使用Springboot+Vue实现文件上传和下载功能

CREATE TABLE `book` (
    `id` int(10) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
`name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '图书名称',
`price` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '图书价格',
`author` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '图书作者',
`press` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '图书出版社',
`img` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '图书封面',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

@Table(name = "book")
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    @Column(name = "name")
    private String name;
    @Column(name = "price")
    private String price;
    @Column(name = "author")
    private String author;
    @Column(name = "press")
    private String press;
    @Column(name = "img")
    private String img;
}

import com.example.entity.Book;
import com.example.entity.Params;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
import tk.mybatis.mapper.common.Mapper;
import java.util.List;
@Repository
public interface BookDao extends Mapper<Book> {
    List<Book> findBySearch(@Param("params") Params params);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.dao.BookDao">
<select id="findBySearch" resultType="com.example.entity.Book">
select * from book
<where>
<if test="params != null and params.name != null and params.name != ''">
and name like concat('%', #{ params.name }, '%')
</if>
<if test="params != null and params.author != null and params.author != ''">
and author like concat('%', #{ params.author }, '%')
</if>
</where>
</select>
</mapper>

import com.example.dao.BookDao;
import com.example.entity.Book;
import com.example.entity.Params;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class BookService {
    @Resource
    private BookDao bookDao;
    public PageInfo<Book> findBySearch(Params params) {
        // 开启分页查询
        PageHelper.startPage(params.getPageNum(), params.getPageSize());
        // 接下来的查询会自动按照当前开启的分页设置来查询
        List<Book> list = bookDao.findBySearch(params);
        return PageInfo.of(list);
    }
    public void add(Book book) {
        bookDao.insertSelective(book);
    }
    public void update(Book book) {
        bookDao.updateByPrimaryKeySelective(book);
    }
    public void delete(Integer id) {
        bookDao.deleteByPrimaryKey(id);
    }
}

import com.example.common.Result;
import com.example.entity.Book;
import com.example.entity.Params;
import com.example.service.BookService;
import com.github.pagehelper.PageInfo;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
@CrossOrigin
@RestController
@RequestMapping("/book")
public class BookController {
    @Resource
    private BookService bookService;
    @GetMapping("/search")
    public Result findBySearch(Params params) {
        PageInfo<Book> info = bookService.findBySearch(params);
        return Result.success(info);
    }
    @PostMapping
    public Result save(@RequestBody Book book) {
        if (book.getId() == null) {
            bookService.add(book);
        } else {
            bookService.update(book);
        }
        return Result.success();
    }
    @DeleteMapping("/{id}")
    public Result delete(@PathVariable Integer id) {
        bookService.delete(id);
        return Result.success();
    }
}

package com.example.controller;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.StrUtil;
import com.example.common.Result;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
/**
 *  文件上传接口
 */
@RestController
@RequestMapping("/files")
public class FileController {
    // 文件上传存储路径
    private static final String filePath = System.getProperty("user.dir") + "/file/";
    /**
     * 文件上传
     */
    @PostMapping("/upload")
    public Result upload(MultipartFile file) {
        synchronized (FileController.class) {
            String flag = System.currentTimeMillis() + "";
            String fileName = file.getOriginalFilename();
            try {
                if (!FileUtil.isDirectory(filePath)) {
                    FileUtil.mkdir(filePath);
                }
                // 文件存储形式：时间戳-文件名
                FileUtil.writeBytes(file.getBytes(), filePath + flag + "-" + fileName);
                System.out.println(fileName + "--上传成功");
                Thread.sleep(1L);
            } catch (Exception e) {
                System.err.println(fileName + "--文件上传失败");
            }
            return Result.success(flag);
        }
    }
    /**
     * 获取文件
     */
    @GetMapping("/{flag}")
    public void avatarPath(@PathVariable String flag, HttpServletResponse response) {
        if (!FileUtil.isDirectory(filePath)) {
            FileUtil.mkdir(filePath);
        }
        OutputStream os;
        List<String> fileNames = FileUtil.listFileNames(filePath);
        String avatar = fileNames.stream().filter(name -> name.contains(flag)).findAny().orElse("");
        try {
            if (StrUtil.isNotEmpty(avatar)) {
                response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(avatar, "UTF-8"));
                response.setContentType("application/octet-stream");
                byte[] bytes = FileUtil.readBytes(filePath + avatar);
                os = response.getOutputStream();
                os.write(bytes);
                os.flush();
                os.close();
            }
        } catch (Exception e) {
            System.out.println("文件下载失败");
        }
    }
}

// 加自定义拦截器JwtInterceptor，设置拦截规则
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(jwtInterceptor).addPathPatterns("/api/**")
.excludePathPatterns("/api/files/**")
.excludePathPatterns("/api/admin/login")
.excludePathPatterns("/api/admin/register");
}

<el-form-item label="图书封面" label-width="20%">
<el-upload action="http://localhost:8080/api/files/upload" :on-success="successUpload">
<el-button size="small" type="primary">点击上传</el-button>
</el-upload>
</el-form-item>

successUpload(res) {
    this.form.img = res.data;
},

<el-table-column label="图书封面">
<template v-slot="scope">
<el-image
style="width: 70px; height: 70px; border-radius: 50%"
:src="'http://localhost:8080/api/files/' + scope.row.img"
:preview-src-list="['http://localhost:8080/api/files/' + scope.row.img]">
</el-image>
</template>
</el-table-column>
<el-button type="primary" @click="down(scope.row.img)">下载</el-button>

down(flag) {
    location.href = 'http://localhost:8080/api/files/' + flag
}