type Exception report

message Internal Server Error

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

exception 

java.lang.NullPointerException
        at DatabaseCheck.doGet(databasecheck.java:88)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
        at org.apache.catalina.core.StandardPipeline.invokeNext(Compiled Code)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:201)
        at org.apache.catalina.core.StandardPipeline.invokeNext(Compiled Code)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
        at org.apache.catalina.core.ContainerBase.invoke(Compiled Code)
        at org.apache.catalina.core.StandardContext.invoke(Compiled Code)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
        at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
        at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
        at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
        at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
        at org.apache.catalina.valves.AccessLogValve.invoke(Compiled Code)
        at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:163)
        at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
        at org.apache.catalina.connector.warp.WarpRequestHandler.handle(Compiled Code)
        at org.apache.catalina.connector.warp.WarpConnection.run(Compiled Code)
        at java.lang.Thread.run(Thread.java:479)