带前缀命名的线程工厂，来自dubbo。

NamedThreadFactory.java

package com.alibaba.rocketmq.common;

import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 带前缀命名的线程工厂
 *
 * @author YAGNLiiN<yanglinf@gmail.com>
 * @since 2013-05-23
 */
public class NamedThreadFactory implements ThreadFactory {
    private static final AtomicInteger POOL_SEQ = new AtomicInteger(1);

    private final AtomicInteger mThreadNum = new AtomicInteger(1);

    private final String mPrefix;

    private final boolean mDaemo;

    private final ThreadGroup mGroup;

    public NamedThreadFactory() {
        this("pool-" + POOL_SEQ.getAndIncrement());
    }

    public NamedThreadFactory(String prefix) {
        this(prefix, false);
    }

    public NamedThreadFactory(String prefix, boolean daemo) {
        mPrefix = prefix + "-thread-";
        mDaemo = daemo;
        SecurityManager s = System.getSecurityManager();
        mGroup = (s == null) ? Thread.currentThread().getThreadGroup()
                            : s.getThreadGroup();
    }

    @Override
    public Thread newThread(Runnable runnable) {
        String name = mPrefix + mThreadNum.getAndIncrement();
        Thread ret = new Thread(mGroup, runnable, name, 0);
        ret.setDaemon(mDaemo);
        return ret;
    }

    public ThreadGroup getThreadGroup() {
        return mGroup;
    }
}