Java多线程批量数据导入的方法详解

import java.util.concurrent.atomic.AtomicLong;
/**
* 数据批量写入用的模拟服务
*
* @author RJH
* create at 2019-04-01
*/
public class MockService {
/**
* 可读取总数
*/
private long canReadTotal;
/**
* 写入总数
*/
private AtomicLong writeTotal=new AtomicLong(0);
/**
* 写入休眠时间（单位：毫秒）
*/
private final long sleepTime;
/**
* 构造方法
*
* @param canReadTotal
* @param sleepTime
*/
public MockService(long canReadTotal, long sleepTime) {
this.canReadTotal = canReadTotal;
this.sleepTime = sleepTime;
}
/**
* 批量读取数据接口
*
* @param num
* @return
*/
public synchronized long readData(int num) {
long readNum;
if (canReadTotal >= num) {
canReadTotal -= num;
readNum = num;
} else {
readNum = canReadTotal;
canReadTotal = 0;
}
//System.out.println("read data size:" + readNum);
return readNum;
}
/**
* 写入数据接口
*/
public void writeData() {
try {
// 休眠一定时间模拟写入速度慢
Thread.sleep(sleepTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
// 写入总数自增
System.out.println("thread:" + Thread.currentThread() + " write data:" + writeTotal.incrementAndGet());
}
/**
* 获取写入的总数
*
* @return
*/
public long getWriteTotal() {
return writeTotal.get();
}
}

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 基于线程池的多线程批量写入处理器
* @author RJH
* create at 2019-04-01
*/
public class SimpleBatchHandler {
private ExecutorService executorService;
private MockService service;
/**
* 每次批量读取的数据量
*/
private int batch;
/**
* 线程个数
*/
private int threadNum;
public SimpleBatchHandler(MockService service, int batch,int threadNum) {
this.service = service;
this.batch = batch;
//使用固定数目的线程池
this.executorService = Executors.newFixedThreadPool(threadNum);
}
/**
* 开始处理
*/
public void startHandle() {
// 开始处理的时间
long startTime = System.currentTimeMillis();
System.out.println("start handle time:" + startTime);
long readData;
while ((readData = service.readData(batch)) != 0) {// 批量读取数据，知道读取不到数据才停止
for (long i = 0; i < readData; i++) {
executorService.execute(() -> service.writeData());
}
}
// 关闭线程池
executorService.shutdown();
while (!executorService.isTerminated()) {//等待线程池中的线程执行完
}
// 结束时间
long endTime = System.currentTimeMillis();
System.out.println("end handle time:" + endTime);
// 总耗时
System.out.println("total handle time:" + (endTime - startTime) + "ms");
// 写入总数
System.out.println("total write num:" + service.getWriteTotal());
}
}

/**
* SimpleBatchHandler的测试类
* @author RJH
* create at 2019-04-01
*/
public class SimpleBatchHandlerTest {
public static void main(String[] args) {
// 总数
long total=100000;
// 休眠时间
long sleepTime=100;
// 每次拉取的数量
int batch=100;
// 线程个数
int threadNum=16;
MockService mockService=new MockService(total,sleepTime);
SimpleBatchHandler handler=new SimpleBatchHandler(mockService,batch,threadNum);
handler.startHandle();
}
}

start handle time:1554298681755
thread:Thread[pool-1-thread-2,5,main] write data:1
thread:Thread[pool-1-thread-1,5,main] write data:2
...省略部分输出
thread:Thread[pool-1-thread-4,5,main] write data:100000
end handle time:1554299330202
total handle time:648447ms
total write num:100000