關于Java多線程處理

主要是介紹一下Java的Callable的多線程問題

 
import java.util.concurrent.*;
import java.util.Date;
import java.util.List;
import java.util.ArrayList;
/**



Java線程：有返回值的線程 


@author wb_qiuquan.ying
*/

public class Test {
 @SuppressWarnings("rawtypes")
 public static void main(String[] args) throws ExecutionException,
   InterruptedException {
  int sizeNum = 5;
  // 創建一個線程池
  ExecutorService pool = Executors.newFixedThreadPool(sizeNum);
  // 創建多個有返回值的任務
  List<Future> list = new ArrayList<Future>();
  for (int i = 0; i < sizeNum; i++) {
//   Callable c = new MyCallable(i + " ");也可以這樣寫，運行結果一樣
   MyCallable c = new MyCallable(i + " ");
// 執行任務并獲取Future對象
   Future f = pool.submit(c);
   System.out.println("線程運行中此線程的值是:" + f.get().toString());
   list.add(f);
  }
  // 關閉線程池
 pool.shutdown();
  // 獲取所有并發任務的運行結果
  System.out.println("");
  for (Future f : list) {
   // 從Future對象上獲取任務的返回值，并輸出到控制臺
   System.out.println("關閉線程池后,各個線程的值:"+ f.get().toString());
  }
System.exit(0);
 }
}
class MyCallable implements Callable<Object> {
 private String taskNum;
 MyCallable(String taskNum) {
  this.taskNum = taskNum;
 }
    //call()方法
 public Object call() throws Exception {
  System.out.println(">>>" + taskNum + "call()方法任務啟動");
  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 "線程"+taskNum + "返回運行的時間【" + time + "毫秒】";
 }
}</pre></span>