堆栈跟踪中的数字是什么意思？

Question

我怎样才能在堆栈跟踪中使用这些数字？这些是什么意思？在eclipse中,我经常会遇到异常,例如NullPointerException:

java.lang.NullPointerException
  at com.sun.midp.lcdui.DefaultEventHandler.commandEvent(+68)
  at com.sun.midp.lcdui.AutomatedEventHandler.commandEvent(+47)
  at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.handleVmEvent(+186) 

Answer 1

这些是从方法开始引起异常的指令的偏移量.

java.lang.NullPointerException
  at com.sun.midp.lcdui.DefaultEventHandler.commandEvent(+68)

方法中偏移68处的指令com.sun.midp.lcdui.DefaultEventHandler.commandEvent通过访问空引用引起实际异常.

  at com.sun.midp.lcdui.AutomatedEventHandler.commandEvent(+47)

该方法中偏移47处的com.sun.midp.lcdui.AutomatedEventHandler.commandEvent指令是运行该com.sun.midp.lcdui.DefaultEventHandler.commandEvent方法的调用指令.

  at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.handleVmEvent(+186)

该方法中偏移量186处的com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.handleVmEvent指令是运行该com.sun.midp.lcdui.AutomatedEventHandler.commandEvent方法的调用指令.