ExecutorService的任务调度

r囧r小猫 2022-08-14 05:34 183阅读 0赞

**1、Callable** 用submit方法实现Callable有返回值  
  
import java.text.SimpleDateFormat;  
import java.util.ArrayList;  
import java.util.Date;  
import java.util.List;  
import java.util.concurrent.Callable;  
import java.util.concurrent.ExecutionException;  
import java.util.concurrent.ExecutorService;  
import java.util.concurrent.Executors;  
import java.util.concurrent.Future;  
  
public class CallableTaskTimer \{  
public static void main(String\[\] args) throws Exception\{  
ExecutorService executorService = Executors.newCachedThreadPool();  
List<Future<String>> resultList = new ArrayList<Future<String>>();  
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
Date beginDate = null;  
Date endDate = null;   
// 创建1000个任务并执行  
for (int i = 0; i < 1000; i++) \{  
// 使用ExecutorService执行Callable类型的任务，并将结果保存在future变量中  
Future<String> future = executorService.submit(new TaskWithResult(i,0));  
// 将任务执行结果存储到List中  
resultList.add(future);  
if(i == 0)\{  
beginDate = df.parse(df.format(new Date()));  
\}else if(i == 999)\{  
Thread.currentThread().sleep(1000);  
endDate = df.parse(df.format(new Date()));  
\}  
\}  
long l=beginDate.getTime()-endDate.getTime();  
long day=l/(24\*60\*60\*1000);  
long hour=(l/(60\*60\*1000)-day\*24);  
long min=((l/(60\*1000))-day\*24\*60-hour\*60);  
long s=(l/1000-day\*24\*60\*60-hour\*60\*60-min\*60);  
System.out.println(""+day+"天"+hour+"小时"+min+"分"+s+"秒");  
// 遍历任务的结果  
for (Future<String> fs : resultList) \{  
try \{  
System.out.println(fs.get()); // 打印各个线程（任务）执行的结果  
\} catch (InterruptedException e) \{  
e.printStackTrace();  
\} catch (ExecutionException e) \{  
e.printStackTrace();  
\} finally \{  
// 启动一次顺序关闭，执行以前提交的任务，但不接受新任务。如果已经关闭，则调用没有其他作用。  
executorService.shutdown();  
\}  
\}  
\}  
\}  
  
class TaskWithResult implements Callable<String> \{  
private int id;  
public TaskWithResult(int id) \{  
this.id = id;  
\}   
public TaskWithResult(int id,int temp) \{  
this.id = id;  
\}  
public String call() throws Exception \{  
System.out.println("call()方法被自动调用,干活！！！             "+ Thread.currentThread().getName());  
// 一个模拟耗时的操作  
for (int i = 999999; i > 0; i--);  
return "call()方法被自动调用，任务的结果是：" + id + "    "+ Thread.currentThread().getName();  
\}  
\}  
  
  
  
**2、Runnable** 用execute方法实现Runnable,无返回值  
  
import java.util.concurrent.ExecutorService;   
import java.util.concurrent.Executors;   
  
public class RunnableTask \{   
    public static void main(String\[\] args) \{   
   ExecutorService executorService = Executors.newCachedThreadPool();  
   for (int i = 0; i < 10; i++) \{ //开启1000个任务  
            executorService.execute(new TestRunnable());   
            System.out.println("任务：" + (i+1));   
   \}   
   executorService.shutdown();   
    \}   
\}   
  
class TestRunnable implements Runnable \{   
    public void run() \{   
        System.out.println("线程："+Thread.currentThread().getName());   
    \}   
\}