使用Struts2实现文件的上传和下载

(一)单个文件的上传步骤:

1.拷贝jar包:commons-fileupload.jar, commons-io.jar

下载链接(文件上传.rar):http://www.cnblogs.com/withyou/admin/Files.aspx

2.JSP页面中增加form:(form属性是固定的)

<form action= "uploadAction"    enctype="multipart/form-data" method="post"  >
      姓名：<input type="text" name="uname"  /><br/>
       附件：<input type="file" name="fileUpload"  /><br/>           
               <input type="submit"  value="提交" />
</form>

3.action层代码:

 1 public class UploadAction {
 2     private String uname;
 3     private  File fileUpload;
 4     private String   fileUploadFileName;//名字规范  File属性的 名字+FileName,(该属性为上传过来的文件名)
 5     public String execute() throws IOException{
 6         String path = ServletActionContext.getServletContext().getRealPath("/fileUpload/");//该path为tomcat下的webapp/工程/下
 7         for(int i = 0;i<fileUpload.length;i++){
 8             String[] fielNameArray = fileUploadFileName[i].split("\.");
 9             //将上传的文件存到指定路径下,UUID是为了避免文件名重复
10             FileUtils.copyFile(fileUpload[i],new File(path+"\"+UUID.randomUUID()+"."+fielNameArray[fielNameArray.length-1]));            
11         }
12         return null;
13     }
14     public String getUname() {
15         return uname;
16     }
17 
18     public void setUname(String uname) {
19         this.uname = uname;
20     }
21 
22     public File[] getFileUpload() {
23         return fileUpload;
24     }
25 
26     public void setFileUpload(File[] fileUpload) {
27         this.fileUpload = fileUpload;
28     }
29 
30     public String[] getFileUploadFileName() {
31         return fileUploadFileName;
32     }
33 
34     public void setFileUploadFileName(String[] fileUploadFileName) {
35         this.fileUploadFileName = fileUploadFileName;
36     }
37 }

4.补充几个java获取路径的信息
　　a.获取web服务器下的文件路径 (tomcat等服务器安装目录/webapp/工程/)
　　　　request.getRealPath("/") ;application.getRealPath("")【jsp中】 ;ServletContext().getRealPath("")

　　　　如:request.getRealPath("web.xml") 的结果为:
　　　　C:Program FilesApache Software FoundationTomcat 5.5webappsstrutsTestweb.xml

　　b.获取本地路径

　　　　this.getClass().getClassLoader().getResource("").getPath(); ＝＝/D:/workspace/strutsTest/WebRoot/WEB-INF/classes/
　　　　this.getClass().getResource("").getPath().toString(); ＝＝/D:/workspace/strutsTest/WebRoot/WEB-INF/classes/bl/

　　c.获取相对路径 :

　　　　request.getContextPath();

(二)多个文件上传步骤:

　1.拷贝jar包;

　2.jsp代码如下:

 1 <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6 
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">   
11     <title>My JSP 'upload.jsp' starting page</title>
12     <script src="js/jquery-1.4.4.js"></script>
13     <script type="text/javascript">
14             /*添加附件*/
15             function addFileButton(){
16                 var fileStr = "<div>附件：<input type='file'  name='fileUpload' />  <input type='button' value='删除' onclick='delFileButton(this);' /><br/></div>";
17                 $("#div1").append(fileStr);
18             }
19             /*删除附件*/
20             function delFileButton(obj){
21                 obj.parentNode.parentNode.removeChild(obj.parentNode);
22             }
23     </script>
24   </head>
25   <body>
26            <form action= "uploadAction"    enctype="multipart/form-data"  method="post"  >
27                姓名：<input type="text" name="uname"  /><br/>
28                <fieldset>
29                    <legend><input type="button"  value="添加附件"  onclick="addFileButton();" /></legend>
30                    <div  id="div1">
31                        <div>附件：<input type="file" name="fileUpload"  /><input type="button" value="删除" onclick="delFileButton(this);" /><br/></div>
32                    </div>
33                </fieldset>
34                <input type="submit"  value="提交" />
35            </form>
36   </body>
37 </html>

View Code

　3.action层代码:

 1 package com.bjsxt.struts2.action;
 2 
 3 import java.io.File;
 4 import java.io.IOException;
 5 import java.util.UUID;
 6 
 7 import org.apache.commons.io.FileUtils;
 8 import org.apache.struts2.ServletActionContext;
 9 
10 public class UploadAction {
11     private String uname;
12     private  File[] fileUpload;
13     private String[]   fileUploadFileName;//名字规范  File属性的 名字+FileName;
14     public String execute() throws IOException{
15         System.out.println("--------uname-------"+uname);
16         String path = ServletActionContext.getServletContext().getRealPath("/fileUpload/");
17         System.out.println(path);
18         for(int i = 0;i<fileUpload.length;i++){
19             String[] fielNameArray = fileUploadFileName[i].split("\.");
20             FileUtils.copyFile(fileUpload[i],new File(path+"\"+UUID.randomUUID()+"."+fielNameArray[fielNameArray.length-1]));            
21         }
22         return null;
23     }
24     public String getUname() {
25         return uname;
26     }
27 
28     public void setUname(String uname) {
29         this.uname = uname;
30     }
31 
32     public File[] getFileUpload() {
33         return fileUpload;
34     }
35 
36     public void setFileUpload(File[] fileUpload) {
37         this.fileUpload = fileUpload;
38     }
39 
40     public String[] getFileUploadFileName() {
41         return fileUploadFileName;
42     }
43 
44     public void setFileUploadFileName(String[] fileUploadFileName) {
45         this.fileUploadFileName = fileUploadFileName;
46     }
47 }

View Code

(三)文件下载:

1.action层代码:

 1 package com.bjsxt.hib.action;
 2 
 3 import java.io.File;
 4 import java.io.FileInputStream;
 5 import java.io.FileNotFoundException;
 6 import java.io.InputStream;
 7 import java.io.UnsupportedEncodingException;
 8 
 9 public class DownloadAction {
10     private InputStream inputStream;
11     private String fileName;
12     
13     public String execute(){
14         try {
15             this.inputStream = new FileInputStream("D:\123.txt");//这里有很多处理手段满足不同需求(从数据库读取等)
16             this.fileName = "哈喽.txt";
17         } catch (FileNotFoundException e) {
18             e.printStackTrace();
19         }
20         return "success";
21     }
22     public InputStream getInputStream() {
23         return inputStream;
24     }
25     public void setInputStream(InputStream inputStream) {
26         this.inputStream = inputStream;
27     }
28     /*乱码处理*/
29     public String getFileName() {
30         String temp=null;
31         try {
32             temp = new String(this.fileName.getBytes(),"ISO-8859-1");
33         } catch (UnsupportedEncodingException e) {
34             e.printStackTrace();
35         }
36         return temp;
37     }
38     public void setFileName(String fileName) {
39         this.fileName = fileName;
40     }
41     
42 }

2.struts.xml配置:

1  <action name="downloadAction" class="com.bjsxt.hib.action.DownloadAction">
2             <result name="success" type="stream">
3                 <!--前两行是不可变的 -->
4                 <param name="contentType">application/x-download</param>
5                 <param name="inputName">inputStream</param>
6                 <param name="contentDisposition">attachment;filename="${fileName}"</param>
7                 <param name="bufferSize">4096</param>
8             </result>
9 </action>

3.浏览器直接输入:http://localhost:8080/downloadAction即可访问,下载.

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原文地址：https://www.cnblogs.com/withyou/p/3178843.html