Struts2文件上传实例

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struts2没有提供自己的请求解析器,也就是说,struts2不会自己去处理multipart/form-data的请求,它需要调用其他请求解析器,将HTTP请求中的表单域解析出来,但struts2在原有的上传解析器上作了进一步封装，更进一步简化了文件上传,Struts2的struts.properties配置文件中,配置struts2的上传文件解析器struts.multipart.parser=jakarta(srtuts2默认),也可以设置为常用的cos,pell等。

项目结构示意图:

web.xml文件内容:
<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" 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-app_2_5.xsd"><filter><filter-name>struts2</filter-name><filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class></filter><filter-mapping><filter-name>struts2</filter-name><url-pattern>/*</url-pattern></filter-mapping><filter><filter-name>struts-cleanup</filter-name><filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class></filter><filter-mapping><filter-name>struts-cleanup</filter-name><url-pattern>/*</url-pattern></filter-mapping> <welcome-file-list>  <welcome-file>index.jsp</welcome-file> </welcome-file-list></web-app>

这里web.xml多配置了一个ActionContextCleanUp的配置,这个类是一个filter,他的作用是方便strut2与sitemesh整合,与文件上传本没有关系,但不加载这个filter,可能在上传中出现莫名的异常,加入后就稳定了,可能是strut2的bug吧。

index.jsp文件内容:

<%@page language="java" pageEncoding="GBK"%>

<%@taglib prefix="s" uri="/struts-tags"%>

<%@taglib prefix="c" uri="http://java.sun.com/jstl/core_rt"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

 <head>

  <meta http-equiv="pragma" content="no-cache">

  <meta http-equiv="cache-control" content="no-cache">

  <meta http-equiv="expires" content="0">

 </head>

 <body>

  ${requestScope.typeError}

  <form action="upload.action" method="post"

   enctype="multipart/form-data">

   <input type="text" name="title" />

   <br>

   <input type="file" name="upload" />

   <br>

   <input value="upload" type="submit" />

  </form>

 </body>

</html>

success.jsp文件内容:
<%@ page language="java" pageEncoding="GBK"%><%@taglib prefix="s" uri="/struts-tags"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head>  <meta http-equiv="pragma" content="no-cache">  <meta http-equiv="cache-control" content="no-cache">  <meta http-equiv="expires" content="0"> </head>

 <body>

  上传成功!

  <br>

  文件标题:

  <s:property value=" + title" />

  <br>

  文件为：

  <img src="<s:property value="'upload/' + uploadFileName"/>" />

  <br>

 </body>

</html>

struts.properties文件内容:

struts.locale=zh_CN

struts.i18n.encoding=GBK

struts.multipart.parser=jakarta

struts.xml文件内容:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

 <include file="struts-default.xml" />

    <constant name="struts.multipart.maxSize" value="20971520" />

 <constant name="struts.custom.i18n.resources"

  value="globalMessages" />

 <constant name="struts.i18n.encoding" value="GBK" />

 <package name="lee" extends="struts-default">

  <action name="upload" class="lee.UploadAction">

   <param name="allowTypes">

image/pjpeg,image/bmp,image/jpg,image/png,image/gif,image/jpeg

   </param>

   <param name="savePath">/upload</param>

   <result>/success.jsp</result>

   <result name="input">/index.jsp</result>

  </action>

 </package>

</struts>

参看tomcat的web.xml中的mime:

<mime-mapping>

   <extension>gif</extension>

   <mime-type>image/gif</mime-type>

</mime-mapping>

UploadAction.java文件内容:

package lee;
import java.io.*;

import com.opensymphony.xwork2.ActionContext;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {

 private String title;

 private File upload;

 private String uploadContentType;

 private String uploadFileName;

 private String allowTypes;

 // 接受依赖注入的属性

 private String savePath;

 // 接受依赖注入的方法

 public void setSavePath(String value) {

  this.savePath = value;

 private String getSavePath() throws Exception {

  return ServletActionContext.getServletContext().getRealPath(savePath);

 public void setTitle(String title) {

  this.title = title;

 public void setUpload(File upload) {

  this.upload = upload;

 public void setUploadContentType(String uploadContentType) {

  this.uploadContentType = uploadContentType;

 public void setUploadFileName(String uploadFileName) {

  this.uploadFileName = uploadFileName;

 public String getTitle() {

  return (this.title);

 public File getUpload() {

  return (this.upload);

 public String getUploadContentType() {

  return (this.uploadContentType);

 public String getUploadFileName() {

  return (this.uploadFileName);

 @Override

 public String execute() throws Exception {

  System.out.println("开始上传单个文件---");

  System.out.println(getSavePath());

  System.out.println("==========" + getUploadFileName());

  System.out.println("==========" + getUploadContentType());

  System.out.println("==========" + getUpload());

  // 判断是否允许上传

  String filterResult = filterType(this.getAllowTypes().split(","));

  if (filterResult != null) {

   ActionContext.getContext().put("typeError","您要上传的文件类型不正确");

   return filterResult;

  // 以服务器的文件保存地址和原文件名建立上传文件输出流

  FileOutputStream fos = new FileOutputStream(getSavePath() + "\\"

    + getUploadFileName());

  FileInputStream fis = new FileInputStream(getUpload());

  byte[] buffer = new byte[1024];

  int len = 0;

  while ((len = fis.read(buffer)) > 0) {

   fos.write(buffer, 0, len);

  return SUCCESS;

 public String filterType(String[] types) {

  String fileType = this.getUploadContentType();

  for (String type : types) {

   if (type.equals(fileType)) {

    return null;

  return INPUT;

 public String getAllowTypes() {

  return allowTypes;

 public void setAllowTypes(String allowTypes) {

  this.allowTypes = allowTypes;

Struts2针对表单中名为xxx的文件域,在对应的Action类中使用3个属性来封装该文件域信息：1.类型为File的xxx属性:用来封装页面文件域对应的文件内容。2.类型为String的xxxFileName属性:用来封装该文件域对应的文件的文件名。3.类型为String的xxxContentType属性:用来封装该文件域应用的文件的文件类型。

以上程序调试通过！