还是用上次文件上传的数据库测试
文件上传：
pom依赖
<dependencies>
<!--springboot整合web项目-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--mysql驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!--mybatis plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.3</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.3.2</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<!--thymeleaf-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--swagger-->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.9.2</version>
</dependency>
<!--fastjson-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.73</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
</dependency>
</dependencies>配置文件（application.yml）
mybatis-plus:
mapper-locations: classpath:mybatis/mapper/*Mapper.xml
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
password: root
url: jdbc:mysql://localhost:3306/fileupload?useSSL=false&useUnicode=true&characterEncoding=UTF8&serverTimezone=Asia/Shanghai
username: root刚才引入了Mybatis-plus和其代码生成器的依赖，现在要来生成代码
Mybatis-plus 代码生成器使用：
Mybatis Plus 代码生成器_HackAzrael的专栏-CSDN博客
https://blog.csdn.net/HackAzrael/article/details/120984912
Controller
注意：这里是根据数据库中的文件id去下载文件
package com.filedownload.controller;
import com.filedownload.entity.File;
import com.filedownload.service.FileService;
import com.filedownload.util.FileDownloadUtils;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiResponse;
import io.swagger.annotations.ApiResponses;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;
/**
* 文件下载控制层
*
* @author az
* @since 2021-10-30
*/
@Controller
@RequestMapping("/file")
public class FileController {
@Resource
private FileService fileService;
@ApiOperation("文件下载")
@ApiResponses({
@ApiResponse(code = 200,message = "下载成功"),
@ApiResponse(code = 510,message = "下载失败"),
})
@ApiImplicitParam(name = "id",value = "文件主键id",dataType = "int",
example = "902727344566087680",required = true)
@GetMapping("/fileDownload")
public @ResponseBody
Map<String, Object> fileDownload(final HttpServletResponse response, long id)throws Exception{
Map<String,Object> map = new HashMap<>();
//通过Mybatis-plus自带的方法根据id查询文件详情
File file = fileService.getById(id);
//获取文件路径
String filePath = file.getFilepath();
//获取文件名
String fileName = file.getFilename();
FileDownloadUtils downloadUtils = new FileDownloadUtils();
boolean res = downloadUtils.download(response, filePath, fileName);
if (res) {
map.put("code",200);
map.put("success",true);
map.put("message","下载成功！");
}else {
map.put("code",510);
map.put("success",false);
map.put("message","下载失败！");
}
return map;
}
}
因为只使用了Mybatis-plus自带的方法查询，这里的业务层、业务层实现类和数据层就不做展示了
FileDownloadUtils
注意：这里的fileName是从数据库中查到的fileName，也就是带前后缀名的文件名
/**
* @author Az
* @Description TODO 文件下载工具类
* @date 2021-10-30
*/
public class FileDownloadUtils {
public boolean download(final HttpServletResponse response,
String filePath,
String fileName) throws Exception{
//获得文件
File file = new File(filePath);
//清空缓冲区，状态码和响应头（header）
response.reset();
//设置ContentType，响应内容为二进制数据流，文件内容编码为UTF-8
response.setContentType("application/octet-stream;charset=utf8");
//设置默认的文件名并设置文件名的编码
response.setHeader("Content-Disposition","attachment;fileName="+ fileName +";filename*=utf-8''"+ URLEncoder.encode(fileName,"utf-8"));
//文件下载
byte[] buffer = new byte[10240];
FileInputStream fileInputStream = null;
BufferedInputStream bufferedInputStream = null;
try {
fileInputStream = new FileInputStream(file);
bufferedInputStream = new BufferedInputStream(fileInputStream);
//获取字节流
OutputStream outputStream = response.getOutputStream();
int i = bufferedInputStream.read(buffer);
while (i != -1){
outputStream.write(buffer, 0, i);
i = bufferedInputStream.read(buffer);
}
return true;
}catch (Exception e){
return false;
}finally {
if (bufferedInputStream != null){
try {
bufferedInputStream.close();
}catch (IOException e){
e.printStackTrace();
}
}
if (fileInputStream != null){
try {
fileInputStream.close();
}catch (IOException e){
e.printStackTrace();
}
}
}
}
}
然后我们用Postman去测试接口是否可以正常使用
这里其实是可以正常显示的，我们点击右边的Save Response->Save to a file保存为文件就可以了
这里的文件名是我们在工具类中设置过的默认文件名
测试可用，结束！
