380 lines
11 KiB
Markdown
380 lines
11 KiB
Markdown
## 任务名称: 文件上传
|
||
### 目标:
|
||
- 掌握框架中文件上传的实现
|
||
- 了解MapStruct的自定义映射
|
||
-
|
||
### 预备知识:
|
||
- [multipart/form-data](../guides/form-data.md)
|
||
|
||
|
||
### 操作步骤
|
||
|
||
对于文件上传，服务器端需要做：
|
||
- **文件上传的接收**
|
||
- **文件存储**
|
||
|
||
存储方案有： 文件系统、云存储（如Amazon S3、阿里云OSS）、数据库（对于小文件）等。
|
||
|
||
本实现使用文件系统存储。
|
||
|
||
#### 1. 撰写附件上传接口的API文档
|
||
|
||
|
||
#### 2. 上传相关的自定义配置
|
||
|
||
在`application.yml`中添加以下配置：
|
||
|
||
```yaml
|
||
app:
|
||
upload:
|
||
path: /home/whz/tmp/upload # 文件上传的存储路径
|
||
sub-path-name-length: 2 # 子路径名称的长度
|
||
base-url: http://localhost:8080/upload # 文件访问的URL
|
||
```
|
||
|
||
实现一个对应的配置类,目的是为了后续的AttachmentMapper中获取配置：
|
||
```java
|
||
package com.lk.paopao.conf;
|
||
|
||
import lombok.Getter;
|
||
import lombok.Setter;
|
||
import org.springframework.boot.context.properties.ConfigurationProperties;
|
||
import org.springframework.stereotype.Component;
|
||
|
||
@Getter
|
||
@Setter
|
||
@Component
|
||
@ConfigurationProperties(prefix = "app.upload")
|
||
public class AppUploadProperties {
|
||
String baseUrl;
|
||
}
|
||
```
|
||
|
||
#### 3. 数据结构
|
||
|
||
**实现附件上传的实体类Attachment**
|
||
|
||
```java
|
||
package com.lk.paopao.entity;
|
||
|
||
import jakarta.persistence.*;
|
||
import lombok.Getter;
|
||
import lombok.Setter;
|
||
import org.hibernate.annotations.ColumnDefault;
|
||
import org.hibernate.annotations.Comment;
|
||
import org.springframework.data.annotation.CreatedDate;
|
||
import org.springframework.data.annotation.LastModifiedDate;
|
||
import org.springframework.data.jpa.domain.support.AuditingEntityListener;
|
||
|
||
@Getter
|
||
@Setter
|
||
@Comment("附件")
|
||
@Entity
|
||
@Table(name = "p_attachment", indexes = {
|
||
@Index(name = "idx_attachment_user", columnList = "user_id")
|
||
})
|
||
@EntityListeners(AuditingEntityListener.class)
|
||
public class Attachment {
|
||
@Id
|
||
@GeneratedValue(strategy = GenerationType.IDENTITY)
|
||
private Long id;
|
||
|
||
@Column(name = "file_size", nullable = false)
|
||
private Long fileSize = 0L;
|
||
|
||
@ColumnDefault("0")
|
||
@Column(name = "img_width", nullable = false)
|
||
private Integer imgWidth = 0;
|
||
|
||
@ColumnDefault("0")
|
||
@Column(name = "img_height", nullable = false)
|
||
private Integer imgHeight = 0;
|
||
|
||
@Comment("1图片，2视频，3其他附件")
|
||
@Column(name = "type", nullable = false)
|
||
private Byte type = 1;
|
||
|
||
@Column(name = "content", nullable = false)
|
||
private String content;
|
||
|
||
@Comment("创建时间")
|
||
@CreatedDate
|
||
@Column(name = "created_on", nullable = false)
|
||
private Long createdOn;
|
||
|
||
@Comment("修改时间")
|
||
@LastModifiedDate
|
||
@Column(name = "modified_on", nullable = false)
|
||
private Long modifiedOn;
|
||
|
||
@Comment("删除时间")
|
||
@Column()
|
||
private Long deletedOn = 0L;
|
||
|
||
@Comment("是否删除 0 为未删除、1 为已删除")
|
||
@Column(name = "is_del", nullable = false)
|
||
private byte isDel = 0;
|
||
|
||
@ManyToOne(fetch = FetchType.LAZY)
|
||
@JoinColumn(name = "user_id")
|
||
private User user;
|
||
|
||
}
|
||
```
|
||
**实现对应的DTO类AttachmentDo**
|
||
```java
|
||
package com.lk.paopao.dto;
|
||
|
||
import lombok.Value;
|
||
|
||
import java.io.Serializable;
|
||
|
||
@Value
|
||
public class AttachmentDto implements Serializable {
|
||
Long id;
|
||
Long fileSize;
|
||
Integer imgWidth;
|
||
Integer imgHeight;
|
||
Byte type;
|
||
String content;
|
||
Long createdOn;
|
||
Long userId;
|
||
}
|
||
```
|
||
**实现对应的MapStruct映射**
|
||
|
||
```java
|
||
package com.lk.paopao.mapper;
|
||
|
||
import com.lk.paopao.conf.AppUploadProperties;
|
||
import com.lk.paopao.dto.AttachmentDto;
|
||
import com.lk.paopao.entity.Attachment;
|
||
import org.mapstruct.*;
|
||
import org.springframework.beans.factory.annotation.Autowired;
|
||
|
||
@Mapper(unmappedTargetPolicy = ReportingPolicy.IGNORE, componentModel = MappingConstants.ComponentModel.SPRING)
|
||
public abstract class AttachmentMapper {
|
||
|
||
@Autowired
|
||
AppUploadProperties appUploadProperties ;
|
||
|
||
@Mapping(source = "user.id", target = "userId")
|
||
@Mapping(target = "content", expression = "java(addHttpPrefix(attachment.getContent()))")
|
||
public abstract AttachmentDto toDto(Attachment attachment);
|
||
|
||
@BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
|
||
public abstract Attachment partialUpdate(AttachmentDto attachmentDto, @MappingTarget Attachment attachment);
|
||
|
||
String addHttpPrefix(String content) {
|
||
if (content != null && !content.startsWith("http://") && !content.startsWith("https://")) {
|
||
// 添加HTTP前缀并去掉"//"
|
||
return appUploadProperties.getBaseUrl() + content;
|
||
}
|
||
return content;
|
||
}
|
||
}
|
||
```
|
||
**注意**：
|
||
- `addHttpPrefix` 方法用于将上传的文件路径转换为完整的URL。
|
||
- 使用了抽象类`AttachmentMapper`，目的是能够使用`@Autowired`注解注入`AppUploadProperties`对象。
|
||
- @Mapping 注解用于指定映射规则。
|
||
- `@BeanMapping` 注解用于指定部分属性的更新策略。
|
||
|
||
#### 4. 创建JPA接口 AttachmentRepository
|
||
```java
|
||
package com.lk.paopao.repository;
|
||
|
||
import com.lk.paopao.entity.Attachment;
|
||
import org.springframework.data.jpa.repository.JpaRepository;
|
||
|
||
public interface AttachmentRepository extends JpaRepository<Attachment, Long> {
|
||
}
|
||
```
|
||
#### 5. 创建对应的Service类AttachService
|
||
|
||
AttachService完成附件上传的业务逻辑。
|
||
|
||
```java
|
||
package com.lk.paopao.service;
|
||
|
||
import com.lk.paopao.dto.AttachmentDto;
|
||
import com.lk.paopao.entity.Attachment;
|
||
import com.lk.paopao.entity.User;
|
||
import com.lk.paopao.mapper.AttachmentMapper;
|
||
import com.lk.paopao.repository.AttachmentRepository;
|
||
import org.springframework.beans.factory.annotation.Autowired;
|
||
import org.springframework.beans.factory.annotation.Value;
|
||
import org.springframework.stereotype.Service;
|
||
import org.springframework.web.multipart.MultipartFile;
|
||
|
||
import java.io.IOException;
|
||
import java.io.InputStream;
|
||
import java.nio.file.Files;
|
||
import java.nio.file.Path;
|
||
import java.nio.file.Paths;
|
||
import java.util.HashMap;
|
||
import java.util.Map;
|
||
import java.util.UUID;
|
||
|
||
@Service
|
||
public class AttachService {
|
||
|
||
// 从配置中获取上传路径
|
||
@Value("${app.upload.path}")
|
||
String UPLOAD_DIR;
|
||
|
||
// 从配置中获取子路径名长度，用于文件分目录存储
|
||
@Value("${app.upload.sub-path-name-length}")
|
||
int SUB_PATH_LENGTH = 1;
|
||
|
||
@Autowired
|
||
AuthService authService;
|
||
@Autowired
|
||
AttachmentRepository attachmentRepository;
|
||
@Autowired
|
||
AttachmentMapper attachmentMapper;
|
||
|
||
|
||
/**
|
||
* 上传附件
|
||
* @param file 文件
|
||
* @return AttachmentDto
|
||
* @throws IOException 输入输出异常
|
||
*/
|
||
public AttachmentDto upload(MultipartFile file) throws IOException {
|
||
// 获取原始文件名
|
||
String originFileName = file.getOriginalFilename();
|
||
if(originFileName == null){
|
||
throw new IllegalArgumentException("没有原始文件名");
|
||
}
|
||
|
||
InputStream inputStream = file.getInputStream();
|
||
// 获取当前用户
|
||
User currentUser = authService.getCurrentUser();
|
||
// 上传文件并获取相对URL
|
||
String relativeUrl = save(originFileName,inputStream);
|
||
Attachment attachment = new Attachment();
|
||
// 设置附件类型
|
||
attachment.setType(getType(file.getContentType()));
|
||
// 设置附件内容（即存储的URL）
|
||
attachment.setContent(relativeUrl);
|
||
// 关联用户
|
||
attachment.setUser(currentUser);
|
||
// 设置文件大小
|
||
attachment.setFileSize(file.getSize());
|
||
// 保存附件
|
||
Attachment savedAttachment = attachmentRepository.save(attachment);
|
||
// 转换并返回附件DTO
|
||
return attachmentMapper.toDto(savedAttachment);
|
||
}
|
||
|
||
/**
|
||
* 保存文件到上传目录中
|
||
* @param fileName 原文件名
|
||
* @param fileStream 文件流
|
||
* @return 保存后的文件访问路径
|
||
* @throws IOException 文件操作异常
|
||
*/
|
||
public String save(String fileName, InputStream fileStream) throws IOException {
|
||
// 生成新的文件名以避免重复
|
||
String rename = UUID.randomUUID().toString();
|
||
int dotIndex = fileName.lastIndexOf('.');
|
||
// 新文件名，包含扩展名
|
||
String newFile = rename+((dotIndex > 0) ? "."+fileName.substring(dotIndex + 1) : "");
|
||
|
||
// 根据子路径长度计算文件保存的子目录
|
||
String subPath = rename.substring(0,SUB_PATH_LENGTH);
|
||
// 完整的保存路径
|
||
String uploadPath = UPLOAD_DIR+"/"+subPath;
|
||
|
||
// 确保目录存在，不存在则创建
|
||
Path directory = Paths.get(uploadPath);
|
||
if (!Files.exists(directory)) {
|
||
Files.createDirectories(directory);
|
||
}
|
||
// 文件的最终保存位置
|
||
Path targetLocation = Paths.get(uploadPath, newFile);
|
||
// 复制文件流到目标位置
|
||
Files.copy(fileStream, targetLocation);
|
||
// 返回文件的访问路径
|
||
return "/"+subPath+"/"+newFile;
|
||
}
|
||
|
||
/**
|
||
* 根据文件的MIME类型返回文件类型标识
|
||
* @param contentType 文件的MIME类型
|
||
* @return 文件类型的标识字节，0表示未知类型
|
||
*/
|
||
public static byte getType(String contentType) {
|
||
|
||
if(contentType == null){
|
||
return 0;
|
||
}
|
||
if(contentType.startsWith("image/")){
|
||
return 1;
|
||
}
|
||
if(contentType.startsWith("video/")){
|
||
return 2;
|
||
}
|
||
if(contentType.startsWith("application/")){
|
||
return 3;
|
||
}
|
||
if(contentType.startsWith("text/")){
|
||
return 4;
|
||
}
|
||
return 0;
|
||
}
|
||
}
|
||
```
|
||
#### 6. 创建控制器AttachmentController
|
||
|
||
```java
|
||
package com.lk.paopao.controller;
|
||
|
||
|
||
import com.lk.paopao.dto.AttachmentDto;
|
||
import com.lk.paopao.dto.rest.response.DataResult;
|
||
import com.lk.paopao.dto.rest.response.ResultUtil;
|
||
import com.lk.paopao.service.AttachService;
|
||
import org.springframework.beans.factory.annotation.Autowired;
|
||
import org.springframework.http.MediaType;
|
||
import org.springframework.web.bind.annotation.PostMapping;
|
||
import org.springframework.web.bind.annotation.RequestMapping;
|
||
import org.springframework.web.bind.annotation.RequestParam;
|
||
import org.springframework.web.bind.annotation.RestController;
|
||
import org.springframework.web.multipart.MultipartFile;
|
||
|
||
import java.io.IOException;
|
||
|
||
@RestController
|
||
@RequestMapping("${app.version}/attachment")
|
||
public class AttachmentController {
|
||
@Autowired
|
||
AttachService attachService;
|
||
|
||
@PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
|
||
public DataResult<AttachmentDto> upload(@RequestParam("file") MultipartFile file) throws IOException {
|
||
|
||
AttachmentDto dto = attachService.upload(file);
|
||
return ResultUtil.ok(dto);
|
||
}
|
||
}
|
||
|
||
```
|
||
说明：
|
||
- @RequestParam("file"): 表示请求参数中的文件
|
||
|
||
### 技术/工具需求:
|
||
- [列出完成任务所需的技术栈、工具、软件版本等。]
|
||
|
||
### 成功标准:
|
||
- [明确完成任务的评判标准，如代码功能实现、性能指标、测试通过条件等。]
|
||
|
||
### 扩展学习(可选):
|
||
- [提供一些额外学习资源或挑战性任务，鼓励学有余力的学生进一步探索。]
|
||
|
||
### 评估与反馈:
|
||
- [说明如何提交作业、代码审查的标准、或任何反馈收集机制。]
|
||
|
||
### 时间估算:
|
||
- [给出预计完成该任务所需的时间，帮助学生合理安排学习计划。] |