SpringBoot上传和下载文件

SpringBoot上传和下载文件

创建表

DROP TABLE IF EXISTS `file`;
CREATE TABLE `file`  (
  `id` int(0) NOT NULL,
  `filename` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '文件名',
  `path` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '文件地址',
  `status` int(0) NULL DEFAULT NULL COMMENT '文件状态 1:删除 0:正常',
  `create_time` datetime(0) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

创建SpringBoot项目然后导入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.1.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>top.gaoqiulin</groupId>
    <artifactId>fileupload</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>fileupload</name>
    <description>fileupload</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>21</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.30</version>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.8.25</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

创建类

创建统一返回类

import lombok.Data;

import java.io.Serializable;

@Data
public class Result implements Serializable {
    private static final long serialVersionUID = 1L;
    
    private Integer code;
    
    private String msg;
    
    private Object data;

    public Result(Integer code, String msg, Object data) {
        this.code = code;
        this.msg = msg;
        this.data = data;
    }
    public Result(Integer code, String msg) {
        this.code = code;
        this.msg = msg;
    }
    public Result(Integer code) {
        this.code = code;
    }
}

创建统异常类

import lombok.Data;

@Data
public class BizException extends RuntimeException{

    private Integer code;

    private String msg;

    public static BizException of(Integer code,String msg){
        BizException bizException = new BizException();
        bizException.setCode(code);
        bizException.setMsg(msg);
        return bizException;
    }

    public static BizException of(String msg){
        BizException bizException = new BizException();
        bizException.setCode(500);
        bizException.setMsg(msg);
        return bizException;
    }
}

创建实体类

import lombok.Data;

import java.io.Serializable;
import java.util.Date;

@Data
public class File implements Serializable {
    private static final long serialVersionUID = 1L;

    private String id;

    private String filename;

    private String path;

    private Integer status;

    private Date createTime;
}

创建Mapper

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import top.gaoqiulin.fileupload.domain.entity.File;
@Mapper
public interface FileUploadMapper extends BaseMapper<File> {
}

创建Service

import com.baomidou.mybatisplus.extension.service.IService;
import org.springframework.web.multipart.MultipartFile;
import top.gaoqiulin.fileupload.domain.entity.File;


public interface FileUploadService extends IService<File> {
  String upload(MultipartFile file);

  void download(String fileId, HttpServletResponse response); 
}

创建ServiceImpl

import cn.hutool.core.io.FileUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import jakarta.annotation.Resource;
import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import top.gaoqiulin.fileupload.domain.entity.File;
import top.gaoqiulin.fileupload.exception.BizException;
import top.gaoqiulin.fileupload.mapper.FileUploadMapper;
import top.gaoqiulin.fileupload.service.FileUploadService;

import java.io.IOException;
import java.util.Date;
import java.util.UUID;

@Service
@Slf4j
public class FileUploadServiceImpl extends ServiceImpl<FileUploadMapper, File> implements FileUploadService {
    @Resource
    private FileUploadMapper fileUploadMapper;

    @Value("${upload}")
    private String upload;
    
    @Override
    public String upload(MultipartFile file) {
        String originalFilename = file.getOriginalFilename();
        String mainName = FileUtil.mainName(originalFilename);
        String extName = FileUtil.extName(originalFilename);
        String fileName = mainName + UUID.randomUUID().toString().replaceAll("-", "") + "." + extName;

        String absolutePath = upload + fileName;

        try {
            FileUtil.writeBytes(file.getBytes(), absolutePath);
        } catch (IOException e) {
            log.error("文件上传失败{}", e.getMessage());
            throw BizException.of("文件上传失败");
        }
        File fileUpload = new File();
        fileUpload.setId(UUID.randomUUID().toString().replaceAll("-", ""));
        fileUpload.setFilename(fileName);
        fileUpload.setPath(absolutePath);
        fileUpload.setStatus(0);
        fileUpload.setCreateTime(new Date());
        save(fileUpload);
        return fileUpload.getId();
    }



    @Override
    public void download(String fileId, HttpServletResponse response) {
        File file = getById(fileId);
        if (file == null) {
            throw BizException.of("文件不存在");
        }
        java.io.File file1 = FileUtil.file(file.getPath());
        //吧文件输出到响应流
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition", "attachment;filename=" + file.getFilename());
        try (
                ServletOutputStream outputStream = response.getOutputStream();
        ) {
            outputStream.write(FileUtil.readBytes(file1));
        } catch (IOException e) {
            throw BizException.of("文件下载失败");
        }


    }
}

创建Controller

import jakarta.annotation.Resource;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import top.gaoqiulin.fileupload.service.FileUploadService;
import top.gaoqiulin.fileupload.utils.Result;

@RequestMapping("/file")
@RestController
public class FileController {

    @Resource
    private FileUploadService fileUploadService;
    
    @PostMapping(value = "/upload",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public Result upload(@RequestPart("file") MultipartFile file) {
       String fileId= fileUploadService.upload(file);
       return new Result(200,"上传成功",fileId);
    }
    
    
    @GetMapping("/download/{fileId}")
    public void download(@PathVariable String fileId, HttpServletResponse response) {
        fileUploadService.download(fileId,response);


    }
}

修改配置文件

spring.application.name=fileupload
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost/fileupload?serverTimeZone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root
upload=D:\\idea\\workspace\\fileupload\\fileupload\\src\\main\\resources\\upload\\

上面步骤操作完就可以进行测试了。