Java HttpServletResponse（实现重定向和下载文件）

1、下载示例

package com.cc.hello;
 
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;
 
public class realDownLoad extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String realPath="E:\\IdeaProjects\\javaweb-01\\Servlet\\src\\main\\resources\\db.properties";
        System.out.println("下载文件的路径："+realPath);
        String name = realPath.substring(realPath.lastIndexOf("\\") + 1);
        resp.setHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(name,"UTF-8"));
        FileInputStream stream = new FileInputStream(realPath);
        int len=0;
        byte[]by=new byte[1024];
        ServletOutputStream outputStream = resp.getOutputStream();
        while ((len=stream.read(by))>0){
            outputStream.write(by,0,len);
        }
        stream.close();
        outputStream.close();
 
    }
 
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

2、也可直接在GET接口返回

@RequestMapping(value="download", methon=RequestMothod.GET)
public void download(HeepServletResponse resp) throws ServletException,IOException {

　　　　String realPath="E:\\IdeaProjects\\javaweb-01\\Servlet\\src\\main\\resources\\db.properties";
        System.out.println("下载文件的路径："+realPath);
        String name = realPath.substring(realPath.lastIndexOf("\\") + 1);
        resp.setHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(name,"UTF-8"));
        FileInputStream stream = new FileInputStream(realPath);
        int len=0;
        byte[]by=new byte[1024];
        ServletOutputStream outputStream = resp.getOutputStream();
        while ((len=stream.read(by))>0){
            outputStream.write(by,0,len);
        }
        stream.close();
        outputStream.close();

}