Something for the german speaking people:
javax.faces.event.MethodExpressionActionListener processAction
SCHWERWIEGEND: Beim Aufrufen des Aktionszielgeräts 'java.lang.NullPointerException'
für Komponente '#{reportingBean.createPdfReport}' wurde 'j_id84' erhalten.
Isn’t it wonderfull to read error messages in your mother tongue? But who does understand what this means??
Besonders schön finde ich das Aktionszielgerät NullPointerException und dass eine ID erhalten wird. Super!
Sometimes the problem with validators is that you can’t send a cancel button from within a form, because the validator stops processing it. In this case it is usefull to set the button on immediate=”true”, but then the problem might be that the view ist not correctly cleared. To force clearing the view, it is important to navigate with an outcome other than null (”").
<h:commandButton immediate="true" actionListener="#{bean.discardEditing}" value="#{msg.action_cancel}" />
In the example “bean.discardEditing” does some cleanup and returns a navigation outcome to navigate to the same screen again, e.g. “revertToEdit”.
To put a general error message on screen, that is shown only if errors occurred (but is not h:messages) use:
facesContext.maximumSeverity
An example:
<h:panelGroup rendered="#{! empty facesContext.maximumSeverity}"> <h:outputText styleClass="error" value="Some errors occurred." /> ... </h:panelGroup>
Avoid to mix those two up. Do NOT nest them to trigger rerendering, like this:
<a4j:commandLink ajaxSingle="true" actionListener="#{...}"> <a4j:support event="onclick" reRender="..." /> </a4j:commandLink>
It will lead to funky behaviour, sometimes sending the link, sometimes not. If you use a4j:commandLink you do not need a4j:support. Do trigger rerendering from within the commandLink.
<a4j:commandLink ajaxSingle="true" actionListener="#{...}" reRender="..." />
With facelets you can omit the h:outputText tags. Instead of
<h:outputText value="#{msg.editEmployee_name}" />
you can just write
value="#{msg.editEmployee_name}"
Reading on the web, I found a lot of approaches to use Enums with JSF. But to be honest, I found most of them quite overdone. People are working a lot with own converters, et cetera.
But on my try, it went all without that. What I did:
- just refer to the Enum type property in the bean/object
<h:outputText value="Art des Projekts" />
<h:selectOneMenu value="#{projectsBean.selectedObject.type}"
styleClass="inputfield">
<f:selectItem itemLabel="-- not assigned --" />
<f:selectItem itemLabel="------------" />
<f:selectItems value="#{optionProvider.typeOptions}" />
</h:selectOneMenu>
- and provide al list of Enum values
public final ListgetTypeOptions() { List typeOptions = new ArrayList (); for (ProjectType pt : ProjectType.values()) { typeOptions.add(new SelectItem(pt, pt.toString().toLowerCase())); } return typeOptions; }
That’s it – working without any problem.
But now I am wondering, what the reason is, why all the other people make so much effort? Did I miss something? Or is my case just to trivial?
When using message bundles with facelets first, the texts did not show.
The problem is, that you need to bring the
<f:loadBundle basename="de.your.package.messageBundle.MessageResources" var="msg" />
into the right place.
If you use it inside your .jsp, you must place it inside ><ui:define>. Or you could place it into the template file. (I prefer to place it in the template.)
After installing the rich face libs the first time, Faces Servlet threw a null pointer exception:
11.07.2009 12:18:55 org.apache.catalina.core.StandardWrapperValve invoke SCHWERWIEGEND: Servlet.service() for servlet Faces Servlet threw exception java.lang.NullPointerException at java.lang.String.startsWith(String.java:1252) at java.lang.String.startsWith(String.java:1281) at org.ajax4jsf.webapp.WebXml.getFacesResourceKey(WebXml.java:189) at org.ajax4jsf.webapp.WebXml.getFacesResourceKey(WebXml.java:222) at org.ajax4jsf.resource.InternetResourceService.serviceResource(InternetResourceService.java:139) at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:500) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:613)
This seems to happen, if you create a new dynamic web project with eclipse ganymede 3.4, because if you add jsf support with two url-mappings (e.g. *.jsf and /pages/*) to the project, eclipse creates the web.xml with the following servlet mapping:
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>
This does not work with rf. You must define the url patterns separately:
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>
This works now well for me.