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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

2016-04-10 21:10 1056 查看

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

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<?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>
        
        <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>
        &
4000
lt;package name="uploadAnddownload" extends="struts-default" namespace="/user">
            <result-types>
               
               <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">
                    
                    <param name="contentType">application/octet-stream;charset=ISO8859-1</param>
                    
                    <param name="inputName">inputStream</param>
                    
                    <param name="contentDisposition">attachment;fileName="${downloadFileName}"</param>
                    
                </result>
            </action>
        </package>
    </struts>

3.web.xml

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<?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

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

5.upload.jsp

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<%@ 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"
17a1a
>
<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">
    
    <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>

  </body>
</html>

6.listfile.jsp

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<%@ 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">
    

  </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

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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 block
                e.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

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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

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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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