Question

    static WebAppAccess webAppAccess;
    static 
    {

        String userId = webAppAccess.getVariables().getString(
        "moduleSelect_var");

        if(userId.equals("set"))

对于上面的代码我正在设置像这样的错误

The error message returned was: "Error in method main. java.lang.ExceptionInInitializerError".

请参阅已部署的应用程序中的logs文件夹以获取其他错误信息。

单击此处隐藏详细的错误消息。

Exception Error in method main. java.lang.ExceptionInInitializerError

Stack Trace
java.lang.ExceptionInInitializerError
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java(Compiled Code))
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java(Compiled Code))
    at java.lang.reflect.Constructor.newInstance(Constructor.java(Compiled Code))
    at java.lang.Class.newInstance3(Class.java(Compiled Code))
    at java.lang.Class.newInstance(Class.java(Compiled Code))
    at com.bowstreet.webapp.structures.VariableUtil.instantiateObjectValue(VariableUtil.java:203)
    at com.bowstreet.webapp.structures.RuntimeVariableImpl.getVariableValue(RuntimeVariableImpl.java:371)
    at com.bowstreet.webapp.structures.RuntimeVariableImpl.getValue(RuntimeVariableImpl.java:126)
    at com.bowstreet.webapp.structures.VariablesImpl.getVariableValue(VariablesImpl.java:584)
    at com.bowstreet.webapp.structures.VariablesImpl.getObject(VariablesImpl.java:388)
    at com.bowstreet.webapp.engine.actions.MethodAction.getMethodClassInstance(MethodAction.java:163)
    at com.bowstreet.webapp.engine.actions.MethodAction.callAction(MethodAction.java:86)
    at com.bowstreet.webapp.engine.WebAppAccessImpl.callMethod(WebAppAccessImpl.java:405)
    at genjava._qwe.main(_qwe.java:98)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java(Compiled Code))
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java(Compiled Code))
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java(Compiled Code))
    at java.lang.reflect.Method.invoke(Method.java(Compiled Code))
    at com.bowstreet.webapp.engine.actions.MethodAction.callAction(MethodAction.java:90)
    at com.bowstreet.webapp.engine.WebAppAccessImpl.callMethod(WebAppAccessImpl.java:405)
    at com.bowstreet.webapp.engine.WebAppAccessImpl.processAction(WebAppAccessImpl.java:1046)
    at com.bowstreet.webapp.engine.WebAppAccessImpl.processAction(WebAppAccessImpl.java:1146)
    at com.bowstreet.webapp.engine.WebAppRequestRunner.doRequest(WebAppRequestRunner.java:364)
    at com.bowstreet.webapp.engine.WebAppRunner.doActualRequest(WebAppRunner.java:866)
    at com.bowstreet.webapp.engine.WebAppRunner.doRequest(WebAppRunner.java:526)
    at com.bowstreet.webapp.engine.WebAppRunner.doRequest(WebAppRunner.java:291)
    at com.bowstreet.webapp.engine.WebAppRunner.doRequest(WebAppRunner.java:228)
    at com.bowstreet.webapp.engine.WebAppServlet.doPost(WebAppServlet.java:73)
    at com.bowstreet.webapp.engine.WebAppServlet.doGet(WebAppServlet.java:53)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:595)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:688)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
    at org.apache.geronimo.tomcat.valve.DefaultSubjectValve.invoke(DefaultSubjectValve.java:56)
    at org.apache.geronimo.tomcat.GeronimoStandardContext$SystemMethodValve.invoke(GeronimoStandardContext.java:342)
    at org.apache.geronimo.tomcat.valve.GeronimoBeforeAfterValve.invoke(GeronimoBeforeAfterValve.java:31)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
    at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:392)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:667)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:869)
    at java.lang.Thread.run(Thread.java:570)
Caused by: java.lang.NullPointerException
    at com.grpf.OuterClass.(OuterClass.java:28)
    ... 52 more

Answer 1

当webAppAccess上的某个方法仍然为空时，你会调用一个方法，你得到一个NullPointerException：

static WebAppAccess webAppAccess;
static 
{

    String userId = webAppAccess.getVariables().getString("moduleSelect_var");
    //              ^ here it is still null

    if(userId.equals("set"))

首先为其分配一个对象来解决它：

static WebAppAccess webAppAccess;
static 
{
    webAppAccess = new WebAppAccess(); // or whatever the constructor is...
    String userId = webAppAccess.getVariables().getString("moduleSelect_var");

    if(userId.equals("set"))

如何解决“方法main中的错误.java.lang.ExceptionInInitializerError”？

1 个答案: