在Jbuilder下编写socket程序，一个按钮新建了一个socket，如何在关闭按钮关闭这个连接？

Question

在按钮on_click事件中加上楼上所说的

Answer 1

问题没有解决。
我的代码如下，可是按下关闭按钮时，调试信息显示错误，见后文。
  Socket socket1;//连接按钮的事件
  void jBtncon_actionPerformed(ActionEvent e) {
    int port = Integer.parseInt(jTextField3.getText().trim());
  try {
    Socket socket1 = new Socket(jFormattedTextFieldIP.getText(), port);
  }
  catch (IOException ex) {
  }
  }//关闭连接
  void jButton3_actionPerformed(ActionEvent e) {
//    jBtncon_actionPerformed(ActionEvent e)
//test();
try {
  socket1.close();
}
catch (IOException ex) {
}  }
调试信息
C:\JBuilder9\jdk1.4\bin\javaw -classpath ";C:\JBuilder9\thirdparty\junit3.8\junit.jar;C:\JBuilder9\lib\unittest.jar;C:\JBuilder9\jdk1.4\demo\jfc\Java2D\Java2Demo.jar;C:\JBuilder9\jdk1.4\demo\plugin\jfc\Java2D\Java2Demo.jar;C:\JBuilder9\jdk1.4\jre\lib\charsets.jar;C:\JBuilder9\jdk1.4\jre\lib\jaws.jar;C:\JBuilder9\jdk1.4\jre\lib\jce.jar;C:\JBuilder9\jdk1.4\jre\lib\jsse.jar;C:\JBuilder9\jdk1.4\jre\lib\rt.jar;C:\JBuilder9\jdk1.4\jre\lib\sunrsasign.jar;C:\JBuilder9\jdk1.4\jre\lib\ext\dnsns.jar;C:\JBuilder9\jdk1.4\jre\lib\ext\ldapsec.jar;C:\JBuilder9\jdk1.4\jre\lib\ext\localedata.jar;C:\JBuilder9\jdk1.4\jre\lib\ext\sunjce_provider.jar;C:\JBuilder9\jdk1.4\jre\lib\im\indicim.jar;C:\JBuilder9\jdk1.4\lib\dt.jar;C:\JBuilder9\jdk1.4\lib\htmlconverter.jar;C:\JBuilder9\jdk1.4\lib\tools.jar"  

java.lang.NullPointerException
at frame1.jButton3_actionPerformed(Frame1.java:249)
at .Frame1_jButton3_actionAdapter.actionPerformed(Frame1.java:374)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1764)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1817)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:419)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:257)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:245)
at java.awt.Component.processMouseEvent(Component.java:5134)
at java.awt.Component.processEvent(Component.java:4931)
at java.awt.Container.processEvent(Container.java:1566)
at java.awt.Component.dispatchEventImpl(Component.java:3639)
at java.awt.Container.dispatchEventImpl(Container.java:1623)
at java.awt.Component.dispatchEvent(Component.java:3480)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3450)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3165)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3095)
at java.awt.Container.dispatchEventImpl(Container.java:1609)
at java.awt.Window.dispatchEventImpl(Window.java:1590)
at java.awt.Component.dispatchEvent(Component.java:3480)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:197)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:144)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:136)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:99)

Answer 2

Socket socket1 = new Socket(jFormattedTextFieldIP.getText(), port);
你这里是定义了一个局部变量，
可能你还定义了一下成员变量socket1

Answer 3

那么我就把成员变量定义注释掉，
但是如何在关闭按钮的方法中访问连接按钮方法中定义的局部变量socket1呢？谢谢！

Answer 4

try {
Socket socket1 = new Socket(jFormattedTextFieldIP.getText(), port);    socket1 = new Socket(jFormattedTextFieldIP.getText(), port);
  }
  catch (IOException ex) {
  }

Answer 5

没打好：
try {
//Socket socket1 = new Socket(jFormattedTextFieldIP.getText(), port);变成    socket1 = new Socket(jFormattedTextFieldIP.getText(), port);
  }
  catch (IOException ex) {
  }