私は IRC 用のサーバーに取り組んでおり、使用しているポートを編集できる構成画面を追加しましたが、Listen
それを有効にするにはクラスを再初期化する必要があるため、構成クラスに次のようにします:
Listen.closePorts();
new Listen();
そして、これが私のListenクラスです:
package server.network;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import server.Server;
import server.gui.GUIMain;
public class Listen {
private static Socket socket = null;
private int port;
public Listen() {
try {
port = Server.listenPort;
@SuppressWarnings("resource")
ServerSocket serverSocket = new ServerSocket(port);
GUIMain.jta.append("\nServer Started and listening for messages on port " + port + ".\n");
while(true) {
socket = serverSocket.accept();
InputStream is = socket.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String msg = br.readLine();
GUIMain.jta.append("Received message from client: " + msg + "\n");
}
} catch (Exception e) {
GUIMain.jta.append("Port " + port + " already in use!\n");
} finally {
try {
socket.close();
} catch(Exception e) { }
}
}
public static void closePorts() {
try {
socket.close();
GUIMain.jta.append("Server closed\n");
} catch (IOException e) { }
}
}
アプリケーションを起動すると、このクラスが実行され、指定されたポートでソケットが開かれますが、ここでポートを閉じようとすると:
public static void closePorts() {
try {
socket.close();
GUIMain.jta.append("Server closed\n");
} catch (IOException e) { }
}
それはハングアップしますsocket.close();
そして、コメントアウトしてクラスをリロードしようとして、ソケットを開いたままにしておくと、ポートが使用中のポートと同じ場合、Listen.closePorts();
ハングするか実行されます。catch()
簡単に言えば、クラスを再インストールして新しいポートを使用する前にソケットを閉じるにはどうすればよいですか?
これが完全な例外です。
java.lang.NullPointerException
at server.network.Listen.closePorts(Listen.java:44)
at server.gui.GUISettings.actionPerformed(GUISettings.java:86)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)