ＤＯＭ

ＳＡＸ

XML
PullParser

Parser
Nature

Tree structure

Event-driven
(no control)

Event-driven
(controllable)

Access
to the elements

Random

Sequential

Sequential

Get element

The DOM tree
Access

Callback
Routine

When iterated
Get

Exporting XML

Possible

Impossible

Possible

Memory consumption

More

The least

Low

Ease of handling

Easy

Difficult

Easy


20

2.5. far from being used for service
• In the resident program, services are put in word.
• As a recipe, Web services are very similar. (WSDL, AIDL)
• The biggest difference between threads and services that they are running
even after exiting the Activity.
• The service can be remain started.
• In addition, Activity can also access the service restarts.
• Is used primarily in music players, GPS log information and timers.
Commonly use time-consuming process.

Thread


Service

21

3. Preparing the Development
Environment

3.1. Setting up Development Environment
• Install the following development tools.

Software

Version

Integrated development
environment

Eclipse 3.5 Galileo

Java SDK

Java SDK 1.6.x

Android SDK

2.1

Android Plug-In

Android Development Tools (ADT)


23

3.1. Setting up Development Environment (1)
•Install Android SDK
1. Launch Windows Explorer from the Start menu, Open C: android_training devtools .
2. Right-click the android-sdk_r **- windows.zip file, Expand All selected.
3. Deployment wizard steps along the C: android_training android_sdk deployed to ensure
that organized as the right figure.


24

•Set Environment Variables
1. Select Control Panel from Start menu ,Double click[System].
2. Click the Advanced tab in The System Properties, Click Environment Variables button.


25

3. At Environment Variables window, click [Path], from Environment Variables System and then
Edit button.

4. Add c: android_trainingtoolsandroid_sdktools. at the beginning of the Edit System
Variable window Variable value


26

•5. In Edit System Variable window, click [OK] button.
•6. In Environment Variables window, click [OK] button.
•7. To ensure that the environment changes is reflected.
7-1. Start Menu->All Programs -> Accessories ->command Prompt, and then start a command prompt.


27

•7-2. Run the following command from the command prompt: set [<sp>] | <sp>
find <sp> "android“
•To ensure that you receive the Path settings.
•※ <sp> · · · meaning of space


28

• Android Development Tools (ADT) Installation
1. Start Eclipse.
2. Click Help in Eclipse menu, select Install New Software.


29

•3. In the Install window, click Add,
•4. Adding a site to the location of the window
–http://dl-ssl.google.com/android/eclipse/
–Enter [OK] button.
※ The name of any location.


30

5. In Installation Details window, check Developer Tools, Press [Install] button.
6. Then click Next button in the install window.


31

7. In Install window, check [I accept the terms of use], click
[Finish] button to start the installation.
•If the warning dialog for unsigned software installation appears,
continue clicking [OK].
8. Installation is complete, click [Yes] when you see the
Software Updates message, restart Eclipse
Progress is being installed

Software Installation warning dialog
32
unsigned

•9. After restarting Eclipse, In the Development Tools
toolbar make sure that the Android button has been
added.


33

• Installing the Android Platform

1. Eclipse menu: from [Window] select [Android SDK and AVD Manager].


34


2.

from a tree on the left select [Available Packages], Tick [SDK
Platform Android 2.1, API 7 revision 2], click [Install Selected].


35


3. Tick [Accept All], and then click Install.

If you see a dialog box that mean " Do you want to Update?" click
"yes"
4.


36

5.

When you see the screen shown at right, Click "close" to Close Window

6. Check below C:android_trainingandroid_sdkplatforms, "android-7" to
make sure that the folders are made


37


7. Restart eclipse.


38

• Set the Eclipse-ADT to recognize the Android SDK.
1. From Eclipse [Window] menu, select [Preferences].


39

•2. In Preferences window select
[Android].
•An error message appears, close the
message window:
–Set error message at the top of the
window
–Make sure to disappear, click [OK] button.

•

Select SDK location C:devlopandroidsdk-windows and press enter, then click
[OK].


40

How to Display Task
From the "Window" menu ,
select "Tasks" on
"ShowView"

In "Tasks" select the Eclipse
task list that appears at
the end


41

• Get more training for the skeleton project
- Each exercise includes a project to create a skeleton file
• Please proceed to import the project to study the skeleton project.

From "File" select
"Import“, import dialog
is displayed

From "General" select
"Existing Projects into
Workspace" press"Next"


Select a file for each
skeleton practice. Please
press "Finish"

42

4.1. Creating a Simple Application
• Create a simple screen transitions application.


44

4.1. Creating a Simple Application (1)
•Application Summary
<Project Settings>
Items

Setting

Project name

ActivitySample

Build Target

2.1

Application name

ActivitySample

Package name

jp.oesf.activitysample

Create Activity

MainActivity

<Additional setting Activity>
Items

Setting

Class Activity

SubActivity


45

•Application Summary
＜main.xml＞
View

Id (@+id / id名)

layout_width

Text

On click

TextView

text_title

wrap_content

@string/main_activity

Not Set

EditText

edit_message

fill_parent

Not Set

Not Set

Button

button_sub

fill_parent

@string/go_to_subActivity

onClickSubButton

Button

Button_end

fill_parent

@string/main_end

onClickEndButton

＜sub.xml＞
View

Id (@+id / id名)

layout_width

Text

On click

TextView

text_title

wrap_content

@string/sub_activity

Not Set

TextView

text_message

wrap_content

Not Set

Not Set

Button

button_main

fill_parent

@string/go_to_mainActi
vity

onClickMainButton


46

•Classes: to create class MainActivity and SubActivity.
The Main Screen
Passing Data to Sub-screen
Intent to execute a move to create a sub-screen class.
Intent intent = new Intent(this, SubActivity.class);
EditText editText = (EditText)findViewById(R.id.edit_message);

Intent#putExtra using data stored in Intent
String message = editText.getText().toString();
intent.putExtra("TEXT", message);
startActivity(intent);

The Sub-screen
Data obtained from the main screen.
Intent to create and run a class move to the main screen.
Intent intent = getIntent();
String message = intent.getStringExtra("TEXT");
TextView textView = (TextView)findViewById(R.id.text_message);
textView.setText(message);
Back to the main screen.
finish();

47

•Answer
＜MainActivity.java＞
public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void onClickSubButton(View v){
Intent intent = new Intent(this, SubActivity.class);
EditText editText = (EditText)findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra("TEXT", message);
startActivity(intent);
}
public void onClickEndButton(View v){
finish();
}
}


48

Answer
＜SubActivity.java＞
public class SubActivity extends Activity {
@Override
setContentView(R.layout.sub);
Intent intent = getIntent();
String message = intent.getStringExtra("TEXT");
TextView textView = (TextView)findViewById(R.id.text_message);
textView.setText(message);
}
public void onClickSubButton(View v){
finish();
}
}


49

Answer

＜ main.xml ＞

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/text_title"
android:text="@string/main_activity">
</TextView>
<EditText
android:id="@+id/edit_message"
android:layout_width="fill_parent">
</EditText>
<Button
android:text="@string/go_to_subActivity"
android:id="@+id/button_sub"
android:onClick="onClickSubButton">
</Button>
<Button
android:text="@string/end" android:id="@+id/button_end"
android:onClick="onClickEndButton">
</Button>
</LinearLayout>


50

Answer

＜ sub.xml ＞

<TextView
android:text="@string/sub_activity">
</TextView>
<TextView
android:id="@+id/text_message">
</TextView>
<Button
android:text="@string/go_to_mainActivity"
android:id="@+id/button_main"
android:onClick="onClickSubButton">
</Button>
</LinearLayout>

51

Answer
＜ strings.xml ＞

<resources>
<string name="hello">Hello World, MainActivity!</string>
<string name="app_name">ActivitySample</string>
<string name="main_activity">MainActivity</string>
<string name="go_to_subActivity">Go to SubActivity</string>
<string name="main_end">End</string>
<string name="sub_activity">SubActivity</string>
<string name="go_to_mainActivity">Go to MainActivity</string>
<string name="sub_end">End</string>
</resources>


52

Answer
＜ AndroidManifest.xml ＞
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="jp.oesf.activitysample"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SubActivity"
</activity>
</application>
<uses-sdk android:minSdkVersion="7" />

</manifest>

53

5 Chapter Summary
•
•
•

Using ListView
Sample application using ListView
Create a customized list view


55

5 Chapter Summary
• <Listview Overview >
• ListView view group is to display data in a list format.
• ListView is also possible to change the layout of the item.
Displayed in list
format
You can also change
the layout


56

5 Chapter Summary
<Adapterno Overview >
View data with a role Adapter stitching.
View Adapter will be displayed from the job of assembling the data.
View the data and
the role of tie

Adapter

Data

Assemble View Show

57

5 Chapter Summary
View assembly mechanism
Adapter is responsible for coordination of data and views, and the role of assembling views
data to be displayed.
Array and List (ArrayList, etc.) are the elements of View to determine whether to display
the structure getView method or not.
getView method
getView method will be called when new data appears.
ListView, then scroll to the screen, when new data appears from off screen.
Nature, because it is called many times at the scroll, getView method have inappropriate logic,
and cause discomfort to scroll the screen, a negative impact on performance.

Return value

Method Name

View

getView (int position, View contentView, ViewGroup parent)


58

5.2. Creating a Sample Application
•

<Overview of the sample projects>

Items

Setting

Project name

ListSample

Build Target

2.1

Application name

ListSample

Package name

jp.oesf.listsample

Create Activity

ListSample

Min SDK Version

7


59

•

1. Define the layout
1-1in eclipse, Create res/layout/list.xml in
res/layout.
–

right-click [More] –New, in the [Android]
select [Android XML File] and click [Next]


60

–

enter the file name list.xml and click Finish.


61

•

1-3 ListView Paste
List.xml is created, select Layout tab,
Select ListView from Layouts, Drag & Drop it


62

•

(2) The Outline is added to ListView01

•

(3) Change the properties of the id field.
If you are using ListActivity, make sure you have
this id [@ android:id/list]


63

•
•
•
•

Create layout row by
create List_row.xml.
Select the XML file
folder layout,
Right-click
"New"→"Other"→
select " Android XML
File "
To add TextView to
the layout
Select, Create TextView

64

1-4 creating row layout by List_row.xml
•

In the Properties window, change the Id of the TextView
to “text_title”

•

Change [Layout width] to the “fill_parent”

•

in [Text appearance] Property Type:
“? android: attr / textAppearanceLarge”

Property changes

Changed value

id

@+id/title_text

Layout width

@+id/fill_parent

Text appearance

?android:attr/textAppearanceLarge

65

•

2. Use of ListActivity
–
–
–

2-1 ListSample class that inherits from the ListActivity
2-2 setContentView arguments to change R.layout.list
2-3 Set ArrayAdapter
The layout of the row by TextView
Resource Id

<Arrayadapternokonsutorakuta>
ArrayAdapter<T>( Context context, int
textViewResourceId, T[] objects)

Wish list
Array of items

Name

Type

Mean

The first argument(context)

Context

Specifies the object class.

Second
argument(textViewResourceId)

int

TextView resource ID is specified.

The third argument(objects)

T[]

Specify the data array of objects show


66

• ＜ ListSample.java＞
public class ListSample extends ListActivity{
static public final String mItems [] = {"Shiba", "dog"Hokkaido, "Kai Dog", "Kishu dog, "
"tosa”"Dog Shikoku", "Akita", "dog"Jomon, "Ryukyu dog", "dog Kawakami, " "Dog Satsuma",
"Mino Shiba”"Sanin Shiba", "bush beans"};
@Override
setContentView(R.layout.list);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
R.layout.list_item, mItems);
setListAdapter(adapter);
}

}


67

•

＜

list_row.xml＞

<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:textAppearance="?android:attr/textAppearanceMedium">
</TextView>


68

• 3. result

Automatic scrolling


69

5.3. Customizing the list view
•Create rich user interfaces using little ListView.
•<target figure ( list of three items: titles, description and
thumbnails)>
Thumbnail
Title

Description


70

•Screen structure
- to be able to see the three elements, "thumbnail", "title“ and "description" in one
line,
1. editing list_row.xml layout
- thumbnails => ImageView
- title, description => TextView
to make the full use of the above sequence use the following LinearLayout :
View

@+Id

ImageView

@+Id/image_thumbnail

LinearLayout

@+Id/LinearLayout01

TextView

@+Id/text_title

TextView

@+Id/text_summary


71

<Linearlayout(Outside)>: No change. Remain as created by default.
＜LinearLayout（ Inside ）＞
Items

Value

id

@+id/LinearLayout01

layout_height

wrap_content

layout width

wrap_content

orientation

vertical

＜ImageView＞
Items

Value

id

@+id/image_thumbnail

layout_height

wrap_content

layout width

wrap_content


72

＜TextView（ Title ）＞
Items

Value

id

@+id/text_title

layout_height

wrap_content

layout width

wrap_content

textAppearance

?android:attr/textAppearanceMedium

＜ TextView（ More ）＞
Items

Value

id

@+id/text_summary

layout_height

wrap_content

layout width

wrap_content

textAppearance

?android:attr/textAppearanceSmall


73

Create a custom Adapter class
<Procedure>

1 RowModel: To create a data class
•Members → to hold "title, description,
thumbnail“.
2 ArrayAdapter to create a class that inherits
from TableAdapter
•override getView () to implement the necessary
processing
–The null check is required for convertView
–Set the value of each item to view
This to setListAdapter
4 change Adapter material is licensed under the Creative

74

•Create a custom Adapter class (1)
1. Create RowModel
1. Create "Src" folder under the package [jp.oesf.listsample.model]
2. Create a RowModel class.
3. define a member variable to hold "title, description, thumbnail“ .

4. Define Getter and Setter for each variable.
public class RowModel {
private String title;
private Drawable thumbnailImage;
private String summary;
"getter setter for each variable listed"

}


75

Create a custom Adapter class (2)

2. ArrayAdapter to create a class that inherits from TableAdapter
1. ListSample.java the generic file to create a TableAdapter that extend TableAdapter class that
specifies RowModel

2. creates an overridden GetView method
3. View Item generation and that time taken to set the check null.
class TableAdapter extends ArrayAdapter<RowModel>{
public TableAdapter(Context context) {
super(context, R.layout.list_row);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;

RowModel item = getItem(position);
if(row == null){
LayoutInflater inflater = getLayoutInflater();

}

row = inflater.inflate(R.layout.list_row,under the Creative
This material is licensed null);

76

Create a custom Adapter class (2)

2. Create ArrayAdapter to extend TableAdapter classes, more
if( item != null){
// Image
ImageView imageView = (ImageView)row.findViewById(R.id.image_thumbnail);
if( imageView != null){
imageView.setImageDrawable(item.getThumbnailImage());
}
//Title
TextView textTitle = (TextView)row.findViewById(R.id.text_title);
if(textTitle != null){
textTitle.setText(item.getTitle());
}
// summary

TextView textSummary = (TextView)row.findViewById(R.id.text_summary);
if(textSummary != null){
textSummary.setText(item.getSummary());
}
}
return row;
}


77

create a custom Adapter class (3)

3. Adapter with a set of values

1. set SetListAdapter methods in the TableAdapter in onCreate ListSample
2. get the text array from the resource
TableAdapter adpter = new TableAdapter(this);
setListAdapter(adpter);
/ / RowModel Create
String titles[] = getResources().getStringArray(R.array.titles);
String summaries[] =
getResources().getStringArray(R.array.summaries);
Drawable image = getResources().getDrawable(R.drawable.icon);
int num = titles.length;


78

Adapter to create a custom class (3)

3. Adapter at a set of values

3. RowModel: set the acquired the sequence value
4. RowModel: set to the Adapter
for(int i = 0; i < num; i++){
RowModel row = new RowModel();
row.setTitle(titles[i]);
row.setSummary(summaries[i]);
row.setThumbnailImage(image);
adpter.add(row);
}
}


79

Tags on string-array
xml files that describe the data, you can retrieve data from the application of a string array.

Syntax

<resources>
<string-array name="string_array_name">
<item>text_string</item>
<item>text_string</item>
</string-array>
</resources>

string-array lists the defined name.
ID is used as a resource.
lists the data stored in the String-array.


80

•＜strings.xml＞
<resources>
<string name="app_name">ListSample</string>
<string-array name="titles">
<item> Shiba </ item>
<item> Hokkaidou dog </ item>
Kai Dog
<item> </ item>
<item> Kishu dog </ item>
tosa
<item> </ item>
<item> Shikoku dog </ item>
Akita <item> </ item>
<item> Jomon dog </ item>
<item> Ryukyu dog </ item>
Kawakami
<item> dog </ item>
Satsuma
<item> dog </ item>
<item> Mino Shiba </ item>
Sanin Shiba
<item> </ item>
<item> bush beans </ item>
</string-array>


81

•<String.xml(Continued)>
<string-array name="summaries">
<item> Japanese mind. Small dogs only dog in Japan. </ Item>
Ainu Dog <item> alias. Dogs and the sum of thinking and pure species and </ item>
Kakoi <item> 虎毛! Between medium and small size </ item>
Many white <item>. Feed the tail end of a book more often </ item>
闘犬 <item> Tosa. Bulldog and Mastiff dogs Great Dane was created and arranged </
item>
Canis lupus hodophilax <item> can be mistaken! </ Item>
<item> only large Japanese dog dog. "Matagi Akita" Matagi dog. Hachi! </ Item>
<item> indigenous Japanese dog </ item>
<item> to leave the old dog traits since the Jomon Period </ item>
Nagano <item> protected species </ item>
Takamori Saigo <item> dog </ item>
Dog <item> Mino, Hida both bush </ item>
Inaba base <item> dog. Feed the tail, forming the evening. Change shape as you keep
SHEPHERD E?! </ Item>
Shiba Inu Small <item> nickname. Preservation Society and the Japanese dog JKC in the
"bush beans" pedigree that does not exist </ item></string-array>
</resources>

•As a resource to get the code
// getting resource array data
String summaries[] = getResources().getStringArray(R.array.summaries);


82

•<result>


83

•＜RowModel.java＞
public class
private
private
private

RowModel {
String title;
Drawable thumbnailImage;
String summary;

public final String getTitle() {
return title;
}
public final void setTitle(String title) {
this.title = title;
}
public final Drawable getThumbnailImage() {
return thumbnailImage;
}
public final void setThumbnailImage(Drawable thumbnailImage) {
this.thumbnailImage = thumbnailImage;
}
public final String getSummary() {
return summary;
}
public final void setSummary(String summary) {
this.summary = summary;
}
}


84

•＜ ListSample.java＞
public class ListSample extends ListActivity {
@Override
TableAdapter adapter = new TableAdapter(this);
setListAdapter(adapter);
// add data
Drawable image = getResources().getDrawable(R.drawable.icon);
adapter.clear();
for(int i=0; i<num; i++){
row.setThumbnailImage(image);
adapter.add(row);
}
}
private class TableAdapter extends ArrayAdapter<RowModel> {
Activity context;
TableAdapter(final Activity context) {
super(context, R.layout.list_row); the Creative
This material is licensed under
this.context = context;
}

85

＜ ListSample.java＞
@Override
if (row == null) {
// new create
LayoutInflater inflater = context.getLayoutInflater();
row = inflater.inflate(R.layout.list_row, null);
}
// set disp
if (item != null) {
// Image
ImageView imageView = (ImageView) row
.findViewById(R.id.thumbnail_image);
if (imageView != null) {
}
// Title
TextView textTitle = (TextView) row.findViewById(R.id.title_text);
if (textTitle != null) {
}
// summary
TextView textSummary = (TextView)row.findViewById(R.id.summary_text);
if(textSummary!=null){
}
}
return row;
}
}


86

•＜list_row.xml＞
android:layout_width="wrap_content" android:layout_height="wrap_content">
<ImageView android:layout_width="wrap_content"
android:layout_height="wrap_content" android:id="@+id/image_thumbnail"></ImageView>
<LinearLayout
android:id="@+id/LinearLayout01"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:textAppearance="?android:attr/textAppearanceMedium">
</TextView>
<TextView
android:id="@+id/text_summary"
android:textAppearance="?android:attr/textAppearanceSmall">
</TextView>
</LinearLayout>
</LinearLayout>


87

Chapter 6 Overview
Create a Video Downloader, you will learn the following techniques:
• HTTP communication with WebAPI
•

Parsing XML

•

Using Traceview

•

Screen with an asynchronous

•

Service Creation


89

6.1. display of asynchronous (preparation)
•
•
•
•

Eclipse project to incorporate training for skeleton
Locations
Answer folder android_training_webapi skeleton_project
In this case, capture "MediaDownloaderSkeleton01"

•
•
•

How to Get?
Start the Eclipse "File" menu, select "Import", "Import" dialog is shown
"Import" dialog, from "General” select "Existing Projects into Workspace“, press "Next" button to capture
the root directory of the project skeleton
check "Copy projects into workspace".

•


90

6.1. display of asynchronous (1)
•Exercise: To experience the state of synchronization, Try to run
first.


91

•When asynchronously
•Downloading images is a time consuming process, to be shown later,
•You can reduce the stress of the user.

Now loading
Icon appears

Gradually icon
Appear


Complete

92

•Using AsyncTask
AsyncTask subclass that inherits the class
AsyncTask subclass of the run-time arguments (Params), Progress units (Progress),
Processing result needs to be handled by specifying the (Result) type.

Generic

Description

Params

doInBackground Method Arguments

Progress

onProgressUpdate Method Arguments

Result

onPostExecute Method Arguments
doInBackground that must match the method return values


93

• Define AsyncTask

Specify the type corresponding to
the arguments of each method

class MyAsyncTask extends AsyncTask<Params, Progress, Result>{
@Override
protected Result doInBackground(Params... params) {
return null;
}

The doInBackground
Override Required

}

Return value

Method Name

Description

abstract Result

doInBackground(Params... params)

Background execution

void

onPostExecute(Result result)

Upon completion of the process run in the background

void

onPreExecute()

Previous operation to run in the background

void

onProgressUpdate(Progress... values)

Progress Update for Background Processing

void

onCancelled()

Cancel Background Processing

※ doInBackground onProgressUpdate for varargs and, even when passing non array in param [0] should be referenced

94

Execute AsyncTask
• General way to create and execute an instance of subclass of AsyncTask,
AsyncTask can be canceled during the execution
/ / get an instance of AsyncTask
MyAsyncTask task = new MyAsyncTask ();
/ / execute AsyncTask
task.execute ("MyAsyncTask execute");

• execute AsyncTask at instantiation of a subclass
•Used if there is no need to cancel asynchronous implementation.
•does not hold an instance can not be canceled if AsyncTask is running

/ / AsyncTask to run when the instantiation
new MyAsyncTask (). execute ("args as doInBackground");


95

Example
AsyncTask counting program for 10 seconds.
Indicator to display the count in the top right.

Count starts after start
Indicator Displays

Counting


End after ten seconds
Indicator disappears

96

Sample Program
public class AsyncSample extends Activity {
private TextView text;
@Override
/ / display the title bar indicators
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
this.text = (TextView)findViewById(R.id.TextView01);
this.text.setText("" + 0);
/ / AsyncTask run
new MyAsyncTask().execute("args as doInBackground");
}


97

Sample Program
class MyAsyncTask extends AsyncTask<String, Integer, Boolean>{
@Override
protected void onPreExecute() {
/ / onPreExecute Handler uses the UI can be changed without
/ / Display indicators
setProgressBarIndeterminateVisibility(true);
}
@Override
protected Boolean doInBackground(String... params) {
Log.v("MyAsyncTask", "param:" + params[0]);
for( int i = 0; i <= 10; i++){
try {
/ / progress update notification
publishProgress(i);
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
return false;
}
}
return true;
}

98

Sample Program

@Override
protected void onPostExecute(Boolean result) {
/ / onPostExecute Handler uses the UI can be changed without
if( result ){
text.setText(" Complete ");
}else{
text.setText(" Failure ");
}
// To hide the indicator
setProgressBarIndeterminateVisibility(false);
}
@Override
protected void onProgressUpdate(Integer... values) {
// In onProgressUpdate UI Handler can be modified without
text.setText("" + values[0]);
}
}
}


99

• Creating a Sample Program
AsyncTask image acquisition process is performed by updating the screen at the time you get.
Indicator to display on the right of the screen

Completed chart

Now loading
Icon appears

Gradually icon
Appear


Complete
100

Sample Program Description
SampleList.java

// TODO No.01 in the title bar to display the indicator
adpter = new TableAdapter(this);
// Creating RowModel
// Get a text array from the resource
Drawable loadingImage = getResources().getDrawable(R.drawable.ic_contact_picture);
RowModel[] models = new RowModel[num];
// RowModel created for each single line
// Into array
for(int i = 0; i < num; i++){
row.setThumbnailImage(loadingImage);
adpter.add(row);
models[i] = row;
}
// TODO No.08 asynchronous call
}

101

SampleList.java

//Set each data element in the list to display each line
@Override
if(row == null){
// Creating View
LayoutInflater inflater = getLayoutInflater();
row = inflater.inflate(R.layout.list_row_rich, null);
}
if( item != null){
// Image
ImageView imageView = (ImageView)row.findViewById(R.id.image_thumbnail);


102

SampleList.java

if( imageView != null){
}
//Title
TextView textTitle = (TextView)row.findViewById(R.id.text_title);
if(textTitle != null){
}
// summary
TextView textSummary = (TextView)row.findViewById(R.id.text_summary);
if(textSummary != null){
}
}
return row;
}
}


103

6.1. display of asynchronous ()
Asynchronous processing of image acquisition
Process The image acquisition asynchronously
INNER ListSample class "LoadImageTask" is defined. Implement the following actions:
<Procedure>

1.

To implement the onPreExecute methods .
1.
Show Injiketadaiarogu process
2.
To implement the methods doInBackground
1.
RowModel arguments one by one to get data from an array to set the
thumbnail.
※ListSample#getImage method to get the thumbnail image
1.

Once thumbnail setup is complete, display ListView one at a time
※ using onProgressUpdate # onProgressUpdate which is callback
method for AsyncTask # publishProgress .
3.
to implement the onProgressUpdate method.
1.
Renewal notices a TableAdapter
※ Adapter #. NotifyDataSetChanged Adapter Using methods that are bound
to redraw View
4.
to implement the methods onPostExecute
This material
1.
To hide Injiketadaiarogu is licensed under the Creative
104

Method Implementation
Methods onPreExecute
protected void onPreExecute() {
// Indicator Display
setProgressBarIndeterminateVisibility(true);
}

Methods onProgressUpdate
protected void onProgressUpdate(Void... values) {
/ / change notification data
adpter.notifyDataSetChanged();
}

Methods onPostExecute
protected void onPostExecute(Void result) {
// To hide the indicator
setProgressBarIndeterminateVisibility(false);
}

105

Methods doInBackground
protected Void doInBackground(RowModel... arg0) {
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_BACKGROUND);
// Read data from the arguments one by one, RowModel setting of Drawable
for(RowModel rowModel : arg0){
if(isCancelled()){
Log.v("ListSample", "LoadImageTask#doInBackground() canceled.");
break;
}
// Get thumbnail
rowModel.setThumbnailImage(getImage());
// Update Notification
publishProgress((Void)null);
}
return null;
}


106

ListSample.java
// Indicator to display the title bar
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
adpter = new TableAdapter(this);
- almost / / asynchronous call
new LoadImageTask().execute(models);
}


107

6.1. Web services to connect
• HTTP communication with WebAPI, For HTTP communication
•
•
•
•
•
•
•
•
•
•
•
•

DefaultHttpClient: to communicate HTTP with the class.
Set the request method.
GET method: use HttpGet class.
POST method: use HttpPost class.
Issue requests to the specified URL.
Pass HttpGet DefaultHttpClient # execute method arguments.
To check the status response.
To get the status code return HttpResponse class.
※ The HttpStatus status code constants are available in the class.
Status Code: 200 HttpStatus.SC_OK are defined.
Toridasu the necessary information from the response data.
Return (HttpResponse) from HttpEntity (HTTP object for incoming and
outgoing) can be obtained.


108

• Sample Code
// Destination URL
String url = "http://www.oesf.jp/";
// Object Creation DefaultHttpClient
DefaultHttpClient client = new DefaultHttpClient();
// GET request to the connection object creation method
HttpGet get = new HttpGet(url);
try {
// To get a response to a request issued
HttpResponse res = client.execute(get);
// Check the status code
if(res.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
// Response to obtain information
HttpEntity entity = res.getEntity();
}
} catch (Exception e) {
}


109

• Creating a Sample Program
Communicates HTTP GET method, the program checks the status code.
Completed chart

Click
Logs


110

6.1. Creating a sample program (Overview)
Create a sample HTTP communication program
Items

Setting

Project name

HttpSample

Build Target

2.1

Application name

HttpSample

Package name

jp.oesf.httpsample

Create Activity

HttpSample


111

6.1. Creating a sample program (provision)
•

Eclipse project to incorporate training for skeleton
Location:
Folder where you unzipped "HttpSample_skeleton01.zip"
android_training_webapiChapter 6 HTTP Makoto Tooru

From "File" select "Import”
and "Import" dialog is
displayed

In "General" select "Existing
Projects into
Workspace“ then
Press"Next"


Select the Zip file and press
"Finish"

112

6.1. Web services to connect to (1)
Creating a Sample Program
<Procedure>
Fixed string.xml
"HTTP communication " to add the string
Fixed main.xml
"HTTP Communication " to add button
Add an HTTP communication processing class Activity
When the button is pressed for HTTP connections.
Destination "http://www.oesf.jp/"
To ensure that the status code 200
To print “OK” in Log status
Fixed AndroidManifest.xml
Add internet communication Permissions

113

How to Display Task

On the menu “Window“,
from ”ShowView”
select “Tasks”

At the bottom of "Tasks" select
the Eclipse task list.


114

Modify a resource file
string.xml property tables
name

String

connect_http

HTTP communication

app_name

HttpSample

main.xml property tables
Items

Value

View

Button

@+id / id name

button_connect_http

layout_width

fill_parent

Text

connect_http

On click

onClickButton


115

Activity class to add the HTTP communication processing

1. implementation of the onClickButton method
* Handling HTTP GET method to additional communicate
Generating DefaultHttpClient object
HttpGet to create objects.
Argument to specify url: "http://www.oesf.jp/"
To get a response to a request issued
DefaultHttpClient # execute method to execute, HttpResponse objects to be returned
Check the status code
HttpResponse # getStatusLine () # getStatusCode () to check the status code

2. If the log output status output log 200: Log.v (TAG, "status ok");


116

Fixed AndroidManifest.xml
1. Add internet communication Permissions
AndroidManifest.xml file
Append permission to allow Internet access.

</activity>
</application>
<! - Add internet communication allowed permissions ->
<uses-permission
android:name="android.permission.INTERNET">
</uses-permission>
</manifest>


117

The answer to create a sample program
string.xml
<resources>
<! - HTTP communication "defines a string ->
<string name="connect_http"> HTTP communication </string>
<string name="app_name">HttpSample</string>
</resources>


118

main.xml

<! - Button Add ->
<Button
android:id="@+id/button_connect_http"
android:text="@string/connect_http"
android:onClick="onClickButton">
</Button>
</LinearLayout>


119

HttpSample.java
public class HttpSample extends Activity {
private static final String TAG = "HttpClientSample";
// Destination URL
private static final String URL = "http://www.oesf.jp/";
@Override
}
public void onClickButton(View v) {
// No.01 DefaultHttpClient object generating
// No.02 GET request to the connection object generating method
HttpGet get = new HttpGet(URL);


120

HttpSample.java(2)
try {
// No.03 to get a response to a requested issue
// To check the status code No.04
if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
// No.05 log output
Log.v(TAG, "status ok");
}
Log.e(TAG, Log.getStackTraceString(e));
}
}


121

AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="jp.oesf.httpsample"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".HttpSample"
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<! - Add internet communication allowed permissions ->
<uses-permission
android:name="android.permission.INTERNET">
</uses-permission>
</manifest>

122

The sample program creates two answers
The sample program was created to add functionality to display the content.
Completed chart

Click


123

Get response data
1.

Gets the HttpResponse HttpEntity.
Get the content from the InputStream HttpEntity use.
HttpEntity # getContent method can get the InputStream.
OutputStream using the read data from InputStream.
To convert imported data to a string.
Stream Close
InputStream in = null;
ByteArrayOutputStream out = null;
try {
// InputStream retrieve content by using the
in = res.getEntity().getContent();
out = new ByteArrayOutputStream();
// HTTP response data is read
byte[] line = new byte[1024];
int size = 0;
while (true) {
size = in.read(line);
if (size <= 0) {
break;
}
out.write(line, 0, size);
}
// To convert the data into a string
String http = new
String(out.toByteArray());
} catch licensed under
This material is (Exception e) { the Creative

124

The sample program creates two answers
<Procedure>
Fixed main.xml
TextView content for display of additional data
Activity in response to a class data acquisition process
getContents method implementation
Get the InputStream from the response
Read the data content
Returns data converted to a string
Data obtained on the screen
Properties main.xml
View

@+ id / id name

layout_width

Text

On click

Button

button_connect_http

fill_parent

connect_http

onClickButton

TextView

text_content

wrap_content

No

No


125

Answer
mainxml
<! - Button Add ->
<Button
android:id="@+id/button_connect_http"
android:text="@string/connect_http" android:layout_width="fill_parent"
android:onClick="onClickButton">
</Button>
<! - TextView Add ->
<TextView
android:layout_width=“wrap_content”
android:id="@+id/text_content">
</TextView>
</LinearLayout>

126

The two answers to create a sample program
HttpSample.java

public void onClickButton(View v) {
HttpGet get = new HttpGet(URL);
try {
if (res.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
Log.v(TAG, "status ok");
// Comment out the following release
String content = getContents(res);
// TextView display content data obtained
TextView text = (TextView)findViewById(R.id.text_content);
text.setText(content);
}
}
}


127

HttpSample.java(2)

private String getContents(HttpResponse res) {
ByteArrayOutputStream out = null;
byte[] line = new byte[1024];
String data = null;
int size = 0;

try {
// Get the InputStream from the response
in = res.getEntity().getContent();
out = new ByteArrayOutputStream();
// HTTP response data is read
while (true) {
size = in.read(line);
if (size <= 0) {
break;
}
out.write(line, 0, size);
}
// Convert byte array to a string
data = new String(out.toByteArray());


128

HttpSample.java(3)

}finally{
try {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
}
}
return data;
}


129

6.2. XML is analyzed (DOM)
•

What is XML?

One of the markup language for describing the structure and meaning of the data.
Markup language "tags" in the sentence structure and meaning of information in a
particular string, will called the embedded language and decoration.
Users can specify their own tags
Type

Contents

Description

Tags

<id> ～ </id>

"<"and ">" tag of the part enclosed by a
start tag and end tag

Attribute (attribute)

<thumbnail url “ ～ ”>

Be used to add additional information
to the tag

Value (Value)

<title> ～ </title>
<thumbnail url =“ ～ ”>

Son of a string enclosed with tags, if
the attribute value specified by "="

Namespace (namespace)

<feed xmlns:media = “ ～ ”>
<media:group/>
</feed>

To use to resolve conflicts by the same
tag name, namespace URI must be
unique


130

6.2. XML parsing to create a mechanism to
(prepare)
6.1 Please refer to the HTTP traffic. Capture to create a sample program (coming
soon)
•How to Get
•Eclipse project to incorporate training for skeleton
Locations
Capture answer folder android_training_webapi Chapter 6 XML
parsing "XmlSample_skeleton01.zip ~ XmlSample_skeleton03.zip"


131

6.2. XML to parse
•

Skeleton Program

XML parsing exercises to create a sample using DOM, SAX, XMLPullparser.
Skeleton project has been implemented using the following functions:
XmlSample_skeleton01: parsing Unimplemented
XmlSample_skeleton02: DOM parsing process has been implemented
XmlSample_skeleton03: DOM and SAX parsing process is implemented
Each project is described in the task of implementing the exercise.
※ For the confirmation of the task, Please refer to the "TODO: HTTP Makoto Tooru
XXX "


132

6.2. XML to parse
•

Skeleton Program
Resource definition information
XmlSample_skeleton01 to XmlSample_skeleton03
Resources are defined in the following contents:

View

id (@ + id / id name)

Text(@+string )

On click

LinearLayout

LinearLayout01

LinearLayout

LinearLayout02

Button

button_dom

@string/dom

onClickDOMButton

Button

button_sax

@string/sax

onClickSAXButton

Button

button_xmlpullpaser

@string/xml_pullpaser

onClickXMLPullpaserButton

TextView

text_result

No

No


133

6.2. XML to parse
•

Parsing XML

Use the following XML document, DOM · SAX · XMLPullparser in XML Analysis

<sample.xml> ※ sample.xml The following assets are stored in folders
<?xml version="1.0" encoding="UTF-8"?>
<feed>
<entry>
<id>hPzNl6NKAG0</id>
<group>
<description> Everything is included for better sliding. (Just playing only) </description>
<thumbnail url="image/cat.jpg"></thumbnail>
<title> Training a cat. </title>
</group>
</entry>
</feed>


134

6.2. XML to create a mechanism to analyze (2)
•From an XML document to get and analyze the
following elements
The acquired data set RowModel

Tags

Attributes

Get value

id

No

hPzNl6NKAG0

title

No

Training a cat.

description

No

Everything is included for better sliding.

thumbnail

url

image/cat.jpg


135

6.2. Parse XML
•

About RowModel

•Data were analyzed by the XML held in RowModel
•Xml file analysis, data obtained by video downloader
•This is a simplified information
•The following RowModel jp.oesf.xmldomsample.model
•Is defined in the file "RowModel.java".
•XML data document that defines the following member variable holds:
Variable

Get Data

id

<id>

title

<title>

Summary

<description>

thumbnailImageURL

<thumbnail url = "Get data">


136

6.2. XML to parse
•DOM (tree type)
• XML DOM with the contents of the heap as a tree.
• When parsing XML to hold the entire contents of memory after parsing, any
element can be accessed at any time.
• To keep everything in memory, it consumes more memory,
• Mobile devices that run Android have a problem.
• A small XML DOM document can be used to easily implement.
Okay Oso

DOM

Large memory consumption

137

Analysis of the XML DOM tree
Element

<feed>

Description
Tags

Attributes

<entry>
<id>
Video ID

Value

<group>
<description>

<thumbnail>

<title>

url
Video Description

Thumbnail Image
The URL


Title
138

•
Parsing XML with DOM
<Procedure>
•
Document object to retrieve XML data
•
DocumentBuilderFactory to create objects
•
Creates a DOM parser
•
Building parse XML into DOM tree
•

Get the root element of XML data

•

Follows the DOM tree to get the desired node

•

To obtain the data held by the nodes (tags and text
data)

139

The following sample XML document parsing
<root>
<node1>Node Value</node1>
</root>

※ The new line is not actually


140

Sample Code
try {
//Generate Dokyumentobirudafakutori
DocumentBuilderFactory dbfactory = DocumentBuilderFactory
.newInstance();
// Generate Dokyumentobiruda
DocumentBuilder builder = dbfactory.newDocumentBuilder();
// get a stream of xml file
in = getAssets().open("samplea.xml");
// To retrieve and parse the Document Object
Document doc = builder.parse(in);
// Gets the root element (tag name: root)
Element root = doc.getDocumentElement();
// Get <node1>
NodeList entryList = root.getElementsByTagName("node1");
// First get <node1>
Element node1Element = (Element) entryList.item(0);
// Get the value of <node1>
String nodevalue = node1Element.getFirstChild().getNodeValue();
// Display values
Log.v(TAG, nodevalue);


141

•


Completed chart

Click


142

<Procedure>
1. XmlHelper parseDom class that implements the following processing
methods
1. Document object to retrieve XML data
2. Creates a DOM parser
3. Building parse XML into DOM tree
4. <id> <entry> to get the value in the tag, set the value to
RowModel
5. The id RowModel is set to the value obtained
6. <thumbnail> set the Rowmodel value to the value retrievd from
the “url” attribute.

1. Implementing Activity onClickDOMButton class
1. XmlHelper # parseDom shaping method to the data to obtain
RowModel ※ instance member variable "xmlHelper" is defined
in XmlHelper
143
2. TextView to display Commons License BY-NC-SA 4.0.
the analysis results

XmlHelper.java
public RowModel parseDom(Context context, String xml) {
// RowModel row = new RowModel();
RowModel rowModel = new RowModel();
try {
// Generate Dokyumentobirudafakutori
DocumentBuilderFactory dbfactory = DocumentBuilderFactory
.newInstance();
dbfactory.setNamespaceAware(true);
// get a stream of xml file
in = context.getAssets().open("sample.xml");
Document doc = builder.parse(in);
// Gets the root element (tag name: feed)
// Get <entry>
NodeList entryList = root.getElementsByTagName("entry");
// First get <entry>
Element entryElement = (Element) entryList.item(0);

144

Continued XmlHelper.java
/* <id> processing * /
/ / Get <id> obtained from <entry>
Element idElement = (Element) entryElement.getFirstChild();
/ / get the Text data obtained from <id>
String id = idElement.getFirstChild().getNodeValue();
// RowModel value set
rowModel.setId(id);
/* <description> processing * /
// Get <description> <entry> obtained from
NodeList desriptionList = entryElement.getElementsByTagName("description");
// Node information from text.
String summary = desriptionList.item(0).getFirstChild().getNodeValue();
// Cut off after 20 characters.
if (summary != null && 0 < summary.length()) {
if (20 < summary.length()) {
summary = summary.substring(0, 20);
}
}


145

// Node information from text.
String summary = desriptionList.item(0).getFirstChild().getNodeValue();
// Cut off after 20 characters.
}
}
rowModel.setSummary(summary);
/* <thumbnail> Processing * /
// <thumbnail> Get
NodeList thumbnailList = entryElement.getElementsByTagName("thumbnail");


146

// First get <thumbnail>
Element thumbnailElement = (Element) thumbnailList.item(0);
// <thumbnail> the "url" attribute gets the value of
String thumbnail = thumbnailElement.getAttribute("url");
rowModel.setThumbnailImageURL(thumbnail);
/* <title> processing * /
// <title> Get
NodeList titleList = entryElement.getElementsByTagName("title");
// Node information from text
String title = titleList.item(0).getFirstChild().getNodeValue();
rowModel.setTitle(title);


147

XmlHelper.java
public void onClickDOMButton(View v) {
RowModel rowModel = null;
// RowModel XmlHelper # parseDom get a call
rowModel = this.xmlHelper.parseDom(this, this.xml);
if (rowModel == null) {
this.textResult.setText ("Failed to retrieve data. ")
} else {
// TextView to display the contents of rowModel
this.textResult.setText(rowModel.toString());
}
}


148

6.2. create a mechanism to analyze XML(1)
Parsing XML Data
•WebAPI is retrieved using the HTTP data
communication with the following
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/"
xmlns:openSearch="http://a9.com/-/spec/opensearchrss/1.0/" xmlns:gd="http://schemas.google.com/g/2005"
xmlns:yt="http://gdata.youtube.com/schemas/2007">
:
- <entry>
<id>http://gdata.youtube.com/feeds/api/videos/fzzjgBAaWZw</id>
：
<media:group>
<media:description type="plain">ブログ・モア＊モアレmoire.lowdope.com</media:description>
：
<media:thumbnail url="http://i.ytimg.com/vi/fzzjgBAaWZw/2.jpg" height="90" width="120"
time="00:00:37" />
：
<media:title type="plain">だるまさんが転んにゃ - Stalking Cat -</media:title>
：
</media:group>
</entry>
</feed>

149

6.2. create a mechanism to analyze
XML(2)
•Exercise: making DOM, XMLPullParser,
SAX parsing process by using them.

•Retrieved from the XML data, analyzing
the following elements into Entity.
–id
–description
–thumbnail url
–title

150

•
Parsing XML with DOM
<Procedure>
•
Document object to retrieve XML data
•
DocumentBuilderFactory to create objects
•
Creates a DOM parser
•
DOM tree is built to amend the XML
•

Get the root element of XML data

•

Follows the DOM tree to get the desired node

•

To obtain the data held by the nodes (tags and text
data) .

151

•Parsing XML with DOM
public List<RowModel> parseTableModelDom(final String data)
throws IllegalStateException, IOException,
ParserConfigurationException, SAXException {
final List<RowModel> result = new ArrayList<RowModel>(MAX_RESULTS);
// Generate Dokyumentobirudafakutori
DocumentBuilderFactory dbfactory = DocumentBuilderFactory.newInstance();
dbfactory.setNamespaceAware(true);
InputSource is = new InputSource(new StringReader(data));
Document doc = builder.parse(is);
// Gets the root element (tag name: message)


152

•Parsing XML with DOM (cont'd)
NodeList entryList = root.getElementsByTagName("entry");
for (int i = 0; i < entryList.getLength(); i++) {
RowModel rowModel = new RowModel();
Element entryElement = (Element) entryList.item(i);
Element idElement = (Element) entryElement.getFirstChild();
String url = idElement.getFirstChild().getNodeValue();
rowModel.setUrl(url);
NodeList desriptionList = entryElement.getElementsByTagNameNS(
"http://search.yahoo.com/mrss/", "description");
String summary = desriptionList.item(0).getFirstChild()
.getNodeValue();
}
}
rowModel.setSummary(summary);
NodeList thumbnailList = entryElement.getElementsByTagNameNS(
"http://search.yahoo.com/mrss/", "thumbnail");
Element thumbnailElement = (Element) thumbnailList.item(0);
String thumbnail = thumbnailElement.getAttribute("url");
rowModel.setThumbnailImageURL(thumbnail);
NodeList titleList = entryElement.getElementsByTagNameNS(
"http://search.yahoo.com/mrss/", "title");
String title = titleList.item(0).getFirstChild().getNodeValue();
rowModel.setTitle(title);
result.add(rowModel);
}
return result;
}


153

6.2. SAX (repetition)
•SAX (event-driven)
• Such images that invoke the application parsing the parser.
• Iki read XML documents from his head, and start and end tags
• To strike, call the application of a fixed callback routine.
• By the application of the XML
• To make DOM not to read the document control
• Memory consumption is less than the DOM.
• Android is the conventional method of using the SAX,
• On SAX there are ways to use a wrapper.

Er is soooo ♪

！！！！！

My more
・・・ easy to use mon

SAX
DOM


154

6.2. XML is analyzed (SAX)
Parsing XML with SAX
<Procedure>
•

Creating a SAX event handler class to receive callbacks from the parser

•

To get SAX parser, create Pasafakutori SAX,

•

Set the SAX event handler class created by a parser

•

Start parsing an XML to be called back by an event handler created when the event occurred


155

•
•

DefaultHandler to create a subclass that inherits the class
Implement a process corresponding to each event

– Creating a SAX event handler class
to receive callbacks from the
parser at the start of implementation of the event
1.
Tag
2.
3.

Implementation of events at the end tag
Implementation of events in a text element


156

<method to override>
Return
value

Method Name

Description

void

startElement(String uri,
String localName,
String qName,
Attributes attributes)

Receive notification of the start of an element
Parameters
uri - namespace URI
localName - The local name prefix qualifier
qName - qualified name with a prefix
attributes - attributes that were added to the element

void

endElement(String uri,
String localName,
String qName)

Receive notification of the end of an element
Parameters
uri - namespace URI
localName - The local name prefix qualifier
qName - qualified name with a prefix

void

void characters(char[] ch,
int start,
int length)

Receives notification of character data inside an element
Parameters
ch - the character
start - starting position in the character array
length - number of characters from a character array to be used


157

•

Sample Code

<root>
</root>
※ The actual document does not break space


158

Sample Code
/ / get the stream to be parsed
InputSource is = new InputSource (new StringReader (xml));
/ / Create a parser Factory
SAXParserFactory saxParaser = SAXParserFactory.newInstance ();
try {
/ * Get the parser * /
SAXParser sp = saxParaser.newSAXParser ();
/ * Create an event handler * /
SaxHandler sh = new SaxHandler ();
/ * pass input data and event handlers to the event handler * /
sp.parse (is, sh);
} Catch (Exception e) {
e.printStackTrace ();
}


Create SAX parser

Parsing XML

159

Sample Code
class SaxHandler extends DefaultHandler {
/ / Tag start flag
boolean isNode1;
@ Override
public void startElement (String uri, String localName, String qName,
Attributes attributes) throws SAXException {
if ("node1". equals (localName)) {
/ / Node1 start tag
isNode1 = true;
}
}

Tag at the start of treatment

@ Override
public void endElement (String uri, String localName, String qName)
throws SAXException {
if ("node1". equals (localName)) {
/ / Node1 start tag
isNode1 = false;
}
}

@ Override
public void characters (char [] ch, int start, int length)
/ / Node1 tag if it is started, log text
if (isNode1) {
String nodevalue = new String (ch, start, length);
Log.v (TAG, nodevalue);
}
}
}

Tag at the end of treatment

Text Event Processing


160

•


Completed chart

Click


161

<Procedure>
XmlHelper DefaultHandler class to create a class that inherits the subclass
startElement, characters, endElement methods are implemented

XmlHelper parseSax class that implements the following processing
methods
Create a SAX parser object
XML parsing Hazime Hiraku
Implementing Activity onClickSAXButton class
XmlHelper # parseSax shaping method to the data to obtain RowModel
※ XmlHelper instance member variable "xmlHelper" is defined in
TextView to display the analysis results


162

＜XmlHelper.java＞

•

Answer
public RowModel parseSax (Context context, String xml) {
InputSource is = new InputSource (new StringReader (xml));
/ / Create a parser Factory
SAXParserFactory saxParaser = SAXParserFactory.newInstance ();
try {
/ / Get the parser
SAXParser sp = saxParaser.newSAXParser ();
/ / Create an event handler
SaxHandler sh = new SaxHandler ();
/ / pass the input data and an event handler to the event handler
sp.parse (is, sh);
return sh.rowModel;
e.printStackTrace ();
}
return null;
}

163

•

Answer

＜XmlHelper.java（ More ）＞

class SaxHandler extends DefaultHandler {
RowModel rowModel = new RowModel ();
/ / Tag start flag
boolean isEntry;
boolean isId = false;
boolean isSummary = false;
boolean isTitle = false;
boolean isThumbnail = false;
String id = null;
String summary = null;
String thumbnail = null;
String title = null;


164

＜XmlHelper.java（More）＞

•

Answer

@ Override
public void startElement (String uri, String localName, String qName,
Attributes attributes) throws SAXException {
/ / Entry to true if the tag is isEntry
if ("description". equals (localName)) {
/ / Entry tag begins
isEntry = true;
}
/ / Entry in the tag determines if
if (isEntry) {
if ("id". equals (localName)) {
isId = true;
}
if ("description". equals (localName)) {
isSummary = true;
}
if (! isThumbnail & & "thumbnail". equals (localName)) {
/ / Thumnail to get the url attribute of the tag
thumbnail = attributes.getValue ("url");
isThumbnail = true;

}
if ("title". equals (localName)) {
isTitle = true;
}
}
}


165

•

Answer


@ Override
public void endElement (String uri, String localName, String qName)
if ("entry". equals (localName)) {
/ / RowModel to set the value to
rowModel.setId (id);
rowModel.setSummary (summary);
rowModel.setThumbnailImageURL (thumbnail);
rowModel.setTitle (title);
/ / clear values
id = null;
summary = null;
thumbnail = null;
title = null;
isThumbnail = false;
isEntry = false;
}
}


166

•

Answer


@ Override
public void characters (char [] ch, int start, int length)
if (isEntry) {
if (isId) {
/ / Id to get
id = new String (ch, start, length);
isId = false;
}
if (isSummary) {
/ / Description to obtain
summary = new String (ch, start, length);
if (summary! = null & & 0 <summary.length ()) {
if (20 <length) {
summary = summary.substring (0, 20);
}
}
isSummary = false;
}
if (isTitle) {
/ / Title to get
title = new String (ch, start, length);
isTitle = false;
}
}
}


167

•

Answer

＜XmlSample.java＞

public void onClickSAXButton (View v) {
/ / XmlHelper # parseSax RowModel get a call
rowModel = this.xmlHelper.parseDom (this, this.xml);
if (rowModel == null) {
this.textResult.setText ("Failed to retrieve data. ")
} else {
/ / TextView to display the contents of rowModel
this.textResult.setText (rowModel.toString ());
}
}


168

6.2. XMLPullParser (repetition)
•

XMLPullParser (Pull Type)

•

SAX JAVA by what shall have the same functionality, so Android will not
support the same functionality that is available to XMLPullParser.

•

SAX as an XML document read from the head, performed by the application
of the load control, and can retrieve information from the parser, if necessary.

•

To make an application from the control, it is possible to stop the parsing
early that can significantly reduce the time required to parse.


169

6.2. XML is analyzed (XMLPullpaser)
•

Parsing XML with XMLPullpaser

<Procedure>
•
Create an XmlPullParser object
•

Passing a string parser to parse

•

XML to retrieve one event analysis


170

•

Sample Code

<root>
</root>
※ The actual document does not break space


171

Sample Code
try {
is = getAssets (). open ("samplea.xml");
/ / XmlPullParser XmlPullParser define
final XmlPullParser parser = Xml.newPullParser ();
/ / XmlPullParser pass a stream to parse the string
parser.setInput (new InputStreamReader (is));
parser.next (); / / root tag
parser.next (); / / node1 tags
/ / XmlPullParser to obtain the name of the tag
String tag = parser.getName ();
/ / XmlPullParser tag name is "node1", then
if ("node1". equals (tag)) {
parser.next ();
String nodevalue = parser.getText ();
Log.v (TAG, nodevalue);
}

Create parser XMLPullParser
Passing a string parser to parse

XML parsing events to get one at a time


172

•


Completed chart

Click


173

<Procedure>
XmlHelper parseXmlPullparser class method to implement the following
actions:
Define XmlPullParser
Passing a stream of string to parse
While processing one by one statement.
<id> <entry> to get the value in the tag, set the value to RowModel
<thumbnail> set the value to RowModel that retrived from the “url”
attribute.
Implementing Activity onClickXMLPullparserButton class
XmlHelper # parseXmlPullparser shaping method to the data to obtain
RowModel
※ XmlHelper instance member variable "xmlHelper" is defined in
TextView to display the analysis results

174

•

Answer

＜XmlHelper.java＞
public RowModel parseXmlPullparser (context, String xml) {
InputStream is = null;
try {
/ / Get the stream to be parsed
is = context.getAssets (). open ("sample.xml");
/ / XmlPullParser define
final XmlPullParser parser = Xml.newPullParser ();
/ / Pass the string to parse a stream of
parser.setInput (new InputStreamReader (is));
int eventType;
/ / XmlPullParser get the parsed hierarchy
final int depth = parser.getDepth ();
/ / XmlPullParser Perth exit conditions
/ / While processing the statements one at a time
while (((eventType = parser.next ())! = XmlPullParser.END_DOCUMENT | | parser.getDepth ()> depth)) {
/ / XmlPullParser eventType determine if a start tag
if (eventType == XmlPullParser.START_TAG) {
/ / XmlPullParser to obtain the name of the tag
String tag = parser.getName ();
/ / XmlPullParser tag name is "entry" if, parseToRowModel call
if ("entry". equals (tag)) {
rowModel = parseToRowModel (parser);
break;
}
}
}


175

•

Answer

＜XmlHelper.java＞（ More ）
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
}
}
}
return rowModel;
}


176

•

Answer
＜XmlHelper.java＞（More）
private RowModel parseToRowModel (XmlPullParser parser) throws XmlPullParserException, IOException {
RowModel rowModel = new RowModel ();
int eventType;
String tag = null;
/ / Get the hierarchy to Perth
final int depth = parser.getDepth ();
/ / End condition Perth
while (((eventType = parser.next ())! = XmlPullParser.END_DOCUMENT | | parser.getDepth ()> depth)) {
/ / EventType determine if a start tag
if (eventType == XmlPullParser.START_TAG) {
tag = parser.getName ();
/ / <entry> <id> To get the value in the tag, RowModel set the value to
if ("id". equals (tag)) {
/ / Move next.
parser.next ();
/ / Parser to get information from the text, rowModel set to the URL.
rowModel.setId (parser.getText ());
} Else if ("description". Equals (tag)) {
/ / Move next.
parser.next ();
/ / Parser to get information from the text.
String summary = parser.getText ();
/ / 20 characters, so cut fit.
if (summary! = null & & 0 <summary.length ()) {
if (20 <summary.length ()) {
summary = summary.substring (0, 20);
}
}


177

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