java.lang.NoClassDefFoundError：无法初始化类java.util.Random

时间：2016-01-18 12:09:56

标签： java multithreading 

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 ++;
    }
  }
}

每个人，当我用jdk1.8.0_45运行这个类时，为什么我总是遇到这个错误：java.lang.NoClassDefFoundError：无法初始化类java.util.Random

  

/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java   -Didea.launcher.port = 7534＆＃34; -Didea.launcher.bin.path = / Applications / IDE / IntelliJ IDEA / IntelliJ   IDEA 14.app/Contents/bin" -Dfile.encoding = UTF-8 -classpath   ＆＃34; /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目录/ jfr.jar：/图书馆/的Java / JavaVirtual机/ jdk1.8.0_45.jdk /内容/首页/ JRE / lib中/ jfxswt.jar：/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/jsse.jar：/库/的Java / JavaVirtualMachines / jdk1.8.0_45.jdk /内容/首页/ JRE / lib目录/管理-agent.jar中：/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的.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 /内容/首页/ JRE / lib / ext目录/ SUNE c.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目录/ sunpkcs11.jar：/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/ext/zipfs.jar：/用户/ huangshiqian /工作区/ IDEA /测试/并行/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：/应用/ IDE /的IntelliJ   IDEA / IntelliJ IDEA 14.app/Contents/lib/idea_rt.jar"   com.intellij.rt.execution.application.AppMain   com.nodic.test.StopThread

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;   线程中的异常＆＃34; Thread-StopThread-WriteThread＆＃34;例外   thread＆＃34; Thread-StopThread-WriteThread＆＃34;例外：   从UncaughtExceptionHandler中抛出的java.lang.ThreadDeath   thread＆＃34; Thread-StopThread-WriteThread＆＃34;线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34;线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34;线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34;线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34;例外：java.lang.ThreadDeath   从线程中的UncaughtExceptionHandler抛出   ＆＃34;螺纹StopThread-WriteThread＆＃34;

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;

     

异常：抛出java.lang.ThreadDeath   线程中的UncaughtExceptionHandler＆＃34; Thread-StopThread-WriteThread＆＃34;   线程中的异常＆＃34; Thread-StopThread-WriteThread＆＃34;   java.lang.NoClassDefFoundError：无法初始化类   java.util.Random at   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）at at   java.lang.Thread.run（Thread.java:745）线程中的异常   ＆＃34;螺纹StopThread-WriteThread＆＃34; java.lang.NoClassDefFoundError：可以   不初始化java.util.Random类   com.nodic.test.StopThread $ WriteThread.run（StopThread.java:44）

1 个答案:

答案 0 :(得分：2)

在运行stop()类的静态初始化时，您很可能在线程上调用Random。

  • JVM只尝试初始化一次类。

  • 如果类初始化失败（因为抛出了异常），JVM会将其标记，并且任何依赖它的类......都是“坏”。如果您尝试使用它/它们，则会得到ClassDefNotFoundError。

  • Thread.stop()的实现是导致ThreadDeath异常被抛出到目标线程的堆栈上。

简而言之，这是一个说明调用Thread.stop()不安全的原因的例子。

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