本文實例為大家分享了servlet下載文件的具體代碼，供大家參考，具體內容如下
1.servlet下載文件
servlet下載文件就是將服務器端的文件傳輸到客戶端。
2案例
下載文件servlet類
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package com.learn;import javax.servlet.ServletConfig;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;/** * Created by Administrator on 2017/09/24. */public class DownLoadServlet extends HttpServlet { private String filePath; @Override public void init(ServletConfig config) throws ServletException { super.init(config); filePath = config.getInitParameter("filePath"); //初始化路徑 //filePath = config.getServletContext().getRealPath(filePath); System.out.println("初始化文件路徑："+filePath); } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doPost(req,resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { OutputStream out; //輸出流 InputStream in; //輸入流 String fileName = req.getParameter("fileName"); System.out.println("文件名稱："+fileName); //如果把文件名為null則提示用戶 if(fileName == null){ out = resp.getOutputStream(); out.write("please input fileName".getBytes()); out.close(); } //獲取文件流 in = getServletContext().getResourceAsStream(filePath+ File.separator+fileName); System.out.println(in==null?true:false); int length = in.available(); //設置返回消息頭部信息 resp.setContentType("application/force-download"); resp.setHeader("Content-Length",String.valueOf(length)); resp.setHeader("content-disposition","attachment;filename=\""+fileName+"\""); //輸出文件到客戶端 out = resp.getOutputStream(); int bytesend = 0 ; byte[] buff = new byte[512]; while ((bytesend = in.read(buff))!= -1){ out.write(buff,0,bytesend); } in.close(); out.close(); }} |
web.xml配置
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<servlet> <servlet-name>download</servlet-name> <servlet-class>com.learn.DownLoadServlet</servlet-class> <init-param> <param-name>filePath</param-name> <param-value>file</param-value> </init-param></servlet><servlet-mapping> <servlet-name>download</servlet-name> <url-pattern>/download</url-pattern></servlet-mapping> |
原文鏈接：http://www.cnblogs.com/wwyx-xi/p/7588503.html
