Servlet读取资源文件（文件的下载）

1. 文件名非中文：

 package ztq.servlet.study;

 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;

 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 public class ServletDemo1 extends HttpServlet {
     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         //获取要下载的文件
         ServletContext sc = getServletContext();
         String path = sc.getRealPath("/pic.jpg");

         //通知客户端以下载的方式打开
         response.setHeader("Content-Disposition", "attachment;filename = pic.jpg" );
         response.setHeader("Content-type", "application/octet-stream");

         //构建输入输出流
         InputStream in = new FileInputStream(path);
         OutputStream out = response.getOutputStream();
         byte[] buf = new byte[1024];
         int len = 0;
         while((len = in.read(buf)) != -1){
             out.write(buf, 0, len);
         }
         in.close();
         out.close();
     }
     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         doGet(request, response);
     }
 }

2. 文件名含中文：

 package ztq.servlet.study;

 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URLEncoder;

 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 public class ServletDemo1 extends HttpServlet {
     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         //获取要下载的文件
         ServletContext sc = getServletContext();
         String path = sc.getRealPath("/人物.jpg");

         //截取文件名
         String filename = path.substring(path.lastIndexOf("\\") + 1);

         //通知客户端以下载的方式打开
         response.setHeader("Content-Disposition", "attachment;filename = " + URLEncoder.encode(filename, "UTF-8"));
         response.setHeader("Content-type", "application/octet-stream");

         //构建输入输出流
         InputStream in = new FileInputStream(path);
         OutputStream out = response.getOutputStream();
         byte[] buf = new byte[1024];
         int len = 0;
         while((len = in.read(buf)) != -1){
             out.write(buf, 0, len);
         }
         in.close();
         out.close();
     }
     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         doGet(request, response);
     }
 }