使用struts2实现上传下载功能（附代码）。类似于ftp服务器。不止局限于本机的上传下载，其他机器也可使用此功能，服务器似的功能

来源：互联网发布：java 301跳转编辑：程序博客网时间：2024/06/03 17:33

一、截图展示功能概要：

（1）主界面：

（2）单击浏览后：

（3）选择文件，单击提交，进入文件展示界面（下载功能界面）

（4）单击“下载”按钮，

（5）单击保存进行保存，成功保存

功能展示完毕。

二、代码实现：

1.目录结构

2.struts2.xml

<?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>        <!-- struts的开发模式，设置为true,改变此文档中的配置不用重启tomcat -->        <constant name="struts.devMode" value="true"></constant>        <package name="default" extends="struts-default">            <default-action-ref name="index" />            <action name="index"><result>/jsp/upload.jsp</result></action>        </package>        <package name="uploadAnddownload" extends="struts-default" namespace="/user">            <result-types>   <!-- 用于处理下载文件,提示对话框点击取消时报出异常问题 -->   <result-type name="streamx" class="com.sunspoter.lib.web.struts2.dispatcher.StreamResultX"></result-type></result-types>            <action name="upload" class="com.upload.action.UploadAction" method="upload">                <result name="input">/jsp/listfile.jsp</result>    <result name="success" type="redirectAction">queryAllFile</result>            </action>            <action name="queryAllFile" class="com.upload.action.QueryAllFileAction" method="queryAllFile">                <result name="input">/jsp/listfile.jsp</result>            </action>            <action name="download" class="com.upload.action.DownloadAction" method="download">            <result type="streamx">                  <!-- 文件类型 —— application/octet-stream 表示无限制 -->                  <param name="contentType">application/octet-stream;charset=ISO8859-1</param>                  <!-- 流对象名 —— 去找Action中的getInputStream方法 -->                  <param name="inputName">inputStream</param>                  <!-- 文件名 —— 将调用该Action中的getDownloadFileName方法 -->                  <param name="contentDisposition">attachment;fileName="${downloadFileName}"</param>                  <!-- <param name="bufferSize">4096</param>   -->            </result>              </action>        </package>    </struts>

3.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/j2ee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">  <filter>    <filter-name>struts2</filter-name>    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>  </filter>  <filter-mapping>    <filter-name>struts2</filter-name>    <url-pattern>/*</url-pattern>  </filter-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>

4.index.jsp

<% response.sendRedirect("index.action"); %>

5.upload.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"  pageEncoding="utf-8"%><%@ taglib prefix="s" uri="/struts-tags" %><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'upload.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--><script type="text/javascript">/*     function showPhoto(){       document.getElementById("showPhoto").src=document.getElementById("photo").value;    } */</script>  </head>    <body>      <form action="user/upload.action" method="post" enctype="multipart/form-data">         <input type="file" name="photo" id="photo" onchange="showPhoto()"/>         <input type="submit" value="提交"/>      </form>      <br>       <s:a action="queryAllFile.action" namespace="/user">                                    进入下载页面       </s:a><!--       <div>          <img id="showPhoto" src="/upload/photo.jpg"  style="width:160px;height:120px;"/>      </div> -->  </body></html>

6.listfile.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%@ taglib prefix="s" uri="/struts-tags"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'listfile.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>    <body>           文件列表<br>       <table border="1">   <s:iterator id="file" value="fileNameMap">             <tr>            <td>${file.value}</td>            <td>              <s:a action="download.action" namespace="/user">                 <s:param name="fileName">${file.value}</s:param> 下载              </s:a>            </td> </tr>    </s:iterator>  </table>   </body></html>

7.UploadAction

package com.upload.action;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;import org.apache.commons.io.IOUtils;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class UploadAction extends ActionSupport{private static final long serialVersionUID = 1L;private File photo;private String photoFileName;private String photoContentType;private String savePath;public String upload(){System.out.println("**********************upload*********************");//判断目录是否存在，不存在的话要新建File file = new File(getSavePath());if(!file.exists() && !file.isDirectory()){System.out.println(savePath+"目录不存在，需要重建");file.mkdir();}if(photo!=null){try {InputStream is = new FileInputStream(getPhoto());OutputStream os = new FileOutputStream(getSavePath()+"//"+getPhotoFileName());IOUtils.copy(is, os);os.flush();IOUtils.closeQuietly(is);IOUtils.closeQuietly(os);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}return "success";}public File getPhoto() {return photo;}public void setPhoto(File photo) {this.photo = photo;}public String getPhotoFileName() {return photoFileName;}public void setPhotoFileName(String photoFileName) {this.photoFileName = photoFileName;}public String getPhotoContentType() {return photoContentType;}public void setPhotoContentType(String photoContentType) {this.photoContentType = photoContentType;}public String getSavePath() {return ServletActionContext.getServletContext().getRealPath("/upload");}public void setSavePath(String savePath) {this.savePath = savePath;}}

8.DownloadAction

package com.upload.action;import java.io.InputStream;import java.io.UnsupportedEncodingException;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class DownloadAction extends ActionSupport{private static final long serialVersionUID = 1L;private String fileName;//要下载的文件名      private InputStream inputStream;        public String download() throws Exception {      System.out.println("********************download****************");System.out.println("getFileName="+getFileName());        inputStream = ServletActionContext.getServletContext().getResourceAsStream("/upload/" + getFileName()); System.out.println("inputStream="+inputStream);        return SUCCESS;      }      //为解决文件名字乱码。struts2.xml中读取的是downloadFileName而不是fileName    public String getDownloadFileName() throws UnsupportedEncodingException {           String downloadFileName = new String(fileName.getBytes(), "ISO8859-1");           return downloadFileName;         }       public String getFileName() {          return fileName;      }        public void setFileName(String fileName) throws UnsupportedEncodingException {          //this.fileName = fileName;           this.fileName = new String(fileName.getBytes("ISO-8859-1"),"UTF-8");    }        public InputStream getInputStream() {          return inputStream;      }        public void setInputStream(InputStream inputStream) {          this.inputStream = inputStream;      }  }

9.QueryAllFileAction

package com.upload.action;import java.io.File;import java.util.HashMap;import java.util.Map;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class QueryAllFileAction extends ActionSupport{/** *  */private static final long serialVersionUID = 1L;private Map<String,String> fileNameMap;public String queryAllFile(){System.out.println("******************queryAllFile******************");//获取上传文件的目录String filePath = ServletActionContext.getServletContext().getRealPath("/upload");//存储要下载的文件名fileNameMap = new HashMap<String,String>();//递归遍历filePath下目录下的所有文件和目录，将文件的文件名存储到map集合中listFile(new File(filePath),fileNameMap);System.out.println("fileNameMap="+fileNameMap);return "input";}    //file即代表一个文件，也代表一个文件目录;map存储文件名的集合。递归遍历指定目录下的所有文件private void listFile(File file, Map<String, String> map) {//如果file代表的不是一个文件，而是一个目录if(!file.isFile()){//列出该目录下的所有文件和目录File files[] = file.listFiles();for(File f : files){//递归listFile(f,map);}}else{map.put(file.getName(), file.getName());}}public Map<String, String> getFileNameMap() {return fileNameMap;}public void setFileNameMap(Map<String, String> fileNameMap) {this.fileNameMap = fileNameMap;}}

三、小小心得

（1）做上传功能之前一直纠结：文件是怎么传输到后台的，经过几天的寻找各种资源。明白前台<form action="user/upload.action" method="post" enctype="multipart/form-data">中<input type="file" name="photo">经过jsp解析（enctype="multipart/form-data"是允许将type=file的input解析成流的形式）。后台action中属性：

private File photo;
private String photoFileName;
private String photoContentType;

与jsp中<input type="file" name="photo">对应

（2）下载功能中其实重要的就是struts中的配置，将后台传输过来的文件形成的流和文件名字进行配置，输出到jsp前台

需要注意的是：<param name="contentDisposition">attachment;fileName="${downloadFileName}"</param> 是为了解决中文乱码。附件代码以及上边的粘贴代码中都有注释我就不多解释；

（3）其余的我就不多说了。只要对struts2的基本流程了解。把下边链接中的代码copy到自己的电脑上研究运行。我相信肯定能更加清楚其中原理。

四、完整项目包链接

http://download.csdn.net/detail/zhaoxiaoyueyue/9482979

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