严重: Servlet.service() for servlet [jsp] threw exception java.lang.NullPointerException错误解决方法

最近运行项目一直出现这个报错：严重: Servlet.service() for servlet jsp threw exception试了很多办法，看了很多博文所说的方法进行解决还是解决不了。在自己的摸索中终于解决了。过程对我这个入门在来说脑大的很！下面分享我解决Servlet.service() for servlet jsp threw exception的方法给大家。
我的报错如下：
2019-4-29 9:13:54 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.index_jsp._jspInit(index_jsp.java:22)
at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:159)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.bjca.sso.filter.UamsFilter.doFilter(UamsFilter.java:45)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at hqwl.core.servlet.HQWLRequestFilter.doFilter(HQWLRequestFilter.java:122)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Http11ConnectionHandler.process(Http11Protocol.java:583)atorg.apache.tomcat.util.net.JIoEndpointWorker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:619)
AbandonedObjectPool is used

解决方法：

**报错原因：**项目jar包和tomcat的jar包冲突，不兼容。servlet-api.jar和jsp-api.jar加载失败。tomcat里lib下都会有这两个jar。而项目里 又写了这两个。同时存在servlet-api.jar和jsp-api.jar两jar发生冲突。
**解决方法：**停止MyEclipse运行到本机的Tomcat目录下的webapps\项目\lib里面删除servlet-api.jar和jsp-api.jar两jar删除掉。 例如这是我的Tomcat存放的路径D:\apache-tomcat-6.0.20\webapps\hqwl\WEB-INF\lib，我是到这个路径下删除servlet-api.jar和jsp-api.jar两jar的。（有时候解决了这个报错之后，运行项目几天又出现这个报错是因为你更新项目或者保存项目的时候Tomcat又自动帮你保存了这两个jar,同样该方法进行删除就好了）

**注意：**千万在MyEclipse里面通过项目删除，如图，否则不然会报错而且项目还会出现红色的感叹号和红叉！

不会解决的可以问我

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