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Javascript 思考角度'；s$q.all使用Java并发

javascript java angularjs concurrency

Javascript 思考角度'；s$q.all使用Java并发,javascript,java,angularjs,concurrency,angular-promise,Javascript,Java,Angularjs,Concurrency,Angular Promise,在Angular.js库中，我们有一个api$q $q.all（）接受承诺数组，即 $q.all([promise1,promise2,....,promiseN]).then(function); 只有在解析传入参数的所有承诺后，才会解析回调函数 正如您在下面的代码中所看到的 <script type="text/javaScript"> angular.module("myApp",[]); angular.module("myA

在Angular.js库中，我们有一个api$q

$q.all（）接受承诺数组，即

$q.all([promise1,promise2,....,promiseN]).then(function);
只有在解析传入参数的所有承诺后，才会解析回调函数

正如您在下面的代码中所看到的

        <script type="text/javaScript">
        angular.module("myApp",[]);
        angular.module("myApp").controller("myCtrl",myCtrl);
        angular.module("myApp").factory("demoService",demoService);

        myCtrl.$inject = ["$scope","demoService","$q"];
        demoService.$inject = ["$q","$timeout"];

        function myCtrl($scope,demoService,$q){
            $scope.message = "All promises";

            $scope.init = init;


            function invokedAll(){
                var promises = [demoService.get(1),
                                demoService.get(2),
                                demoService.get(3),
                                demoService.get(4),
                                demoService.get(5),
                                demoService.get(6),
                                demoService.get(7),
                                demoService.get(8),
                                demoService.get(9),
                                demoService.get(10)];

                return $q.all(promises);                
            } //invokedAll

            function init(){
                invokedAll().then(function(){
                    console.log(" Data loaded successfully ");
                });
            }
        }

        function demoService($q,$timeout){
            var TIMEOUT = 2000; // 5 seconds
            return {
                get : function(messageNo){
                    TIMEOUT += 1000;
                    var deferred = $q.defer();
                    $timeout(function(){
                        console.log("data loaded "+messageNo);
                        deferred.resolve("success");
                    },TIMEOUT);

                    return deferred.promise;
                }
            };
        }   
    </script>
    <body ng-controller="myCtrl" ng-init="init()">
您可以看到，只有在所有承诺都得到解决之后，才会打印最后一行

我试图用java实现的上述功能

我正在使用ExecuterService api在线程池中执行任务

所有任务执行完毕后，调用final

代码如下：

 package executerService.example01;

 public class Example05 {
   private static final int POOL_COUNT = 10;

   private static void tasks() throws Exception{
      ExecutorService service = null;
      Set<Callable<Integer>> callables = null;
      List<Future<Integer>> futures = null;

      service = Executors.newFixedThreadPool(POOL_COUNT);

      callables = new HashSet<Callable<Integer>>();

      callables.add(new Callable<Integer>() {

        @Override
        public Integer call() throws Exception {
            int taskNo = 1;
            System.out.println(Thread.currentThread().getName()+", TASK-NO "+taskNo);
            return taskNo;
        }

      });

      callables.add(new Callable<Integer>() {

        @Override
        public Integer call() throws Exception {
            int taskNo = 2;
            System.out.println(Thread.currentThread().getName()+", TASK-NO "+taskNo);
            return taskNo;
        }

     });

     callables.add(new Callable<Integer>() {

        @Override
        public Integer call() throws Exception {
            int taskNo = 3;
            System.out.println(Thread.currentThread().getName()+", TASK-NO "+taskNo);
            return taskNo;
        }

     });


    futures = service.invokeAll(callables);


    for(Iterator<Future<Integer>> itr = futures.iterator(); itr.hasNext();){
        System.out.println("Execution of Task No "+itr.next().get()+" completed");
    }
  } //end of method task


  public static void main(String [] args){
      ExecutorService service = null;
      Future<Boolean> future = null;
      try{          
        service = Executors.newSingleThreadExecutor();

        future = service.submit(new Callable<Boolean>() {

            @Override
            public Boolean call() throws Exception {
                tasks();
                return true;
            }

        });

        if(future.get()){
            System.out.println("All the tasks are executed");
        }
      }catch(Exception e){
        e.printStackTrace();
      }
  } // end of main method
}

pool-2-thread-1, TASK-NO 2
pool-2-thread-2, TASK-NO 1
pool-2-thread-3, TASK-NO 3
Execution of Task No 2 completed
Execution of Task No 1 completed
Execution of Task No 3 completed
All the tasks are executed
我的问题是

我是否能够实现angular.js的“$q.all（）”的相同行为
在Java中使用“ExecuterService.invokeAll（）”和“Future.get（）”

如果我的理解是书面的，请指导我

还请让我知道，上面的Java实现是否正确，或者可以用不同的方式实现

什么行为？输出是一样的，不是吗？还请记住，js是一个线程，承诺可能看起来像java线程，但实际上它是完全不同的。它们甚至提供了一个allOf方法，可以让您非常接近JS的行为，但正如Petr所说，总会有一些语义差异 
pool-2-thread-1, TASK-NO 2
pool-2-thread-2, TASK-NO 1
pool-2-thread-3, TASK-NO 3
Execution of Task No 2 completed
Execution of Task No 1 completed
Execution of Task No 3 completed
All the tasks are executed