Java RMI圖形介面應用程式
在上一章中，我們建立了一個RMI應用程式的範例。 在本章中，我們將介紹如何建立一個用戶端呼叫顯示GUI視窗(基於JavaFX)的RMI應用程式。
定義遠端介面
在這裡，首先定義一個名稱為Hello的遠端介面，此介面中有一個名稱為animation()的方法。
import java.rmi.Remote;
import java.rmi.RemoteException;
// Creating Remote interface for our application
public interface Hello extends Remote {
void animation() throws RemoteException;
}
開發實現類
在本應用程式的Implementation類(遠端物件)中，將建立一個使用JavaFX顯示GUI內容的視窗。建立一個Java原始碼檔案：FxSample.java，其程式碼如下所示 -
import javafx.animation.RotateTransition;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.PerspectiveCamera;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.input.KeyEvent;
import javafx.scene.paint.Color;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Box;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;
import javafx.scene.text.Text;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import javafx.util.Duration;
// Implementing the remote interface
public class FxSample extends Application implements Hello {
@Override
public void start(Stage stage) {
// Drawing a Box
Box box = new Box();
// Setting the properties of the Box
box.setWidth(150.0);
box.setHeight(150.0);
box.setDepth(100.0);
// Setting the position of the box
box.setTranslateX(350);
box.setTranslateY(150);
box.setTranslateZ(50);
// Setting the text
Text text = new Text(
"Type any letter to rotate the box, and click on the box to stop the rotation");
// Setting the font of the text
text.setFont(Font.font(null, FontWeight.BOLD, 15));
// Setting the color of the text
text.setFill(Color.CRIMSON);
// Setting the position of the text
text.setX(20);
text.setY(50);
// Setting the material of the box
PhongMaterial material = new PhongMaterial();
material.setDiffuseColor(Color.DARKSLATEBLUE);
// Setting the diffuse color material to box
box.setMaterial(material);
// Setting the rotation animation to the box
RotateTransition rotateTransition = new RotateTransition();
// Setting the duration for the transition
rotateTransition.setDuration(Duration.millis(1000));
// Setting the node for the transition
rotateTransition.setNode(box);
// Setting the axis of the rotation
rotateTransition.setAxis(Rotate.Y_AXIS);
// Setting the angle of the rotation
rotateTransition.setByAngle(360);
// Setting the cycle count for the transition
rotateTransition.setCycleCount(50);
// Setting auto reverse value to false
rotateTransition.setAutoReverse(false);
// Creating a text filed
TextField textField = new TextField();
// Setting the position of the text field
textField.setLayoutX(50);
textField.setLayoutY(100);
// Handling the key typed event
EventHandler<KeyEvent> eventHandlerTextField = new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {
// Playing the animation
rotateTransition.play();
}
};
// Adding an event handler to the text feld
textField.addEventHandler(KeyEvent.KEY_TYPED, eventHandlerTextField);
// Handling the mouse clicked event(on box)
EventHandler<javafx.scene.input.MouseEvent> eventHandlerBox =
new EventHandler<javafx.scene.input.MouseEvent>() {
@Override
public void handle(javafx.scene.input.MouseEvent e) {
rotateTransition.stop();
}
};
// Adding the event handler to the box
box.addEventHandler(javafx.scene.input.MouseEvent.MOUSE_CLICKED, eventHandlerBox);
// Creating a Group object
Group root = new Group(box, textField, text);
// Creating a scene object
Scene scene = new Scene(root, 600, 300);
// Setting camera
PerspectiveCamera camera = new PerspectiveCamera(false);
camera.setTranslateX(0);
camera.setTranslateY(0);
camera.setTranslateZ(0);
scene.setCamera(camera);
// Setting title to the Stage
stage.setTitle("Event Handlers Example");
// Adding scene to the stage
stage.setScene(scene);
// Displaying the contents of the stage
stage.show();
}
// Implementing the interface method
public void animation() {
launch();
}
}
伺服器程式
RMI伺服器程式應實現遠端介面或擴充套件實現類。 在這裡，應該建立一個遠端物件並將其系結到RMIregistry。
以下是本應用程式的伺服器程式。在這裡，我們將擴充套件上述建立的類，建立一個遠端物件，並使用系結名稱：hello 將其註冊到RMI登錄檔。建立一個Java原始碼檔案：Server.java，其程式碼如下所示 -
import java.rmi.registry.Registry;
import java.rmi.registry.LocateRegistry;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
public class Server extends FxSample {
public Server() {}
public static void main(String args[]) {
try {
// Instantiating the implementation class
FxSample obj = new FxSample();
// Exporting the object of implementation class
// (here we are exporting the remote object to the stub)
Hello stub = (Hello) UnicastRemoteObject.exportObject(obj, 0);
// Binding the remote object (stub) in the registry
Registry registry = LocateRegistry.getRegistry();
registry.bind("Hello", stub);
System.err.println("Server ready");
} catch (Exception e) {
System.err.println("Server exception: " + e.toString());
e.printStackTrace();
}
}
}
用戶端程式
以下是本應用程式的用戶端程式。 在這裡，我們提取遠端物件並呼叫其animation()方法。建立一個Java原始碼檔案：Client.java，其程式碼如下所示 -
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
public class Client {
private Client() {}
public static void main(String[] args) {
try {
// Getting the registry
Registry registry = LocateRegistry.getRegistry(null);
// Looking up the registry for the remote object
Hello stub = (Hello) registry.lookup("Hello");
// Calling the remote method using the obtained object
stub.animation();
System.out.println("Remote method invoked");
} catch (Exception e) {
System.err.println("Client exception: " + e.toString());
e.printStackTrace();
}
}
}
執行範例的步驟
以下是執行RMI範例的步驟。
第一步 - 開啟儲存所有程式的檔案夾，並編譯所有Java檔案，如下所示。
F:\worksp\java_rmi\java-gui>javac *.java
F:\worksp\java_rmi\java-gui>
第二步 - 使用以下命令啟動rmi登錄檔。
start rmiregistry
這將在單獨的視窗中啟動一個rmi登錄檔，如下所示。
第三步 - 執行伺服器類檔案，如下所示。
F:\worksp\java_rmi\java-gui>java Server
Server ready
第四步 - 執行用戶端類檔案，如下所示。
F:\worksp\java_rmi\java-gui> java Client
驗證呼叫結果 - 當啟動用戶端以後，將在伺服器中看到啟動一個圖形介面，如下所示 -
