java.lang.NoClassDefFoundError: Could not initialize class java.util.Random

Question

package com.nodic.test;

import java.util.Random;

public class StopThread {
  private static User user = new User();

  public static class User {
    private int id;
    private String name;

    public User() {
      id  = 1;
      name = "1";
    }

    @Override
    public String toString() {
      return "{id=" + id + ", name=\"" + name + "\"}";
    }

    public String getName() {
      return name;
    }

    public void setName(String name) {
      this.name = name;
    }

    public int getId() {
      return id;
    }

    public void setId(int id) {
      this.id = id;
    }
  }

  public static class WriteThread implements Runnable {
    @Override
    public void run() {
      while(true) {
        synchronized (user) {
          int curr_id = new Random().nextInt();

          user.setId(curr_id);

          try {
            Thread.sleep(10000);
          } catch (InterruptedException e) {
            e.printStackTrace();
          }

          user.setName(String.valueOf(curr_id));
        }

        Thread.yield();
      }
    }
  }

  public static class ReadThread implements Runnable {
    @Override
    public void run() {
      while (true) {
        synchronized (user) {
          if(!user.getName().equals(String.valueOf(user.getId()))) {
            System.out.println(user.toString());
            break;
          }
        }

        Thread.yield();
      }
    }
  }

  public static void main(String[] args) {
    new Thread(new ReadThread(), "Thread-StopThread-ReadThread").start();

    int count = 0;

    while(count < 50) {
      Thread t = new Thread(new WriteThread(), "Thread-StopThread-WriteThread");
      t.start();

      t.stop();

      count ++;
    }
  }
}

HI every one, when i run this class with jdk1.8.0_45, why i always got this error: java.lang.NoClassDefFoundError: Could not initialize class java.util.Random

/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java -Didea.launcher.port=7534 "-Didea.launcher.bin.path=/Applications/IDE/IntelliJ IDEA /IntelliJ IDEA 14.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/lib/tools.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Users/huangshiqian/Workspaces/IDEA/Test/concurrent/target/classes:/Users/huangshiqian/.m2/repository/junit/junit/4.9/junit-4.9.jar:/Users/huangshiqian/.m2/repository/org/hamcrest/hamcrest-core/1.1/hamcrest-core-1.1.jar:/Applications/IDE/IntelliJ IDEA /IntelliJ IDEA 14.app/Contents/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain com.nodic.test.StopThread

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread"

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread"

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread"

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread"

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread"

Exception: java.lang.ThreadDeath thrown from the UncaughtExceptionHandler in thread "Thread-StopThread-WriteThread" Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-StopThread-WriteThread" java.lang.NoClassDefFoundError: Could not initialize class java.util.Random at com.nodic.test.StopThread$WriteThread.run(StopThread.java:44)

you didn't include java.lang.Thread and you didn't handled any exceptions,that could be your problem and i also agree with SMA,Are you sure you've set JAVA_HOME? — pouyan021, Jan 18 '16 at 12:20
i run it with intellij idea, and already set java_home in my environment echo $JAVA_HOME /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home — user3492549, Jan 18 '16 at 12:22
Possible duplicate of [Java: How interrupt/stop a thread?](http://stackoverflow.com/questions/6599202/java-how-interrupt-stop-a-thread) — Raedwald, Jan 18 '16 at 12:30

score 2 · Answer 1 · answered Jan 18 '16 at 13:27

You are most likely called stop() on a thread while it was running the static initialization for the Random class.

The JVM only attempts to initialize a class once.
If a classes initialization fails (because an exception was thrown), the JVM marks it, and any classes that depend on it ... as "bad". If you attempt to use it / them, you get a ClassDefNotFoundError.
The implementation for Thread.stop() is to cause the ThreadDeath exception to be thrown on the stack of the target thread.

In short, this is an example which illustrates why calling Thread.stop() is unsafe.

java.lang.NoClassDefFoundError: Could not initialize class java.util.Random

1 Answers1