java - 上传文件的 fileUpload 和 primefaces null 值

Question

我是 primefaces 的新手，我正在尝试在我的项目中实现 fileUpload 组件。 我已经打开了文档，但我不清楚并且我的实现不起作用。

文档的第一行说:

“首先要做的是配置解析多部分请求的文件上传过滤器。文件上传过滤器应映射到 Faces Servlet。”

建议放置此代码:

<filter>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<filter-class>
org.primefaces.webapp.filter.FileUploadFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>PrimeFaces FileUpload Filter</filter-name>
<servlet-name>Faces Servlet</servlet-name>
</filter-mapping>

进入 web.xml 描述符

第一个问题: “...解析多部分请求的过滤器”。我明白这意味着如果我想上传超过 1 个文件，我应该使用该代码(我不确定)。 所以我想我应该错过这一点，但是在我在互联网上找到的大多数示例中，应该实现此代码。

第二个问题: 当我尝试在 web.xml 文件中实现过滤器时:

<?xml version="1.0" encoding="ISO-8859-1"?>
<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_2_5.xsd"
version="2.5">

<display-name>Archetype Created Web Application</display-name>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/classes/configuration-context.xml</param-value>
</context-param>

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

<filter>
    <filter-name>springSecurityFilterChain</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
    <filter-name>springSecurityFilterChain</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>INCLUDE</dispatcher>
    <dispatcher>ERROR</dispatcher>
</filter-mapping>

<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>org.primefaces.webapp.filter.FileUploadFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>

<listener>
    <listener- class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>


<!-- JSF Mapping -->
<servlet>
    <servlet-name>facesServlet</servlet-name>
    <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>facesServlet</servlet-name>
    <url-pattern>*.jsf</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>facesServlet</servlet-name>
    <url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>facesServlet</servlet-name>
    <url-pattern>*.faces</url-pattern>
</servlet-mapping>

<context-param>
    <param-name>javax.faces.PROJECT_STAGE</param-name>
    <param-value>Development</param-value>
</context-param>
<context-param>
    <param-name>javax.faces.DEFAULT_SUFFIX</param-name>
    <param-value>.xhtml</param-value>
</context-param>
<context-param>
    <param-name>primefaces.THEME</param-name>
    <param-value>redmond</param-value>
</context-param>

</web-app>

我收到很多错误:

java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component     [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/wals]]
at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component     [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/wals]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 7 more
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.getDeclaredFields(Unknown Source)
at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:261)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationFilterAnnotations(WebAnnotationSet.java:110)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:66)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:405)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:881)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:369)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5269)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
... 21 more

第三个问题: 这可能是由第一个问题和第二个问题引起的，但我不确定。如果我放弃过滤器代码并像 xhtml 文件中那样实现 primefaces:

<h:form enctype="multipart/form-data">
<h:outputText value="Wybór zdjęcia: " />
<p:fileUpload value="#{fileUploadController.file}" mode="simple" />
<p:commandButton value="Submit" ajax="false"/>
</h:form>

其中简单定义了 fileUploadController bean:

@Component
@Scope("session")
@ManagedBean
@SessionScoped
public class FileUploadController
{  
private UploadedFile file;

public UploadedFile getFile()
{
    return file;
}

public void setFile(UploadedFile file)
{
    this.file = file;
}
}

我得到文件字段的空值。我的目标是上传图像，将其更改为 Blob 并发送到数据库。 我将非常感谢您的帮助，因为没有那部分我就无法继续我的项目。

Answer 1

看起来您可能缺少一些依赖项。在另一个线程上也有类似的错误，我已发布链接 here为你。它基本上表明您需要添加 commons-fileupload 和 commons-io 的 jar 文件。希望这可以帮助您解决问题。