Struts2文件下载
文件下载是一个很常见的功能,用struts2实现文件下载的步骤:
一)定义一个Action类,FileDownload.Java
- package com.struts2.filedownload;
- import java.io.InputStream;
- import org.apache.struts2.ServletActionContext;
- import com.opensymphony.xwork2.ActionSupport;
- //文件下载
- public class FileDownload extends ActionSupport{
- private int number ;
- private String fileName;
- public int getNumber() {
- return number;
- }
- public void setNumber(int number) {
- this.number = number;
- }
- public String getFileName() {
- return fileName;
- }
- public void setFileName(String fileName) {
- this.fileName = fileName;
- }
- //返回一个输入流,作为一个客户端来说是一个输入流,但对于服务器端是一个 输出流
- public InputStream getDownloadFile() throws Exception
- {
- if(1 == number)
- {
- this.fileName = "Dream.jpg" ;
- //获取资源路径
- return ServletActionContext.getServletContext().getResourceAsStream("upload/Dream.jpg") ;
- }
- else if(2 == number)
- {
- this.fileName = "jd2chm源码生成chm格式文档.rar" ;
- //解解乱码
- this.fileName = new String(this.fileName.getBytes("GBK"),"ISO-8859-1");
- return ServletActionContext.getServletContext().getResourceAsStream("upload/jd2chm源码生成chm格式文档.rar") ;
- }
- else
- return null ;
- }
- @Override
- public String execute() throws Exception {
- return SUCCESS;
- }
- }
二)在struts.xml文件中配置相关信息
- <struts>
- <package name="struts2" extends="struts-default">
- <action name="FileDownload" class="com.struts2.filedownload.FileDownload">
- <result name="success" type="stream">
- <param name="contentType">text/plain</param>
- <param name="contentDisposition">attachment;fileName="${fileName}"</param>
- <param name="inputName">downloadFile</param>
- <param name="bufferSize">1024</param>
- </result>
- </action>
- </package>
- </struts>
1.结果类型必须要写成 type="stream" ,与之对应的处理类是 org.apache.struts2.dispatcher.StreamResult
2.涉及到的参数:
3.
1) <param name="contentDisposition">attachment;fileName="${fileName}"</param>
contentDisposition默认是 inline(内联的), 比如说下载的文件是文本类型的,就直接在网页上打开,不能直接打开的才会打开下载框自己选择
2) attachment :下载时会打开下载框
3) fileName="${fileName}" :在这定义的名字是一个动态的,该名字是显示在下载框上的文件名字
4.<param name="inputName">downloadFile</param>,这个downloadFile名字要和FileDownload.java类中的getDownloadFile()方法名去掉get 一致
三)用于显示下载的链接界面 filedownload.jsp
- <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
- <%
- 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 'filedownload.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>
- <h2>文件下载内容:</h2><br/>
- Dream.jpg:<a href="FileDownload.action?number=1">点击下载</a><br/>
- jd2chm源码生成chm格式文档.rar:<a href="FileDownload.action?number=2">点击下载2</a>
- </body>
- </html>
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