我已经在这篇文章中修复了一些其他问题（fileuploadhandler 现在正在工作），我的代码如下：
Bean:
@ManagedBean
@ViewScoped
public class TempBean implements Serializable{
private static final long serialVersionUID = -70753689043016662L;
private List<String> names; //to remember which files have been uploaded
public void load(){
System.out.println("@prerender");
}
public TempBean() {
super();
System.out.println("@constructor");
names = new ArrayList<String>();
}
@PostConstruct
public void pc(){
System.out.println("@postconstruct");
}
public void handleFileUpload(FileUploadEvent event) {
String filename = event.getFile().getFileName();
System.out.println("INCOMING FILE: " + filename);
names.add(filename);
if(!names.isEmpty()){
System.out.println("Files uploaded:");
for(String n : names){
System.out.println("# " + n);
}
System.out.println();
}
}
public List<String> getNames() {
return names;
}
public void setNames(List<String> names) {
this.names = names;
}
}
xhtml 页面：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui" >
<h:head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</h:head>
<f:event type="preRenderView" listener="#{tempBean.load}" />
<h:body>
<h:form>
<p:fileUpload
fileUploadListener="#{tempBean.handleFileUpload}"
mode="advanced" dragDropSupport="true" multiple="true" update=":overview" />
</h:form>
<h:panelGroup id="overview">
<ui:repeat var="file" value="#{tempBean.names}">
#{file} <br/>
</ui:repeat>
</h:panelGroup>
</h:body>
</html>
我现在面临的问题（或者我提出一个新问题的原因）是，当我上传多个（例如三个）文件时，只有其中一个被附加到空列表中。当我重新上传剩余的两个文件时，只有其中一个被附加到列表中。
有趣的是，为每个文件调用handleFileUpload(...)...
这是我同时上传三个文件时的控制台输出：
@constructor
@postconstruct
@prerender
INCOMING FILE: test1.jpe
INCOMING FILE: test3.jpe
Files uploaded:
INCOMING FILE: test2.jpe
# test3.jpe
-END OF LIST-
Files uploaded:
# test1.jpe
Files uploaded:
# test2.jpe
-END OF LIST-
-END OF LIST-
@prerender
@prerender
@prerender
我该怎么做才能使文件上传组件正常运行？这是一个错误还是 ajax 问题？
这是我的 web.xml：
<?xml version="1.0" encoding="UTF-8"?>
<web-app
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0" >
<display-name>TestProjekt</display-name>
<welcome-file-list>
<welcome-file>test.xhtml</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<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>
<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>*.xhtml</url-pattern>
</servlet-mapping>
<context-param>
<param-name>javax.servlet.jsp.jstl.fmt.localizationContext</param-name>
<param-value>resources.application</param-value>
</context-param>
<context-param>
<description>State saving method: 'client' or 'server' (=default). See JSF Specification 2.5.2</description>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
<context-param>
<param-name>facelets.SKIP_COMMENTS</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>primefaces.UPLOADER</param-name>
<param-value>commons</param-value>
</context-param>
<context-param>
<description>
This parameter tells MyFaces if javascript code should be allowed in
the rendered HTML output.
If javascript is allowed, command_link anchors will have javascript code
that submits the corresponding form.
If javascript is not allowed, the state saving info and nested parameters
will be added as url parameters.
Default is 'true'</description>
<param-name>org.apache.myfaces.ALLOW_JAVASCRIPT</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<description>
If true, rendered HTML code will be formatted, so that it is 'human-readable'
i.e. additional line separators and whitespace will be written, that do not
influence the HTML code.
Default is 'true'</description>
<param-name>org.apache.myfaces.PRETTY_HTML</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.DETECT_JAVASCRIPT</param-name>
<param-value>false</param-value>
</context-param>
<context-param>
<description>
If true, a javascript function will be rendered that is able to restore the
former vertical scroll on every request. Convenient feature if you have pages
with long lists and you do not want the browser page to always jump to the top
if you trigger a link or button action that stays on the same page.
Default is 'false'
</description>
<param-name>org.apache.myfaces.AUTO_SCROLL</param-name>
<param-value>true</param-value>
</context-param>
<filter>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
<init-param>
<param-name>uploadDirectory</param-name>
<param-value>C:\tmp</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<servlet-name>Faces Servlet</servlet-name>
</filter-mapping>
</web-app>
和我的 faces.config：
<?xml version="1.0" encoding="UTF-8"?>
<faces-config
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"
version="2.0">
</faces-config>
