如何用参数调用方法表达式？

时间：2011-04-28 08:33:07

标签： jsf jsf-2

我可以将表达式作为方法表达式参数传递吗？

<p:dataTable id="gridRPBDetails" var="rpbDetail"
  value="#{tInputBean.detailList}"
  selection="#{tInputBean.selectedDetails}">

....

   <p:commandButton 
      process="@this" 
      action="#{tInputBean.querySubAnggaranListImpl(rpbDetail.map['budget'])}" ... />

....

</p:datatable>

我试过这个，但结果是例外：

DEBUG PhaseTracker - BEFORE PHASE INVOKE_APPLICATION 5
Apr 28, 2011 3:22:17 PM com.sun.faces.application.ActionListenerImpl processAction
SEVERE: java.lang.NullPointerException
javax.faces.el.MethodNotFoundException: java.lang.NullPointerException
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:104)
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
        at javax.faces.component.UICommand.broadcast(UICommand.java:315)
        at javax.faces.component.UIData.broadcast(UIData.java:915)
        at org.primefaces.component.datatable.DataTable.broadcast(DataTable.java:630)
        at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787)
        at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1252)
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
        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.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:383)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:288)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
        at java.lang.Class.isAssignableFrom(Native Method)
        at org.apache.el.util.ReflectionUtil.isAssignableFrom(ReflectionUtil.java:299)
        at org.apache.el.util.ReflectionUtil.getMethod(ReflectionUtil.java:172)
        at org.apache.el.parser.AstValue.invoke(AstValue.java:251)
        at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
        at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
        ... 25 more
Apr 28, 2011 3:22:17 PM com.sun.faces.lifecycle.InvokeApplicationPhase execute
WARNING: #{tInputBean.querySubAnggaranListImpl(rpbDetail.map['budget'])}: java.lang.NullPointerException
javax.faces.FacesException: #{tInputBean.querySubAnggaranListImpl(rpbDetail.map['budget'])}: java.lang.NullPointerException
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:110)
        at javax.faces.component.UICommand.broadcast(UICommand.java:315)
        at javax.faces.component.UIData.broadcast(UIData.java:915)
        at org.primefaces.component.datatable.DataTable.broadcast(DataTable.java:630)
        at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787)
        at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1252)
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
        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.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:383)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:288)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)
Caused by: javax.faces.el.MethodNotFoundException: java.lang.NullPointerException
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:104)
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
        ... 24 more
Caused by: java.lang.NullPointerException
        at java.lang.Class.isAssignableFrom(Native Method)
        at org.apache.el.util.ReflectionUtil.isAssignableFrom(ReflectionUtil.java:299)
        at org.apache.el.util.ReflectionUtil.getMethod(ReflectionUtil.java:172)
        at org.apache.el.parser.AstValue.invoke(AstValue.java:251)
        at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
        at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
        ... 25 more
DEBUG PhaseTracker - AFTER PHASE INVOKE_APPLICATION 5
javax.faces.FacesException: #{tInputBean.querySubAnggaranListImpl(rpbDetail.map['budget'])}: java.lang.NullPointerException
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:89)
        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.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:306)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:383)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:243)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:288)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)
Caused by: javax.faces.FacesException: #{tInputBean.querySubAnggaranListImpl(rpbDetail.map['budget'])}: java.lang.NullPointerException
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:110)
        at javax.faces.component.UICommand.broadcast(UICommand.java:315)
        at javax.faces.component.UIData.broadcast(UIData.java:915)
        at org.primefaces.component.datatable.DataTable.broadcast(DataTable.java:630)
        at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787)
        at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1252)
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
        ... 18 more
Caused by: javax.faces.el.MethodNotFoundException: java.lang.NullPointerException
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:104)
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
        ... 24 more
Caused by: java.lang.NullPointerException
        at java.lang.Class.isAssignableFrom(Native Method)
        at org.apache.el.util.ReflectionUtil.isAssignableFrom(ReflectionUtil.java:299)
        at org.apache.el.util.ReflectionUtil.getMethod(ReflectionUtil.java:172)
        at org.apache.el.parser.AstValue.invoke(AstValue.java:251)
        at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
        at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
        ... 25 more

这是我的操作方法（请注意，rpbDetail.map ['budget']是一种DataTransferObject，所以它应该适合）：

public void querySubAnggaranListImpl(DataTransferObject budget) {
    DebugUtil.start("querySubAnggaranListImpl");
    String budgetId = budget.getString("id");

    // cari subbudgetlist berdasarkan budgetId
    this.comboChainSubAnggaranList = ch.execute("common", "GetSubBudgetList", 
        new DataTransferObject()
            .putString("budgetId", budgetId))
        .getList("result");
    DebugUtil.end("querySubAnggaranListImpl");
}

我尝试了解决这个问题：action="#{tInputBean.querySubAnggaranListImpl(#{rpbDetail.map['budget']})}"，最后在我的浏览器上显示此错误消息：

  

/TInput.xhtml @ 161,40   行动= “＃{tInputBean.querySubAnggaranListImpl（＃{rpbDetail.map [ '预算']}）}”   标识符[＃]不是有效的Java   第1.19节要求的标识符   EL规范（标识符   :: = Java语言标识符）。这个   可以通过设置来禁用检查   系统属性   org.apache.el.parser.SKIP_IDENTIFIER_CHECK   为真。

如何将参数传递给方法表达式，就像上面的情况一样？

谢谢！

1 个答案:

答案 0 :(得分：0)

我终于发现这是我的错误。它应该是

rpbDetail.map.subBudget.map.budget.

rpbDetail.map.budget返回null，因此返回NullPointerException。

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