Question

我正在创建一个JavaFX应用程序，我需要GUI来与类中的其他代码进行交互，但是如果没有我做出不同的Thread，GUI和另一段代码显然无法运行让他们继续前进。

public class Client extends Application {
public static void main(String[] args){
    launch(args);
}
@Override
public void start(Stage primaryStage){
    primaryStage.setTitle("Hello world!");
    Button btn = new Button();
    btn.setText("Run Client");

    btn.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent event) {
            try{runClient();}catch (Exception e){System.out.println("Exception Occurred, Server is down.");}
        }
    });


    StackPane root = new StackPane();
    root.getChildren().addAll(btn);
    primaryStage.setScene(new Scene(root, 500, 500));
    primaryStage.show();
}



public void runClient() throws Exception {
    String sentence;
    String modSentence;
    BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
    Socket clientSocket = new Socket("localhost", 6789);
    DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
    BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
    sentence = inFromUser.readLine();
    outToServer.writeBytes(sentence + "\n");
    modSentence = inFromServer.readLine();
    System.out.println("From Server: " + modSentence);
    clientSocket.close();
}

runClient()是服务器的客户端。我需要GUI与客户端进行通信，但我不能使新的Thread同时运行它们。

Answer 1

这就是我想你想要的。您创建了一个ExecutorService来处理多线程。然后使用execute（）向其提交任务。您可以阅读链接中的基础知识。

当你想从FXThread外部做一些UI时，你只需要打电话：

Platform.runLater(some Runnable with GUI code);

它在FXThread上运行。

public class Client extends Application {
    //Create a ExecutorService threadpool
    ExecutorService threadPool = Executors.newWorkStealingPool();

    public static void main(String[] args){
        launch(args);
    }

    @Override
    public void start(Stage primaryStage){
        primaryStage.setTitle("Hello world!");
        Button btn = new Button();
        btn.setText("Run Client");

        btn.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event) {
                try {
                    //submit a new task to the threadPool which will be executed on another thread.
                    threadPool.execute(new Runnable() {
                        @Override
                        public void run() {
                            runClient();
                        }
                    });
                } catch (Exception e) {
                    System.out.println("Exception Occurred, Server is down.");
                }
            }
        });

        StackPane root = new StackPane();
        root.getChildren().addAll(btn);
        primaryStage.setScene(new Scene(root, 500, 500));
        primaryStage.show();
    }

    public void runClient() throws Exception {
        String sentence;
        String modSentence;
        BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
        Socket clientSocket = new Socket("localhost", 6789);
        DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
        BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
        sentence = inFromUser.readLine();
        outToServer.writeBytes(sentence + "\n");
        modSentence = inFromServer.readLine();
        System.out.println("From Server: " + modSentence);
        clientSocket.close();

        //############# Run something in the FXThread #############\\
        Platform.runLater(new Runnable() {
            @Override
            public void run() {
                //do some UI stuff like updating labels
            }
        });
    }
}

修改
您应该使用哪个ExecutorService取决于您编写的应用程序类型。 WorkStealing对您来说可能不是最好的，但我不知道您的应用程序整体如何，所以我以它为例。您可以阅读有关不同线程池here的更多信息。

编辑2：
此外，如果您使用JavaFX-8，您可以使用Lambdas，这使您的代码更短。你可以写：

Platform.runLater(() -> { //DO STUFF HERE });

或

threadPool.execute(() -> { runClient(); });

或

btn.setOnAction(event -> { try { ... } catch(Exception e) { ... } });

如何使用JavaFX进行多线程处理

1 个答案: