java下载文件代码
2015-08-29 21:37
337 查看
1.servlet下载类
java代码
2.下面jsp页面代码
html代码
运行代码
3.这是web.xml配置文件
xml代码
java代码
import javax.servlet.*; import javax.servlet.http.*; import java.io.*; import java.util.*; public class FileDownServlet extends HttpServlet { private static final String CONTENT_TYPE = "text/html; charset=GBK"; //Initialize global variables public void init() throws ServletException { } //Process the HTTP Get request public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType(CONTENT_TYPE); //得到下载文件的名字 //String filename=request.getParameter("filename"); //解决中文乱码问题 String filename=new String(request.getParameter("filename").getBytes("iso-8859-1"),"gbk"); //创建file对象 File file=new File("F://book//WebRoot//"+filename); //设置response的编码方式 response.setContentType("application/x-msdownload"); //写明要下载的文件的大小 response.setContentLength((int)file.length()); //设置附加文件名 // response.setHeader("Content-Disposition","attachment;filename="+filename); //解决中文乱码 response.setHeader("Content-Disposition","attachment;filename="+new String (filename.getBytes("gbk"),"iso-8859-1")); //读出文件到i/o流 FileInputStream fis=new FileInputStream(file); BufferedInputStream buff=new BufferedInputStream(fis); byte [] b=new byte[1024];//相当于我们的缓存 long k=0;//该值用于计算当前实际下载了多少字节 //从response对象中得到输出流,准备下载 OutputStream myout=response.getOutputStream(); //开始循环下载 while(k<file.length()){ int j=buff.read(b,0,1024); k+=j; //将b中的数据写到客户端的内存 myout.write(b,0,j); } //将文件数据刷新到用户名电脑上 myout.flush(); } //Process the HTTP Post request public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } //Clean up resources public void destroy() { } }
2.下面jsp页面代码
html代码
运行代码
<%@ page language="java" import="java.util.*,com.message.*" pageEncoding="gbk"%> <jsp:directive.page import="com.MessageBean;"/> <% 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 'book.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> <!-- <a href="java.rar">5.1下载书--java</a> <br>--> <% //Vector vv=(Vector)session.getAttribute("message"); //for(int i=0;i<vv.size();i++){ // MessagesBean mb=(MessagesBean)vv.get(i); // out.println("<tr>"); // out.println("<td>"+mb.getSender()+"</td>"); // out.println("<td>"+mb.getMess_time()+"</td>"); // out.println("<td>"+mb.getGeter()+"</td>"); // out.println("<td>"+mb.getMess_content()+"</td>"); String filename=null; session.setAttribute("java.rar",filename); //取得文件名 // filename=getFilepath().substring(mb.getFilepath().lastIndexOf("/")+1); out.println("<td><a href=FileDownServlet?filename=java.rar>5.1下载书--java</a></td>");//java.rar这个可以改成变量 out.println("<td><a href=FileDownServlet?filename=dos.rar>dos视频教程</a></td>"); out.println("<td><a href=FileDownServlet?filename=常用DOS命令.rar>常用DOS命令</a></td>"); out.println("</tr>"); // } %> </body> </html>
3.这是web.xml配置文件
xml代码
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>FileDownServlet</servlet-name> <servlet-class>com.message.FileDownServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>FileDownServlet</servlet-name> <url-pattern>/FileDownServlet</url-pattern> </servlet-mapping> </web-app>
相关文章推荐
- JVM内存区域划分Eden Space、Survivor Space、Tenured Gen,Perm Gen解释
- eclipse在资源管理器中打开文件
- 初识JAVA5(线程)
- Spring框架简介和初次框架配置
- Spring笔记——Spring框架简介和初次框架配置
- 初识JAVA4(抽象类、接口、多态)
- java按指定编码写入和读取文件内容的类
- Struts1.x 总结(很全面)
- 初识JAVA3(重载、单子模式)
- Java中的异常(2)
- 用Eclipse 开发Dynamic Web Project应用程序 【转】
- Java中的异常(1)
- java基础笔记
- 初识JAVA2(数组、类、对象、构造器)
- 【JAVA】.jar与sources.jar浅谈~~么么哒
- Spring 容器(一)
- Struts面试题
- Struts面试题
- 详解Java中格式化输出浮点数
- Java中instanceof关键字的应用