[英]JSF hiding exceptions?
我有一個JSF頁面的托管bean,它在構造函數中執行JPA調用以填充bean中的字段。 我在另一個持久化實體的調用(填充數據以進行測試)時遇到了一些麻煩。 我期待它會拋出某種異常,因為它不起作用,但我沒有得到任何東西。 僅僅是因為它,我嘗試了以下內容:
Query newQuery = em.createQuery("Bad Syntax");
List newList = newQuery.getResultList();
我希望這里有一個IllegalArgumentException
,因為查詢字符串完全無效,但頁面仍然加載,我在任何地方都看不到任何異常。
我是否正確期待這個例外? 如果是這樣,為什么我沒有看到它?
默認情況下,它不會禁止異常。 作為快速測試,我嘗試了以下方法:
package com.example;
import javax.faces.bean.ManagedBean;
@ManagedBean
public class Bean {
public Bean() {
throw new IllegalArgumentException("No!");
}
}
同
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>test</title>
</h:head>
<h:body>
#{bean}
</h:body>
</html>
我有一個很好的默認錯誤頁面,在webbrowser中有以下跟蹤:
javax.el.ELException: /test.xhtml: Cant instantiate class: com.example.Bean.
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:83)
at com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:75)
at com.sun.faces.facelets.compiler.UILeaf.encodeAll(UILeaf.java:176)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:619)
Caused by: com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: com.example.Bean.
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:405)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:267)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:86)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:61)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.faces.facelets.el.ELText$ELTextVariable.writeText(ELText.java:217)
at com.sun.faces.facelets.el.ELText$ELTextComposite.writeText(ELText.java:141)
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:78)
... 25 more
Caused by: java.lang.IllegalArgumentException: No!
at com.example.Bean.<init>(Bean.java:9)
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 java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188)
... 36 more
1-jun-2010 13:51:06 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet Faces Servlet threw exception
java.lang.IllegalArgumentException: No!
at com.example.Bean.<init>(Bean.java:9)
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 java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:405)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:267)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:86)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:61)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.faces.facelets.el.ELText$ELTextVariable.writeText(ELText.java:217)
at com.sun.faces.facelets.el.ELText$ELTextComposite.writeText(ELText.java:141)
at com.sun.faces.facelets.compiler.TextInstruction.write(TextInstruction.java:78)
at com.sun.faces.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:75)
at com.sun.faces.facelets.compiler.UILeaf.encodeAll(UILeaf.java:176)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:619)
所以你的問題可能就在其他地方。 你運行調試器了嗎?
好吧,似乎存在某種問題,NetBeans沒有正確地重新部署所有內容。 在我最初進行故障排除時,我一直在運行干凈的構建,但是在讓事情停留了幾天並回到它之后,我現在看到了我期望看到的東西。
引發者:java.lang.IllegalArgumentException:在EntityManager中創建查詢時發生異常:異常描述:解析查詢的語法錯誤[錯誤語法],第1行,第0列:意外令牌[錯誤]。
我不確定我從中學到了什么教訓,但它確實刪除了我對NetBeans的一些信任。
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