# Was heist "Component property class is not writable&quo



## freez (22. Nov 2007)

Hallo,

ich habe in meiner Facelets Applikation folgenden Fehler:

```
java.lang.IllegalArgumentException: Component property class is not writable
	at javax.faces.component._ComponentAttributesMap.setComponentProperty(_ComponentAttributesMap.java:410)
	at javax.faces.component._ComponentAttributesMap.put(_ComponentAttributesMap.java:312)
	at com.sun.facelets.tag.jsf.ComponentRule$LiteralAttributeMetadata.applyMetadata(ComponentRule.java:49)
	at com.sun.facelets.tag.MetadataImpl.applyMetadata(MetadataImpl.java:36)
	at com.sun.facelets.tag.MetaTagHandler.setAttributes(MetaTagHandler.java:62)
	at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:144)
	at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
	at com.sun.facelets.tag.ui.DefineHandler.apply(DefineHandler.java:58)
	at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:128)
	at com.sun.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:306)
	at com.sun.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:279)
	at com.sun.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:68)
	at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
	at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
	at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
	at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
	at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
	at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
	at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
	at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:143)
	at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:113)
	at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
	at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
	at com.sun.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:95)
	at com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:503)
	at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:546)
	at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41)
	at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:132)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:140)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:144)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833)
	at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639)
	at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285)
	at java.lang.Thread.run(Thread.java:595)
```

Weiß jemand, was das bedeuten kann? Mir fällt dazu erst mal gar nix ein, was das bedeuten kann.


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## maki (22. Nov 2007)

Das ist eine Exception 

Zeig uns doch mal deinen Code.


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## freez (22. Nov 2007)

Ja, das ist richtig 

habe das Problem zufällig beim Bearbeiten der Seite gefunden:


```
<t:div class="space" />
```

darf es nicht lauten, sondern entweder:


```
<div class="space" />
```

oder


```
<t:div styleClass="space" />
```

Die Exception ist da an der Stelle nicht wirklich aussagekräftig. Einen Verweis an die Stelle im Code der View hätte ich mir schon gewünscht.


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## maki (22. Nov 2007)

Willkommen bei JSF.

Schätze dich glücklich, überhaupt eine Fehlermeldung bekommen zu haben, und dann noch so eine aussagekräftige(kein Scherz).

Es ist eine gute Sache, allen(!) komponeneten IDs zuzuweisen, so hat man bessere Chancen auf hilfreiche Fehlermeldungen.


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