Richfaces 文件上传错误

Question

我尝试使用rich:fileupload componenet 上传文件。当我尝试上传文件时，出现错误， 错误是

Aug 24, 2011 9:41:19 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet Faces Servlet threw exception
java.lang.NullPointerException
        at org.richfaces.renderkit.FileUploadRendererBase.doDecode(FileUploadRendererBase.java:140)
        at org.ajax4jsf.renderkit.RendererBase.decode(RendererBase.java:75)
        at javax.faces.component.UIComponentBase.decode(UIComponentBase.java:764)
        at javax.faces.component.UIInput.decode(UIInput.java:719)
        at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1006)
        at javax.faces.component.UIInput.processDecodes(UIInput.java:633)
        at javax.faces.component.UIForm.processDecodes(UIForm.java:203)
        at org.ajax4jsf.component.AjaxViewRoot$1.invokeContextCallback(AjaxViewRoot.java:392)
        at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:238)
        at org.ajax4jsf.component.AjaxViewRoot.processDecodes(AjaxViewRoot.java:409)
        at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:101)
        at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
        at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
        at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
        at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:365)
        at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:495)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:341)
        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:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        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:298)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
        at java.lang.Thread.run(Thread.java:679)

请帮我解决这个问题。

Answer 1

堆栈跟踪提示您同时使用 RichFaces 3.3 和 Tomahawk 1.x。两个组件库都提供文件上传组件，并使用特殊的Filter 从请求正文中提取上传的文件。堆栈跟踪显示 Tomahawk 正在解析请求正文 在 RichFaces 之前。

at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:365)
...
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:341)

请求正文一旦被解析，就不能再被解析。因此，RichFaces 无法从请求正文中提取上传的文件。你所面临的NullPointerException 只是这个无法预料的后果（RichFaces 的家伙应该抛出一个更明确的异常，比如IllegalStateException 带有消息“请求正文中缺少上传的文件”或类似，但阿拉）。

如果您想使用 RichFaces 文件上传功能，那么您真的必须从 web.xml 中删除 Tomahawk 的 ExtensionsFilter。您只会错过<t:inputFileUpload> 功能和特定外观组件的一些次要功能（脚本/样式表）。其他 Tomahawk 组件应该可以正常工作。

Answer 2

RichFaces 3.3 文件上传工作正常 按照这个步骤。

Add this in your page:

<rich:fileUpload id="fileupload" addControlLabel="Browse" required="true"
fileUploadListener="#{ demoForm.listener}" acceptedTypes="xml"
ontyperejected="alert('Only xml files are accepted');"
maxFilesQuantity="1" listHeight="57px" listWidth="100%" disabled="#{demoForm.disabled}" >
<a4j:support event="onclear" action="#{ demoForm.clearUploadData}" reRender="fileupload" />
</rich:fileUpload>

FormBean：

/**
*
* @param event
* @throws Exception
*/
public void listener(UploadEvent event) throws Exception{
UploadItem item = event.getUploadItem();
FileUpload file = new FileUpload();
file.setLength(item.getData().length);
file.setFile(item.getData());
file.setName(item.getFileName());
files.add(file);
}


/**
 * 
 * @return
 */public String clearUploadData() {
files.clear();
setUploadsAvailable(1);
return null;
}

在 web.xml 中添加此内容

<!-- Richfaces  fileupload-->
    <filter>
        <!-- Parameters used by rich file upload -->
        <init-param>
            <param-name>createTempFiles</param-name>
            <param-value>false</param-value>
        </init-param>
        <!-- configurable property of rich:fileUpload to set maximum allowed file size, currently set to  200MB -->
        <init-param>
            <param-name>maxRequestSize</param-name>
            <param-value>209715200</param-value>
        </init-param>
        <init-param>
            <param-name>forceparser</param-name>
            <param-value>false</param-value>
        </init-param>
    </filter>