学步园

JDK线程 池：Executors.newFixedThreadPool ， Executors.newSingleThreadExecutor，由一个 ThreadFactory来创建新的线程，默认情况下为 Executors.defaultThreadFactory(),ThreadFactory接口

public interface ThreadFactory {
    Thread newThread(Runnable r);
}

我们可以采用自定义的ThreadFactory工厂。它创建一个新的MyAppThread实例，并将一个特定于线程池的名字传递给MyAppThread的构造函数，从而可以在线程转储和错误日志信息中区分来自不同线程池的线程。在应用程序的其他地方也可以使用MyAppThread，一边所有的线程都能使用它的调试功能

import java.util.concurrent.*;
public class MyThreadFactory implements ThreadFactory {
    private final String poolName;

    public MyThreadFactory(String poolName) {
        this.poolName = poolName;
    }

    public Thread newThread(Runnable runnable) {
        return new MyAppThread(runnable, poolName);
    }
}

在MyAppThread中还可以定制其他行为，如下面程序中，包括：为线程指定名字，设置自定义UncaughtExceptionHandler向Logger中写入信息，维护一些统计信息（包括有多少个线程被创建和销毁），以及在线程被创建或者终止时把调试消息写入日志

import java.util.concurrent.atomic.*;
import java.util.logging.*;
public class MyAppThread extends Thread {
    public static final String DEFAULT_NAME = "MyAppThread";
    private static volatile boolean debugLifecycle = false;
    private static final AtomicInteger created = new AtomicInteger();
    private static final AtomicInteger alive = new AtomicInteger();
    private static final Logger log = Logger.getAnonymousLogger();

    public MyAppThread(Runnable r) {
        this(r, DEFAULT_NAME);
    }

    public MyAppThread(Runnable runnable, String name) {
        super(runnable, name + "-" + created.incrementAndGet());
        setUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
            public void uncaughtException(Thread t,
                                          Throwable e) {
                log.log(Level.SEVERE,
                        "UNCAUGHT in thread " + t.getName(), e);
            }
        });
    }

    public void run() {
        //复制debug标志以确保一致的值
        boolean debug = debugLifecycle;
        if (debug) log.log(Level.FINE, "Created " + getName());
        try {
            alive.incrementAndGet();
            super.run();
        } finally {
            alive.decrementAndGet();
            if (debug) log.log(Level.FINE, "Exiting " + getName());
        }
    }

    public static int getThreadsCreated() {
        return created.get();
    }

    public static int getThreadsAlive() {
        return alive.get();
    }

    public static boolean getDebug() {
        return debugLifecycle;
    }

    public static void setDebug(boolean b) {
        debugLifecycle = b;
    }
}

下面是main方法调用

    public static void main(String args[]){
    	ExecutorService es = Executors.newFixedThreadPool(5, new MyThreadFactory("threadName"));
    }