CODEWITHSUNDEEP
javaclassclass-hierarchy
CoolPrase
CoolPrase

Reputation: 3

Going from a specific class up the tree to Object and getting their methods(without them being written more than once)

So I have a problem.My assingment untill tommorw is to make a java program,that gets a class,then writes its Name and methods,Then gets the one that it implements,does the same and continues up to Object.The problem is I have to make it so the methods don't repeat themselves.(Only the class that adds the method should print it out,the implementation of that class should no longer have it.) I made it so it prints everything only once,but it prints it out very strangely. Here is the code:

public static void main(String[] args) {
    Object o = new JRadioButton();
    Class cl;
    HashSet methodsnames = new HashSet();

    for (cl = o.getClass(); cl != null; cl = cl.getSuperclass()) {
       HashSet al = new HashSet();
       System.out.println(cl.getName()+ " - ");
       for (Method m : cl.getMethods()){
           boolean added = methodsnames.add(m.getName());
           if(added){
           al.add(m.getName());}
        }
       al.forEach(System.out::println);

        System.out.println("=============================");
    }
}

Upvotes: 0

Views: 47

Answers (3)

Edgard Leal
Edgard Leal

Reputation: 2720

Use getDeclaredMethods instead getMethods:

import java.lang.*;
import java.lang.reflect.*;
import java.util.*;
import javax.swing.*;

public class main
{
    public static void main(String ...args) {
        Object o = new JRadioButton();
        Class cl;
        HashSet methodsnames = new HashSet();

        for (cl = o.getClass(); cl != null; cl = cl.getSuperclass()) {
           HashSet al = new HashSet();
           System.out.println(cl.getName()+ " - ");
           for (Method m : cl.getDeclaredMethods()){
               boolean added = methodsnames.add(m.getName());
               if(added){
                   al.add(m.getName());
               }
           }
           al.forEach(System.out::println);

           System.out.println("=============================");
        }
    }
}

Check this code runing on Ideone.

Upvotes: 0

CoolPrase
CoolPrase

Reputation: 3

This did the trick for me: m.getDeclaringClass().equals(cl)

Upvotes: 0

Stefan Warminski
Stefan Warminski

Reputation: 1835

With Class#getMethods you get all public methods of the class - even the public methods provided by its super-class.

I think you want to print the method only if the class also provides the implementation so you need to check the declaring class: m.getDeclaringClass().equals(cl)

Upvotes: 2

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