请教Swing的一个调试技术.

不会Java不牛逼 2014-03-21 01:07:02

高手，您好：
我写的一个Swing程序，登录窗口，在进行了“提交按钮”的点击后，得到了：
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException
的报错，为了解决这个报错.
我把我的“登录窗口”Login类的代码，进行了如下的改造：
public Login() throws ClassCastException{
让我的“本类型的构造方法在面对本类型所有引用分支的时候”“抛出ClassCastException”.
并且，我将调用本类型的顶层类型的代码现场，进行了如下的代码书写：
try{
new Login();
}catch(ClassCastException e){
new NoteJFrameUserDportInfo02();
}
弹出一个JFrame窗口，让我的用户得到系统提示：
“尊敬的用户!!对不起!!本次连接由于网络异常,连接未果,请您重新登录,尝试连接我们的系统!!谢谢!!”.
但是，在今天小弟我运行程序的时候，仍然报错.
我的Login类的代码如下：

package c_port_packageBJTeacher;



import java.awt.Rectangle;

import java.awt.event.WindowEvent;

import java.awt.event.WindowListener;



import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.JTextField;





public class Login extends JFrame implements WindowListener{



	/**

	 * 

	 */

	public static String S_PORT_SERVER = "127.0.0.1";

	private static final long serialVersionUID = 1L;

	/**

	 * @param args

	 */

    static JTextField jtf0 = new JTextField();

	static JTextField jtf1 = new JTextField();

	JLabel jl0 = new JLabel();

	JLabel jl1 = new JLabel();

	MyJButton jb2 = null;

	MyJButtonPayForSysProduct jb3 = null;

	static JPasswordField jpwf = new JPasswordField();       

	JPanel jp1 = new JPanel();

	public static String UID = null;

	static String PWD = null;

    

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		new Login();

	}

	

	public Login() throws ClassCastException{

		this.setTitle("千里马网络教育平台,让您用每月一包烟钱,获得孩子的茁壮成长!!");

		jb2 = new MyJButton("注册","127.0.0.1");

		jb3 = new MyJButtonPayForSysProduct("验证产品授权");

		String MyUID0 = Login.jtf0.getText();

		String MyPWD0 = String.valueOf(Login.jpwf.getPassword());

		MyJButtonLogin jb1 = new MyJButtonLogin("登陆","",MyPWD0,this);

		this.setVisible(true);

		this.setDefaultCloseOperation(Login.EXIT_ON_CLOSE);

		jb1.setBounds(new Rectangle(10,220,80,30));

		jb2.setBounds(new Rectangle(250,220,80,30));

		jb3.setBounds(new Rectangle(110,220,120,30));

		jp1.setLayout(null);

		jp1.add(jb1);

		jp1.add(jb2);

		jp1.add(jb3);

		jtf0.setBounds(new Rectangle(73,115,220,25));

		jp1.add(jtf0);

		jpwf.setBounds(new Rectangle(73,150,220,25));

		jp1.add(jpwf) ;

		jl0 = new JLabel("用户名");

		jl1 = new JLabel("密码");

		jl0.setBounds(new Rectangle(30,115,40,25));

		jl1.setBounds(new Rectangle(30,150,40,25));

		jp1.add(jl0);

		jp1.add(jl1);

		jp1.add(jb3);

		this.add(jp1);

		this.setBounds(500,218,370,330);

		this.setContentPane(jp1);

		}



	@Override

	public void windowActivated(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}



	@Override

	public void windowClosed(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}



	@Override

	public void windowClosing(WindowEvent e) {

		 //TODO Auto-generated method stub

		Complete_C_port_registerfuct.so2.getMyResourceBack();

		PayforTheSoftWareOfDevelopmenter.so2.getMyResourceBack();

		MyJButtonLogin.so3.getMyResourceBack();

		SocketClient so3 = new SocketClient(Recv.S_PORT_SERVER,8811);

		so3.writeStr("7丗IHaveToExitMySys丗C丗Teacher丗"+NoteUserLoginFrame.MyworkNum,"Login");

		so3.getMyResourceBack();

		System.exit(0);

	}



	@Override

	public void windowDeactivated(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}



	@Override

	public void windowDeiconified(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}



	@Override

	public void windowIconified(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}



	@Override

	public void windowOpened(WindowEvent e) {

		// TODO Auto-generated method stub

		

	}

}

希望得到达人的相助：
我的修改方案，错在哪里？

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不会Java不牛逼 2014-03-21

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java.net.ConnectException: Connection refused: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) at java.net.AbstractPlainSocketImpl.connect(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.<init>(Unknown Source) at java.net.Socket.<init>(Unknown Source) at c_port_packageBJTeacher.SocketClient.<init>(SocketClient.java:38) at c_port_packageBJTeacher.MyJButtonLogin$1.actionPerformed(MyJButtonLogin.java:62) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$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) Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at c_port_packageBJTeacher.SocketClient.writeStr(SocketClient.java:60) at c_port_packageBJTeacher.MyJButtonLogin$1.actionPerformed(MyJButtonLogin.java:64) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$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) 我再一次遇到了这个报错. 上面是错误的完整版. 希望得到大家的相助：怎么写这段程序，能够用“捕获抛出异常”的手段，快速将错误，“cut了”.

不会Java不牛逼 2014-03-21

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引用

你这样是捕获不到异常的：
try{
new Login();
}catch(ClassCastException e){
new NoteJFrameUserDportInfo02();
}

很明显你地方都搞错了，而异常是事件调度线程抛出的，不是main线程抛出的；

既然你是点击button后出现异常，你应该检查下你那个“提交按钮”的事件监听器，然后捕获它就可以了;

你查看下你的button上的监听器，

这是我的项目上述场景下报出的错误.

求lxbccsu大神，CSDN中路过的高手们的“路见不平拔刀相助”！！
谢谢！！

不会Java不牛逼 2014-03-21

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谢谢lxbccsu高手高手高高手的点拨！！小弟，100分，全数奉上！！

lxbccsu 2014-03-21

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你这样是捕获不到异常的： try{ new Login(); }catch(ClassCastException e){ new NoteJFrameUserDportInfo02(); } 很明显你地方都搞错了，而异常是事件调度线程抛出的，不是main线程抛出的；既然你是点击button后出现异常，你应该检查下你那个“提交按钮”的事件监听器，然后捕获它就可以了; 你查看下你的button上的监听器，