自定义线程工厂

来源：互联网发布：虚拟机 mac osx 编辑：程序博客网时间：2024/06/04 01:34

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"));    }