Recursive get inheritance family , but It stop at It's super class.

Question

I make this class for the purpose to getting specified class name's inheritance family.
import java.util.*;
import java.lang.reflect.Field;
// A simple class for getting specify class name's super class family.
// Usage: java GetSuperClass java.util.ArrayList.
public class GetSuperClass {
  //recursive get super class.
  public static void get(String str) {
    Class ref = null;
    try {
      // get Class Objcet.
      ref = Class.forName(str);
    } catch(ClassNotFoundException e) {
      e.printStackTrace(System.err);
      System.exit(0);
      System.out.println(ref);
      System.out.println("field:");
      // get fields
      Field[] field = ref.getDeclaredFields();
      for(int i = 0; i < field.length; i++) {
        System.out.println(field);
//get super class
Class superClass= ref.getSuperclass();
//recursive call get()
if(superClass != null) {
get(superClass.toString());
return;
public static void main(String[] args) {
// must input a class name for getting super class family.
if(args.length != 1) {
System.out.println("incorrect parameters");
System.exit(0);
// call static method to start.
get(args[0]);
Input as into console command prompt.
java GetSuperClass java.util.ArrayListHere is result:
class java.util.ArrayList
field:
private static final long java.util.ArrayList.serialVersionUID
private transient java.lang.Object[] java.util.ArrayList.elementData
private int java.util.ArrayList.size
java.lang.ClassNotFoundException: class java.util.AbstractList
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at GetSuperClass.get(GetSuperClass.java:9)
at GetSuperClass.get(GetSuperClass.java:23)
at GetSuperClass.main(GetSuperClass.java:33)
Question: what's wrong with it?
Thanks for your response.

Answer 1

No need to lokup the super class! You already have it!
import java.util.*;
import java.lang.reflect.Field;
// A simple class for getting specify class name's super class family.
// Usage: java GetSuperClass java.util.ArrayList.
public class GetSuperClass
    public static void get(String str)
        Class ref = null;
        for (ClassLoader cl = GetSuperClass.class.getClassLoader(); cl != null; cl = cl.getParent())
            try
                // get Class Objcet.
                ref = Class.forName(str, false, System.class.getClassLoader());
            catch(ClassNotFoundException e)
                //e.printStackTrace(System.err);
        get(ref);
    private static void get(Class ref)
        System.out.println(ref);
        System.out.println("field:");
        // get fields
        Field[] field = ref.getDeclaredFields();
        for(int i = 0; i < field.length; i++)
            System.out.println(field);
//get super class
Class superClass= ref.getSuperclass();
//recursive call get()
if(superClass != null)
get(superClass);
return;
public static void main(String[] args)
// call static method to start.
get("java.util.ArrayList");