Java通過Callable實現多執行緒
阿新 • • 發佈:2019-02-06
import java.util.concurrent.*;
import java.util.Date;
import java.util.List;
import java.util.ArrayList;
public class Test implements Callable<Object>{
private String taskNum;
Test(String taskNum) {
this.taskNum = taskNum;
}
public static void main(String[] args) throws ExecutionException,InterruptedException {
System.out .println("----程式開始執行----");
Date date1 = new Date();
int taskSize = 5;
// 建立一個執行緒池
ExecutorService pool = Executors.newFixedThreadPool(taskSize);
// 建立多個有返回值的任務
List<Future> list = new ArrayList<Future>();
for (int i = 0; i < taskSize; i++) {
Callable c = new Test(i + " ");
// 執行任務並獲取Future物件
Future f = pool.submit(c);
list.add(f);
}
// 關閉執行緒池
pool.shutdown();
// 獲取所有併發任務的執行結果
for (Future f : list) {
// 從Future物件上獲取任務的返回值,並輸出到控制檯
System.out.println(">>>" + f.get().toString());
}
Date date2 = new Date();
System.out.println("----程式結束執行----,程式執行時間【" + (date2.getTime() - date1.getTime()) + "毫秒】");
}
public Object call() throws Exception {
System.out.println(">>>" + taskNum + "任務啟動");
Date dateTmp1 = new Date();
Thread.sleep(1000);
Date dateTmp2 = new Date();
long time = dateTmp2.getTime() - dateTmp1.getTime();
System.out.println(">>>" + taskNum + "任務終止");
return taskNum + "任務返回執行結果,當前任務時間【" + time + "毫秒】";
}
}