struts2实现文件下载功能
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%>" rel="external nofollow" > <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" rel="external nofollow" > --> </head> <body> <h2>文件下载内容:</h2><br/> Dream.jpg:<a href="FileDownload.action?number=1" rel="external nofollow" >点击下载</a><br/> jd2chm源码生成chm格式文档.rar:<a href="FileDownload.action?number=2" rel="external nofollow" >点击下载2</a> </body> </html>
文件上传链接:
1)Servlet 文件上传: 点击打开链接
2)Struts2 文件上传:点击打开链接
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