SpringMVC 使用RestFul风格实现简单的文件下载

╰+哭是因爲堅強的太久メ 2021-09-21 16:02 378阅读 0赞

# 配置文件 #

SpringMVC 配置和依赖：[https://blog.csdn.net/weixin\_44953227/article/details/113319129][https_blog.csdn.net_weixin_44953227_article_details_113319129]

# 文件下载的 Controller #

注意：restFul 风格一般会把文件后缀名截取掉, 加上 `:.+` 来保留文件后缀名

package com.pro.controller;
    
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.URLEncoder;
    
    @RestController
    public class FileController { 
    
    	// 使用restFul风格一般会把文件后缀名截取掉, 加上:.+ 来保留文件后缀名
        @RequestMapping(value = "/download/{fileName:.+}")
        public String download(@PathVariable String fileName, HttpServletResponse response, HttpServletRequest request) throws Exception { 
            System.out.println("download --> " + fileName);
            //要下载的图片地址
            String path = request.getServletContext().getRealPath("/upload");
    
            //1、设置response 响应头
            response.reset(); //设置页面不缓存,清空buffer
            response.setCharacterEncoding("UTF-8"); //字符编码
            response.setContentType("multipart/form-data"); //二进制传输数据
            //设置响应头
            response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode(fileName, "UTF-8"));
    
            File file = new File(path, fileName);
            //2、 读取文件--输入流
            InputStream input = new FileInputStream(file);
            //3、 写出文件--输出流
            OutputStream out = response.getOutputStream();
    
            //4、执行 写出操作
            byte[] buff = new byte[1024];
            int index = 0;
            while ((index = input.read(buff)) != -1) { 
                out.write(buff, 0, index);
                out.flush();
            }
    
            // 关闭流
            out.close();
            input.close();
            return null;
        }
    }

# 测试 #

启动项目访问：http://localhost:8080/download/xxx.xx

我的项目中有一个 aa.pdf 的文件， 就直接访问

http://localhost:8080/download/aa.pdf

[https_blog.csdn.net_weixin_44953227_article_details_113319129]: https://blog.csdn.net/weixin_44953227/article/details/113319129