线程工具类ThreadUtils

1.pom引入guava依赖

<dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
      <version>23.0</version>
</dependency>

1.线程工具类ThreadUtils

import com.google.common.util.concurrent.ThreadFactoryBuilder;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.util.concurrent.*;

/**
 * thread utils
 */
public class ThreadUtils {


    private static final ThreadMXBean threadBean =  ManagementFactory.getThreadMXBean();
    private static final int STACK_DEPTH = 20;

    public static ThreadPoolExecutor newDaemonCachedThreadPool(String prefix){
        ThreadFactory threadFactory = namedThreadFactory(prefix);
        return ((ThreadPoolExecutor) Executors.newCachedThreadPool(threadFactory));
    }

    private static ThreadFactory namedThreadFactory(String prefix) {
        return new ThreadFactoryBuilder().setDaemon(true).setNameFormat(prefix + "-%d").build();
    }

    public static ThreadPoolExecutor newDaemonCachedThreadPool(String prefix ,
                                                               int maxThreadNumber,
                                                               int keepAliveSeconds){
        ThreadFactory threadFactory = namedThreadFactory(prefix);
        ThreadPoolExecutor threadPool = new ThreadPoolExecutor(
                // corePoolSize: the max number of threads to create before queuing the tasks
                maxThreadNumber,
                // maximumPoolSize: because we use LinkedBlockingDeque, this one is not used
                maxThreadNumber,
                keepAliveSeconds,
                TimeUnit.SECONDS,
                new LinkedBlockingQueue<Runnable>(),
                threadFactory);
        threadPool.allowCoreThreadTimeOut(true);
        return threadPool;
    }

    public static ThreadPoolExecutor newDaemonFixedThreadPool(int nThreads , String prefix){
        ThreadFactory threadFactory = namedThreadFactory(prefix);
        return ((ThreadPoolExecutor) Executors.newFixedThreadPool(nThreads, threadFactory));
    }

    public static ExecutorService newDaemonSingleThreadExecutor(String threadName){
        ThreadFactory threadFactory = new ThreadFactoryBuilder()
                .setDaemon(true)
                .setNameFormat(threadName)
                .build();
        return Executors.newSingleThreadExecutor(threadFactory);
    }

    public static ExecutorService newDaemonFixedThreadExecutor(String threadName,int threadsNum){
        ThreadFactory threadFactory = new ThreadFactoryBuilder()
                .setDaemon(true)
                .setNameFormat(threadName)
                .build();
        return Executors.newFixedThreadPool(threadsNum, threadFactory);
    }

    public static ScheduledExecutorService newDaemonThreadScheduledExecutor(String threadName, int corePoolSize) {
        return newThreadScheduledExecutor(threadName, corePoolSize, true);
    }

    public static ScheduledExecutorService newThreadScheduledExecutor(String threadName, int corePoolSize, boolean isDaemon) {
        ThreadFactory threadFactory = new ThreadFactoryBuilder()
                .setDaemon(isDaemon)
                .setNameFormat(threadName)
                .build();
        ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(corePoolSize, threadFactory);
        // By default, a cancelled task is not automatically removed from the work queue until its delay
        // elapses. We have to enable it manually.
        executor.setRemoveOnCancelPolicy(true);
        return executor;
    }

    public static ThreadInfo getThreadInfo(Thread t) {
        long tid = t.getId();
        return threadBean.getThreadInfo(tid, STACK_DEPTH);
    }

    public static String formatThreadInfo(ThreadInfo threadInfo, String indent) {
        StringBuilder sb = new StringBuilder();
        appendThreadInfo(sb, threadInfo, indent);
        return sb.toString();
    }

    public static void appendThreadInfo(StringBuilder sb,
                                        ThreadInfo info,
                                        String indent) {
        boolean contention = threadBean.isThreadContentionMonitoringEnabled();

        if (info == null) {
            sb.append(indent).append("Inactive (perhaps exited while monitoring was done)\n");
            return;
        }
        String taskName = getTaskName(info.getThreadId(), info.getThreadName());
        sb.append(indent).append("Thread ").append(taskName).append(":\n");

        Thread.State state = info.getThreadState();
        sb.append(indent).append("  State: ").append(state).append("\n");
        sb.append(indent).append("  Blocked count: ").append(info.getBlockedCount()).append("\n");
        sb.append(indent).append("  Waited count: ").append(info.getWaitedCount()).append("\n");
        if (contention) {
            sb.append(indent).append("  Blocked time: " + info.getBlockedTime()).append("\n");
            sb.append(indent).append("  Waited time: " + info.getWaitedTime()).append("\n");
        }
        if (state == Thread.State.WAITING) {
            sb.append(indent).append("  Waiting on ").append(info.getLockName()).append("\n");
        } else  if (state == Thread.State.BLOCKED) {
            sb.append(indent).append("  Blocked on ").append(info.getLockName()).append("\n");
            sb.append(indent).append("  Blocked by ").append(
                    getTaskName(info.getLockOwnerId(), info.getLockOwnerName())).append("\n");
        }
        sb.append(indent).append("  Stack:").append("\n");
        for (StackTraceElement frame: info.getStackTrace()) {
            sb.append(indent).append("    ").append(frame.toString()).append("\n");
        }
    }

    private static String getTaskName(long id, String name) {
        if (name == null) {
            return Long.toString(id);
        }
        return id + " (" + name + ")";
    }

    public static void sleep(final long millis) {
        try {
            Thread.sleep(millis);
        } catch (final InterruptedException ignore) {}
    }
}

2.经常使用的工具类方法

import java.util.concurrent.ThreadPoolExecutor;
...
ThreadPoolExecutor execService = (ThreadPoolExecutor) ThreadUtils.newDaemonFixedThreadExecutor("Executor-Thread", 20);