27.文件上传下载

一、快速入门

-application.yml配置上传的路径

reggie:
  path: C:\Users\Pipiktd\Pictures\

• controller

package com.ylf.controller;

import com.ylf.common.CustomException;
import com.ylf.common.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * @author ylf
 * @version 1.0
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
  @Value("${reggie.path}")
  private String path;

  @PostMapping("/upload")
  /** MultipartFile是spring提供的类，file必须和前端input的name值对应 */
  public Result<String> upload(MultipartFile file) {
    log.info(file.toString());
    // 获取原始文件名
    final String originalFilename = file.getOriginalFilename();
    final String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
    // 使用uuid拼接组成文件名
    String fileName = UUID.randomUUID().toString() + suffix;
    try {
      file.transferTo(new File(path + fileName));
    } catch (IOException e) {
      e.printStackTrace();
    }
    return Result.success(fileName);
  }

  @GetMapping("/download")
  public void download(String name, HttpServletResponse response) {
    try {
      final FileInputStream fileInputStream = new FileInputStream(new File(path + name));
      final ServletOutputStream outputStream = response.getOutputStream();
      response.setContentType("image/jpeg");
      int len = 0;
      final byte[] bytes = new byte[1024];
      while ((len = fileInputStream.read(bytes)) != -1) {
        outputStream.write(bytes, 0, len);
        outputStream.flush();
      }
      outputStream.close();
      fileInputStream.close();
    } catch (Exception e) {
      throw new CustomException("文件不存在");
    }
  }
}