java.lang.NullPointerException（SMS）

我创建了这个程序服务器和客户端，通过蓝牙发送短信。我遇到了这个问题。我的客户端工作得很好，这个客户端工作得很好，但当我运行这个文件并按下“但我得到空点异常”时。我将感谢你的帮助

                LocalDevice.getLocalDevice().setDiscoverable(DiscoveryAgent.GIAC);

错误消息

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尝试在调用中添加新实例

public void actionPerformed（java.awt.event.ActionEvent evt）{

->

public void actionPerformed（new java.awt.event.ActionEvent evt）{

让我知道

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再见

如果上面这一行是您遇到异常的那一行，请检查LocalDevice.getLocalDevice（）是否真的返回了您期望的结果。如果没有，那就是您的问题。

遵循Anothem的建议。如果您使用的是jsr82，那只是API。开发人员应该自己实现

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或者，您可以下载Bluecove实现二进制文件。

stacktrace告诉您什么？类、方法和行号。从那里开始。如果您标记了错误发生的行，这将非常有帮助。例如267。您还可以打开大脑问自己，这行使用的值可能是null、

SMS\u SERVER.java

的第267行到底是什么内容？这无法编译，也没有任何意义。您好，谢谢您的回复，我尝试过了，但没有成功。请帮助我。

java.lang.NullPointerException
        at SMS_SERVER.jButton2ActionPerformed(SMS_SERVER.java:267)
        at SMS_SERVER.access$000(SMS_SERVER.java:27)
        at SMS_SERVER$1.actionPerformed(SMS_SERVER.java:101)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6289)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6054)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4652)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4482)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2478)
        at java.awt.Component.dispatchEvent(Component.java:4482)
        at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:644)
        at java.awt.EventQueue.access$000(EventQueue.java:85)
        at java.awt.EventQueue$1.run(EventQueue.java:603)
        at java.awt.EventQueue$1.run(EventQueue.java:601)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
        at java.awt.EventQueue$2.run(EventQueue.java:617)
        at java.awt.EventQueue$2.run(EventQueue.java:615)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:614)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)