这是我的用户类。
@Entity
@Table(name = "user_table")
@Data
public class User {
@Id
private Long id;
private String userName;
private String password;
}
这是我的 UserDto,我知道字段名称是相同的。但我正在尝试理解这个概念。
@Data
public class UserDto {
private Long id;
private String userName;
private String password;
}
我想使用 MapStruct 进行 Entity-Dto 和 Dto-Entity 转换。所以我写了一个像 EntityMapper 这样的基本接口。
public interface EntityMapper<D, E> {
E toEntity(D dto);
D toDto(E entity);
List<E> toEntity(List<D> dtoList);
List<D> toDto(List<E> entityList);
}
然后我创建了一个新的接口,它扩展了 EntityMapper .
@Mapper(componentModel = "spring", uses = UserService.class)
public interface UserMapper extends EntityMapper<UserDto , User> {
@Mapping(source = "id", target = "id")
@Mapping(source = "userName", target = "userName")
@Mapping(source = "password", target = "password")
@Override
User toEntity(UserDto dto);
@Override
UserDto toDto(User entity);
@Override
List<User> toEntity(List<UserDto> dtoList);
@Override
List<UserDto> toDto(List<User> entityList);
这是我的控制器
@RestController
@RequestMapping("/v1/api/users")
public class UserController {
private final UserService userService;
public UserController(UserService userService) {
this.userService = userService;
}
@PostMapping("/save")
public ResponseEntity<UserDto> saveUser(@RequestBody UserDto userDto){
UserDto res = userService.saveUser(userDto);
return ResponseEntity.ok(res);
}
}
最后,当我尝试创建一个新的服务类并使用 UserMapper 接口的引用时。春天告诉我
无法自动装配。未找到“UserMapper”类型的 bean。
对于这条线
private final UserMapper userMapper;
这就是我的整个服务级别。当我删除 @Service 注释时,错误已修复。但这是一个服务类,所以我认为我必须添加 @Service 注释。
我尝试向 UserMapper 添加 @Component 注释。但应用程序无法启动。
@Service
public class UserService {
private final UserRepository userRepository;
private final UserMapper userMapper;
public UserService(UserRepository userRepository, UserMapper userMapper) {
this.userRepository = userRepository;
this.userMapper = userMapper;
}
public UserDto saveUser(UserDto userDto){
User user = userMapper.toEntity(userDto);
user = userRepository.save(user);
UserDto res = userMapper.toDto(user);
return res;
}
}
这是 pom.xml。
<?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>2.6.6</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>AprilSevenApp</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>AprilSevenApp</name>
<description>AprilSevenApp</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct -->
<dependency>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct</artifactId>
<version>1.4.2.Final</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.dot</groupId>
<artifactId>util</artifactId>
<version>0.2.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
我刚刚添加了映射结构的依赖关系。如果我必须添加不同的依赖项,我不知道。
<!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct --
>
<dependency>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct</artifactId>
<version>1.4.2.Final</version>
</dependency>
必须将注释处理器添加到编译器插件中才能生成
UserMapper
接口的实现。
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<annotationProcessorPaths>
<path>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct-processor</artifactId>
<version>1.4.2.Final</version>
</path>
</annotationProcessorPaths>
</configuration>
</plugin>
此外,考虑到
uses = UserService.class
不是映射器,我认为不能删除 UserService
。这是uses
注解参数的官方文档:
此映射器使用的其他映射器类型。可能是手写的类或由 MapStruct 生成的其他映射器。生成的映射器类之间不必创建循环。
添加到Mapper注释中的一段代码帮助我解决了这个问题
@Mapper(componentModel = "spring")