springboot成神之——spring文件下载功能

• 本文介绍spring文件下载功能
  • 目录结构
  • DemoApplication
  • WebConfig
  • TestController
  • MediaTypeUtils
  • 前端测试

本文介绍spring文件下载功能

目录结构

DemoApplication

package com.springlearn.learn;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}
}

WebConfig

package com.springlearn.learn.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**").allowedOrigins("*").allowedMethods("GET", "POST", "PUT", "DELETE").allowedOrigins("*")
        .allowedHeaders("*");
    }
}

TestController

package com.springlearn.learn.controller;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletResponse;

import com.springlearn.learn.utils.MediaTypeUtils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class TestController {

    @Autowired
    private ServletContext servletContext;

    @ResponseBody
    @RequestMapping(value = "/DownLoadTest", method = RequestMethod.GET)
    public void Test(@RequestParam(defaultValue = "spring-boot-reference.pdf") String fileName, HttpServletResponse response) throws IOException {
        MediaType mediaType = MediaTypeUtils.getMediaTypeForFileName(this.servletContext, fileName);

        System.out.println("fileName: " + fileName);
        System.out.println("mediaType: " + mediaType);

        String filepath = "C:\Users\26401\Desktop\learn";
        File file = new File(filepath + File.separator + fileName);

        response.setContentType(mediaType.getType());
        response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + file.getName());
        response.setContentLength((int) file.length());

        BufferedInputStream inStream = new BufferedInputStream(new FileInputStream(file));
        BufferedOutputStream outStream = new BufferedOutputStream(response.getOutputStream());

        byte[] buffer = new byte[1024];
        int bytesRead = 0;
        while ((bytesRead = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, bytesRead);
        }
        outStream.flush();
        inStream.close();
    }
}

MediaTypeUtils

package com.springlearn.learn.utils;

import javax.servlet.ServletContext;

import org.springframework.http.MediaType;

public class MediaTypeUtils {
    public static MediaType getMediaTypeForFileName(ServletContext servletContext, String fileName) {
        String mineType = servletContext.getMimeType(fileName);
        try {
            MediaType mediaType = MediaType.parseMediaType(mineType);
            return mediaType;
        } catch (Exception e) {
            return MediaType.APPLICATION_OCTET_STREAM;
        }
    }
     
}

前端测试

直接访问 http://localhost:9001/DownLoadTest 即可