<a href="showStudenInfByIsRegister.action?student.isRegister=1">已注册——按类别显示学生信息</a> 问题是这样的:上面的语句是在jsp中 我想把isRegisterisRegister=1的值传到对应的action中但是我在日志输出isRegister的值时发现所出错的值是0(System.out.println("isRegister 的值为: "+student.getIsRegister());也就是说无法将jsp页面中设定的值传递到action中。
大家看下如何解决?JSP
大家看下如何解决?JSP
ActionContext.getContext().getParameters().get("student.isRegister");
int isRegister = Integer.parseInt(temp[0]);
"isRegister 的值为: "+student.getIsRegister():
里面的student是new出来的还是怎么来的
这个是在自己定义的student类中生成的get方法;我用的struts2。
我把你的代码复制到我的action中,并导入相应的包,启动tomcat时出错。
2013-4-12 11:40:06 org.apache.catalina.core.AprLifecycleListener init
信息: Loaded APR based Apache Tomcat Native library 1.1.16.
2013-4-12 11:40:06 org.apache.catalina.core.AprLifecycleListener init
信息: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
2013-4-12 11:40:06 org.apache.coyote.http11.Http11AprProtocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
2013-4-12 11:40:06 org.apache.coyote.ajp.AjpAprProtocol init
信息: Initializing Coyote AJP/1.3 on ajp-8009
2013-4-12 11:40:06 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 492 ms
2013-4-12 11:40:06 org.apache.catalina.core.StandardService start
信息: Starting service Catalina
2013-4-12 11:40:06 org.apache.catalina.core.StandardEngine start
信息: Starting Servlet Engine: Apache Tomcat/6.0.20
2013-4-12 11:40:07 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader).
log4j:WARN Please initialize the log4j system properly.
2013-4-12 11:40:10 org.apache.catalina.core.StandardContext listenerStart
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'showStudenInfByIsRegisterAction' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.mytest.action.Student.ShowStudentInfByIsRegisterAction]: Constructor threw exception; nested exception is java.lang.NullPointerException
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.mytest.action.Student.ShowStudentInfByIsRegisterAction]: Constructor threw exception; nested exception is java.lang.NullPointerException
Caused by: java.lang.NullPointerException
at com.mytest.action.Student.ShowStudentInfByIsRegisterAction.<init>(ShowStudentInfByIsRegisterAction.java:17)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:85)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:757)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:722)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:386)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:249)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:155)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:246)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:291)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:189)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3934)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4429)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:526)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:987)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:909)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:495)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1206)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:314)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:722)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:583)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
2013-4-12 11:40:10 org.apache.catalina.core.StandardContext start
严重: Error listenerStart
2013-4-12 11:40:10 org.apache.catalina.core.StandardContext start
严重: Context [/basicFunction] startup failed due to previous errors
2013-4-12 11:40:10 org.apache.catalina.core.ApplicationContext log
信息: Closing Spring root WebApplicationContext
2013-4-12 11:40:10 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader).
log4j:WARN Please initialize the log4j system properly.
AbandonedObjectPool is used (org.apache.commons.dbcp.AbandonedObjectPool@1890e38)
LogAbandoned: true
RemoveAbandoned: true
RemoveAbandonedTimeout: 180
2013-4-12 11:40:16 org.apache.coyote.http11.Http11AprProtocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2013-4-12 11:40:16 org.apache.coyote.ajp.AjpAprProtocol start
信息: Starting Coyote AJP/1.3 on ajp-8009
2013-4-12 11:40:16 org.apache.catalina.startup.Catalina start
信息: Server startup in 10014 ms运行后的结果如上所示。(我这里补充说明下: 在数据库里面 isregister 这个属性我是有设置默认值为0,也就是只能把默认值传到action里面,其实我的这种做法已经有实现过,但不知道这次怎么调试就是没有办法把jsp页面的值传过来。)
at com.mytest.action.Student.ShowStudentInfByIsRegisterAction.<init>(ShowStudentInfByIsRegisterAction.java:17)错误原因, 在你这个类com.mytest.action.Student.ShowStudentInfByIsRegisterAction第17行空指针异常,你检查下你的action里时候有Service的set方法,以及applicationcontext.xml中时候建立action与service的依赖。
如果还没解决,吧action这个类的17行所在的方法放出来,