An alternative to creation methods

1. UTAH STATE UNIVERSITY
COMPUTER SCIENCE
CS-7350
Creation Refactoring, based on “Refactoring to Patterns” Chapter 6 by Kerievsky, J.
Jorge Edison Lascano
Spring 2012
02-22-2012
Solving the nonstandard liability.Instead of using creation methods I think that a better way to
refactor many constructors(keeping a standard to instantiate) is passing an object as parameter to
every constructor. I made an experiment with a class Person and constructors to initialize
students, workers and professors; I am assuming no inheritance is needed. The
mechanics(omitting compile and test) is 1) find a class with several constructors:Person, 2)
implement a base constructor:Person(), 3) implement one class per constructor, every class with
an initialization constructor and public attributes as in the original constructors:Student{},
Worker{}, Professor{}, 4) review chained constructors, 5) find all callers and update them to
instantiate with the new constructors (see code).So far I am still using new after refactoring, and
the code looks clearer in the callers; but,with some over-engineering.See attached code for full
java implementation.
PersonaRefactorestRef=new PersonaRefactor(new Student("edi", "SLC",
15, 2));
PersonaRefactorwrkRef=new PersonaRefactor(new Worker("Genie", "Logan",
15, 2,30));

2. packagejavaperson;
/**
*
* @author elascano
*/
public class Main {
/**
* @paramargs the command line arguments
*/
public static void main(String[] args) {
// THIS CODE WITHOUT REFACTORING
Persona per=new Persona("dani","logan",41);
Persona est=new Persona("edi","logan",41,3);
Persona wrk=new Persona("vicki","logan",41,3,40);
Persona prf=new Persona("stephen","logan",41,4,20,5);
System.out.println("----------------Persona--------------");
per.print();
System.out.println("----------------Student--------------");
est.print();
System.out.println("----------------Worker--------------");
wrk.print();
System.out.println("----------------Professor--------------");
prf.print();
// THIS CODE WITH REFACTORING
PersonaRefactorperRef=new PersonaRefactor("george","quito",18);
PersonaRefactorestRef=new PersonaRefactor(new Student("hao", "SLC", 15, 2));
PersonaRefactorwrkRef=new PersonaRefactor(new Worker("Genie", "Logan", 15, 2,30));
PersonaRefactorprfRef=new PersonaRefactor(new Professor("Edison", "North Logan", 15, 4, 20, 6));
//System.out.println("----------------Persona--------------");
//per.print();
System.out.println("----------------Student--------------");
estRef.print();
System.out.println("----------------Worker--------------");
wrkRef.print();
System.out.println("----------------Professor--------------");
prfRef.print();
}
}
packagejavaperson;
/**
*
* @authorelascano
*/
class Persona {
private String name="";
private String city="";
privateint age=0;
privateintstudyLevel=0;
privateintweekWorkHours=0;
privateinttaughtCourses=0;
//construct a person
public Persona(String n, String c, int a){
name=n;
city=c;
age=a;
}
//contruct a student

3. public Persona(String n, String c, int a, int l){
//new Persona(n, c, a);
this(n,c,a);
studyLevel=l;
}
//contruct a worker
public Persona(String n, String c, int a, int l, int h){
//new Persona(n, c, a);
this(n,c,a,l);
weekWorkHours=h;
}
//contruct a professor
public Persona(String n, String c, int a, int l, int h, int t){
//new Persona(n, c, a);
this(n,c,a,l,h);
taughtCourses=t;
}
public void print(){
System.out.println("name : "+name);
System.out.println("city : "+city);
System.out.println("age : "+age);
System.out.println("level of studies : "+studyLevel);
System.out.println("weekly hours : "+weekWorkHours);
System.out.println("taught courses : "+taughtCourses);
}
}
packagejavaperson;
/**
*
* @author elascano
*/
public class PersonaRefactor {
private String name="";
private String city="";
privateint age=0;
privateintstudyLevel=0;
privateintweekWorkHours=0;
privateinttaughtCourses=0;
//construct a person
publicPersonaRefactor(String n, String c, int a){
name=n;
city=c;
age=a;
}
//contruct a student
publicPersonaRefactor(Student S){
//new Persona(n, c, a);
this(S.name, S.city, S.age);
studyLevel=S.studyLevel;
}
//contruct a worker
publicPersonaRefactor(Worker W){
//new Persona(n, c, a);
this(new Student(W.name, W.city, W.age, W.studyLevel));
weekWorkHours=W.weekWorkHours;
}
//contruct a professor
publicPersonaRefactor(Professor P){
//new Persona(n, c, a);

4. this(new Worker(P.name, P.city, P.age, P.studyLevel, P.weekWorkHours));
taughtCourses=P.taughtCourses;
}
public void print(){
System.out.println("name : "+name);
System.out.println("city : "+city);
System.out.println("age : "+age);
System.out.println("level of studies : "+studyLevel);
System.out.println("weekly hours : "+weekWorkHours);
System.out.println("taught courses : "+taughtCourses);
}
}
class Student{
public String name="";
public String city="";
publicint age=0;
publicintstudyLevel=0;
//construct a person
public Student(String n, String c, int a, int l){
name=n;
city=c;
age=a;
studyLevel=l;
}
}
class Worker{
public String name="";
public String city="";
publicint age=0;
publicintstudyLevel=0;
publicintweekWorkHours=0;
//construct a person
public Worker(String n, String c, int a, int l, int h){
name=n;
city=c;
age=a;
studyLevel=l;
weekWorkHours=h;
}
}
class Professor{
public String name="";
public String city="";
publicint age=0;
publicintstudyLevel=0;
publicintweekWorkHours=0;
publicinttaughtCourses=0;
//construct a person
public Professor(String n, String c, int a, int l, int h, int t){
name=n;
city=c;
age=a;
studyLevel=l;
weekWorkHours=h;
taughtCourses=t;
}
}