‘初学’文件下载

文件下载

1.准备页面index.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%>">

  </head>
  
  <body>
    <a href="download.action?fileName=12092-106.j31pg">点击此处下载文档</a>
  </body>
</html>

 2.struts.xml中

<?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>
	<!-- 动态方法调用 -->
 
    <constant name="struts.devMode" value="false" />
    
    
    <package name="default" namespace="/" extends="struts-default">
    	
        <action name="download" class="cn.happy.action.FileDownAction" method="execute">
        	<param name="inputPath">/image</param>
        	
           <result name="success" type="stream">
           	<param name="contentType">application/octet-stream</param>
           	<param name="inputName">inputStream</param>
           	<param name="ContentDisposition">
           		attachment;filename="${fileName}"
           	</param>
           <param name="bufferSize">4096</param>
           </result>
        </action>
    </package>
</struts>

 3.web.xml中

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <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.java类

package cn.happy.action;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class FileDownAction extends ActionSupport {
         //读取下载文件的目录
	private String inputPath;
	//下载文件的文件名
	private String fileName;
	//读取下载文件的输入流
	@SuppressWarnings("unused")
	private InputStream inputStream;
	//下载文件类型
	private String conentType;
	
	@Override
	public String execute() throws Exception {
		return SUCCESS;
				
	}
	
	//创建inputStream输入流 
		public InputStream getInputStream() throws FileNotFoundException {
			String path=ServletActionContext.getServletContext().getRealPath(inputPath);
			return new BufferedInputStream(new FileInputStream(path+"\"+fileName));
		}
	public void setInputStream(InputStream inputStream) {
		this.inputStream = inputStream;
	}
	
	
	public String getInputPath() {
		return inputPath;
	}
	public void setInputPath(String inputPath) {
		this.inputPath = inputPath;
	}
	public String getFileName() {
		return fileName;
	}
	public void setFileName(String fileName) {
		this.fileName = fileName;
	}
	public String getConentType() {
		return conentType;
	}
	public void setConentType(String conentType) {
		this.conentType = conentType;
	}
	
}

  再给你们配张图

原文地址:https://www.cnblogs.com/yangronglin/p/5945287.html