Thread Tips

1.把线程停掉方式

Thread.stop() 使用这种方式是不安全的，官方也不建议，使用如下代码

public abstract class StoppableRunnable implements Runnable {
    private volatile boolean stopWork;;
    private boolean done;

    public final void run() {
        setup();
        while(!stopWork && !done) {
            doUnitOfWork();
        }
        cleanup();
    }

    /**
     * Safely instructs this thread to stop working,
     * letting it finish it's current unit of work,
     * then doing any necessary cleanup and terminating
     * the thread.  Notice that this does not guarentee
     * the thread will stop, as doUnitOfWork() could
     * block if not properly implemented.
     */
    public void stop() {
        stopWork = true;
    }

    protected void done() {
        done = true;
    }

    protected void setup() { }
    protected void cleanup() { }

    /**
     * Does as small a unit of work as can be defined
     * for this thread.  Once there is no more work to
     * be done, done() should be called.
     */
    protected abstract void doUnitOfWork();
}

2.不要忽略中断异常

public void foo() {
  try {Thread.sleep(1000);}
  catch (InterruptedException e) {
    Thread.currentThread().interrupt();
  }
}

3.获取所有运行中线程

public static String[] getThreadNames() {
    ThreadGroup group = Thread.currentThread().getThreadGroup();
    ThreadGroup parent = null;
    while ( (parent = group.getParent()) != null ) {
      group = parent;
    }
    Thread[] threads = new Thread[group.activeCount()];
    group.enumerate(threads);
    java.util.HashSet set = new java.util.HashSet();
    for (int i=0; i < threads.length; ++i) {
      if (threads[i] != null && threads[i].isAlive()) {
        try {
          set.add(threads[i].getThreadGroup().getName()+","
                  +threads[i].getName()+","
                  +threads[i].getPriority());
        } catch (Throwable e) {e.printStackTrace();}
      }
    }
    String[] result = (String[]) set.toArray(new String[0]);
    java.util.Arrays.sort(result);
    return result;
  }

参考

http://www.billharlan.com/pub/papers/javatips.html