java.lang.NullPointerException

menglong_ 2017-07-11 09:06:30
上回好像也有过这样的错误没搞出来，这次调了半天还是没弄出来。感觉必须要求助了_(:з」∠)_
user取不到

报错信息：
java.lang.NullPointerException

action.LoginAction.login(LoginAction.java:20)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430)
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
java.lang.Thread.run(Thread.java:619)

struts配置信息
<struts>
<constant name="struts.devMode" value="true"></constant>
<constant name="sturts.ui.theme" value="simple"></constant>

<package name="common" namespace="/" extends="struts-default">
<action name="Userlogin_*" class="action.LoginAction" method="{1}">
<result name="success">/show.jsp</result>
</action>
</package>


</struts>

loginAction.java

public class LoginAction implements ModelDriven<AuthUser> {

private AuthUser user;
public AuthUser getModel() {
return user;
}

public String login(){

System.out.println(user.getPassword()); //报错的是这行，取不到user，user是null
ls.login(user.getPassword(), user.getUserName());
return "success";
}

private LoginService ls;
public LoginService getLs() {
return ls;
}

public void setLs(LoginService ls) {
this.ls = ls;
}
}

jsp文件：
<form action="Userlogin_login" method="post">
用户名：<input type="text" name="userName" id="userName"/><br/><br/>
密 码：<input type="password" name="password" id="password"/><br/><br/>
       
<input type="submit" class="btn" value="登录 " />
</form>
</body>
</html>

applicationContext配置文件：
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">

<context:property-placeholder location="classpath:dataSource.properties"/>

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="user" value="${user}"></property>
<property name="password" value="${password}"></property>
<property name="driverClass" value="${driverClass}"></property>
<property name="jdbcUrl" value="${jdbcUrl}"></property>
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="hibernateProperties" >
<props>
<prop key="format_sql">true</prop>
<prop key="show_sql">true</prop>
<prop key="dialect">org.hibernate.dialect.MySQLDialect</prop>
</props>

</property>
<property name="mappingLocations" value="classpath:crm/*/domain/*.hbm.xml"></property>

</bean>
<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">

</bean>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes >
<tx:method name="add*" />
<tx:method name="delete*" />
<tx:method name="change*" />
<tx:method name="select*" read-only="true" />

</tx:attributes>
</tx:advice>
<aop:config >
<aop:advisor advice-ref="txAdvice" pointcut="execution(* crm.*.service..*.*(..))"></aop:advisor>
</aop:config>

<import resource="applicationContext-staff.xml"></import>
</beans>
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qq_35942223 2017-07-12
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修改后的错误信息
qq_35942223 2017-07-12
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<import resource="applicationContext-staff.xml"></import>这个呢
menglong_ 2017-07-12
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修改后的错误信息是这个 Struts Problem Report Struts has detected an unhandled exception: Messages: File: action/LoginAction.java Line number: 33 Stacktraces java.lang.NullPointerException action.LoginAction.login(LoginAction.java:33) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450) com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563) org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2441) org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2430) java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) java.lang.Thread.run(Thread.java:619)
menglong_ 2017-07-11
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啊。找到第一个问题了。忘记user的get，set方法了。所以现在user可以取到了。。但是还是NullPointerException报错
menglong_ 2017-07-11
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第一次发帖可以有点丑。有点难看懂。。也不知道怎么写好。。哈哈
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