线程池控制一定数量的线程去处理业务

只有代码实现，具体基础知识请查看下面的博客（线程池+信号量）

https://blog.youkuaiyun.com/qq_33581278/article/details/84568675
https://blog.youkuaiyun.com/qq_33581278/article/details/84579454

1、自定义线程池

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

public class RecordDownloadExecutorPool
{
    private static final Logger logger = LogManager.getLogger(RecordDownloadExecutorPool.class);
    
    private RecordDownloadExecutorPool() {
        logger.info("JdbcExecutorPool created!");
    }
    
    private static class SingletonHolder {
        private static ExecutorService instance = new ThreadPoolExecutor(
                1000, 
                2000, 
                20, 
                TimeUnit.SECONDS, 
                new ArrayBlockingQueue<Runnable>(1), 
                new ThreadPoolExecutor.AbortPolicy()
                );
    }
    
    public static ExecutorService getInstance() {
        return SingletonHolder.instance;
    }
}

2、自定义控制线程池内运行线程数量类：bound为线程数量

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Semaphore;

public class MtCallPeakBoundedExecutor {
    private final ExecutorService executor;
    private final Semaphore semaphore;

    public MtCallPeakBoundedExecutor(ExecutorService executor, int bound) {
        this.executor = executor;
        this.semaphore = new Semaphore(bound);
    }
    
    public Semaphore getSemaphore() {
        return semaphore;
    }

    public void submitTask(final Runnable command) {
        try {
            semaphore.acquire();
            executor.execute(new Runnable() {
                @Override
                public void run() {
                    try {
                        command.run();
                    }finally {
                        semaphore.release();
                    }
                }
            });
        } catch (InterruptedException e) {
            semaphore.release();
        }
    }
}

3、自定义线程处理业务具体逻辑

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

public class DFTXRecordDownloadRunable implements Runnable {

    private static final Logger logger = LogManager.getLogger(DFTXRecordDownloadRunable.class);

    private String callId;
    private String fileName;

    public DFTXRecordDownloadRunable(String callId,String fileName) {
        super();
        this.callId = callId;
        this.fileName = fileName;
    }

    @Override
    public void run() {
        //具体处理业务逻辑
    }

}

4、如何使用

1. 初始化控制线程类，100为运行的线程数量，具体可以自己定义
   MtCallPeakBoundedExecutor mtCallPeakBoundedExecutor = new MtCallPeakBoundedExecutor(RecordDownloadExecutorPool.getInstance(), 100);
2. 初始化线程处理业务类
   DFTXRecordDownloadRunable dftxRecordDownloadRunable = new DFTXRecordDownloadRunable(callId,  fileName);
3. 处理业务类提交给线程池进行处理业务
   dtmtCallPeakBoundedExecutor.submitTask(dftxRecordDownloadRunable);