java线程池任务队列 java 线程池 队列场景

线程池的应用场景【1】
场景：数据更新
待更新的数据较多，分布在多个mysql数据表中

准备：构造线程池

public class ThreadPoolManager {

    private final static int CORE_POOL_SIZE = 4;

    final static RejectedExecutionHandler HANDLER = (r, executor) -> System.out.println("工作队列被拒绝");

    public static final ThreadPoolExecutor THREAD_POOL
            = new ThreadPoolExecutor(CORE_POOL_SIZE, MAX_POOL_SIZE, KEEP_ALIVE_TIME, TimeUnit.SECONDS
            , new ArrayBlockingQueue(WORK_QUEUE_SIZE), HANDLER);
}

返回对象：

public class KeyInfoVO {
    public static final KeyInfoVO EMPTY = new KeyInfoVO ();
    private Integer UserId = 0;
    private Integer UserHomeId = 0;
    private Integer UserOtherId = 0;
    private Integer UserWorkId = 0;

    }

入参：

public class CompleteKeyInfo implements Serializable {
 public static final KeyInfo EMPTY = new KeyInfo();
 
    private Integer type;
    @ApiModelProperty("用户基本信息")
    private UserInfo userInfo ;
    @ApiModelProperty("用户家庭信息")
    private UserHomeInfo userHomeInfo ;
    @ApiModelProperty("用户其他信息")
    private UserOtherInfo userOtherInfo ;
    @ApiModelProperty("用户工作信息")
    private UserWorkInfo userWorkInfo ;
    
    
    }

具体使用场景：
利用多线程去更新数据

private static final Integer LATCH_COUNT = 4;
 
    public KeyInfoVO  modify(KeyInfo keyInfo) throws Exception {
       KeyInfoVO vo = new KeyInfoVO();
        final CountDownLatch latch = new CountDownLatch(LATCH_COUNT);
        ThreadPoolManager.THREAD_POOL.execute(() -> {
            Integer integer = userService.modify(keyInfo.getUserInfo());
            System.out.printf("--------------------"+integer);
            vo.setUserId(integer);
            latch.countDown();
        });
        ThreadPoolManager.THREAD_POOL.execute(() -> {
            Integer integer = UserHomeService.modify(keyInfo.getUserHomeInfo ());
            vo.setUserHomeId (integer);
            latch.countDown();
        });
        ThreadPoolManager.THREAD_POOL.execute(() -> {
            Integer integer = UserOtherService.modify(keyInfo.getUserOtherInfo ());
            vo.setUserOtherId (integer);
            latch.countDown();
        });
        ThreadPoolManager.THREAD_POOL.execute(() -> {
            Integer integer = UserWorkI.modify(keyInfo.getUserWorkInfo ());
            vo.setUserWorkId (integer);
            latch.countDown();
        });
        latch.await(20, TimeUnit.SECONDS);
        return vo;
    }