android 中除了更新UI的主執行緒以外，還需要處理業務邏輯的工作執行緒，所以需要我們構建執行緒池，對執行緒進行統一的管理.
android中像訪問記憶體卡，聯網等耗較長的操作時，需要在一部執行緒中使用|
1.編寫一個android使用的執行緒工具類
 

package com.dejun.commonsdk.thread;

import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Author:DoctorWei
 * Time:2018/12/22 14:13
 * Description:
 * email:
 
[email protected]
 */

public class ThreadManager {
    private static ThreadManager threadManager;
    /**
     * 懶漢多執行緒單例
     *
     * @return
     */
    public static ThreadManager getInstance() {
        if (threadManager == null) {
            synchronized (ThreadManager.class) {
                if (threadManager == null) {
                    threadManager = new ThreadManager();
                }
            }
        }
        return threadManager;
    }

    /**
     * 核心執行緒池的數量，同時能夠執行的執行緒數量
     */
    private int corePoolSize;
    /**
     * 最大執行緒池數量，表示當緩衝佇列滿的時候能繼續容納的等待任務的數量
     */
    private int maximumPoolSize;
    /**
     * 存活時間
     */
    private long keepAliveTime = 1;
    private TimeUnit unit = TimeUnit.HOURS;
    private ThreadPoolExecutor executor;

    private ThreadManager() {
        /**
         * 給corePoolSize賦值：當前裝置可用處理器核心數*2 + 1,能夠讓cpu的效率得到最大程度執行（有研究論證的）
         */
        corePoolSize = Runtime.getRuntime().availableProcessors() * 2 + 1;
        //雖然maximumPoolSize用不到，但是需要賦值，否則報錯
        maximumPoolSize = corePoolSize;
        executor = new ThreadPoolExecutor(
                //當某個核心任務執行完畢，會依次從緩衝佇列中取出等待任務
                corePoolSize,
                //5,先corePoolSize,然後new LinkedBlockingQueue<Runnable>(),然後maximumPoolSize,但是它的數量是包含了corePoolSize的
                maximumPoolSize,
                //表示的是maximumPoolSize當中等待任務的存活時間
                keepAliveTime,
                unit,
                //緩衝佇列，用於存放等待任務，Linked的先進先出
                new LinkedBlockingQueue<Runnable>(),
                //建立執行緒的工廠
                //  Executors.defaultThreadFactory(),
                new DefaultThreadFactory(Thread.NORM_PRIORITY, "tiaoba-pool-"),
                //用來對超出maximumPoolSize的任務的處理策略
                new ThreadPoolExecutor.AbortPolicy()
        );
    }

    /**
     * 執行任務
     *
     * @param runnable
     */
    public void execute(Runnable runnable) {
        if (executor == null) {
            //執行緒池執行者。
            //參1:核心執行緒數;參2:最大執行緒數;參3:執行緒休眠時間;參4:時間單位;參5:執行緒佇列;參6:生產執行緒的工廠;參7:執行緒異常處理策略
            executor = new ThreadPoolExecutor(
                    corePoolSize,
                    maximumPoolSize,
                    keepAliveTime,
                    TimeUnit.SECONDS,
                    new LinkedBlockingQueue<Runnable>(),
                    //   Executors.defaultThreadFactory(),
                    new DefaultThreadFactory(Thread.NORM_PRIORITY, "tiaoba-pool-"),
                    new ThreadPoolExecutor.AbortPolicy());
        }
        if (runnable != null) {
            executor.execute(runnable);
        }
    }

    /**
     * 移除任務
     */
    public void remove(Runnable runnable) {
        if (runnable != null) {
            executor.remove(runnable);
        }
    }

    /**
     * 建立執行緒的工廠，設定執行緒的優先順序，group，以及命名
     */
    private static class DefaultThreadFactory implements ThreadFactory {
        /**
         * 執行緒池的計數
         */
        private static final AtomicInteger poolNumber = new AtomicInteger(1);

        /**
         * 執行緒的計數
         */
        private final AtomicInteger threadNumber = new AtomicInteger(1);

        private final ThreadGroup group;
        private final String namePrefix;
        private final int threadPriority;

        DefaultThreadFactory(int threadPriority, String threadNamePrefix) {
            this.threadPriority = threadPriority;
            this.group = Thread.currentThread().getThreadGroup();
            namePrefix = threadNamePrefix + poolNumber.getAndIncrement() + "-thread-";
        }

        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement(), 0);
            if (t.isDaemon()) {
                t.setDaemon(false);
            }
            t.setPriority(threadPriority);
            return t;
        }
    }


}

2.使用

ThreadManager.getInstance().execute(new Runnable() {
    @Override
    public void run() {
 
    }
});