相关疑难解决方法(0)

当尝试在EL中引用托管bean时#{bean.entity.property},有时会javax.el.PropertyNotFoundException: Target Unreachable抛出异常,通常是在设置bean属性时,或者要调用bean操作时.

似乎有五种不同的消息:

1. 目标无法访问,标识符'bean'已解析为null
2. 目标无法访问,'entity'返回null
3. 目标无法访问,'null'返回null
4. 目标无法访问,''0'返回null
5. 目标无法访问,'BracketSuffix'返回null

这些都意味着什么？它们是如何引起的,它们应该如何解决？

我得到转换器的新错误

javax.faces.component.UpdateModelException: java.lang.IllegalArgumentException: Cannot convert 5 of type class java.lang.Integer to class com.jpa.entity.Groups
    at javax.faces.component.UIInput.updateModel(UIInput.java:839)
    at javax.faces.component.UIInput.processUpdates(UIInput.java:722)
    at javax.faces.component.UIComponentBase.processUpdates(UIComponentBase.java:1108)
    at javax.faces.component.UIForm.processUpdates(UIForm.java:270)
    at javax.faces.component.UIComponentBase.processUpdates(UIComponentBase.java:1108)
    at javax.faces.component.UIComponentBase.processUpdates(UIComponentBase.java:1108)
    at javax.faces.component.UIViewRoot.processUpdates(UIViewRoot.java:1239)
    at com.sun.faces.lifecycle.UpdateModelValuesPhase.execute(UpdateModelValuesPhase.java:78)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
    at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
    at …