Question

java.lang.NullPointerException怎么解决

javax.servlet.ServletException
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
com.netsh.chat.util.ChkAllUserEnterChattingFilter.doFilter(ChkAllUserEnterChattingFilter.java:96)
com.netsh.chat.util.GetLoginUserInfoFilter.doFilter(GetLoginUserInfoFilter.java:37)
com.netsh.util.SetCharacterEncodingGBKFilter.doFilter(SetCharacterEncodingGBKFilter.java:28)
org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:406)

Answer 1

NullPointerException,既空指针异常、某个对象为空引起的
com.netsh.chat.util.ChkAllUserEnterChattingFilter.doFilter(ChkAllUserEnterChattingFilter.java:96)
大概从ChkAllUserEnterChattingFilter.java:96开始找起，应该能找到你某个对象

Answer 2

com.netsh.chat.util.ChkAllUserEnterChattingFilter.doFilter(ChkAllUserEnterChattingFilter.java:96)

这句出现null值
查看一下,如果是变量最好加上非空判断.

Answer 3

这些异常信息里那部分是你的代码，是org.tuckey.web 开头的包，还是com.netsh.chat.util的包，你找吧，从下往上找，挨个看是哪个类出现空指针了

Answer 4

空指针。你随着代码找下，看哪儿有一个地方引用是空的