HTTP Status 500错误！！急！！

HTTP Status 500 -

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type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
    biz.ChaKanServlet.doGet(ChaKanServlet.java:612)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


note The full stack trace of the root cause is available in the Apache Tomcat/5.0.27 logs.


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Apache Tomcat/5.0.27

java.lang.NullPointerException

应该是代码中有对象没有初始化活没有初始化成功

记得我当时加上了这么一句

比如说：
Object o;
if(o==null){
  //这里初始化o对象;  
}