Mapstruct 实现

Question

我正在使用 mapstruct 将我的模型映射到我的 DTO。 我想按全名搜索记录。 我不明白为什么会出现以下错误：

Error creating bean with name 'customerController'
Error creating bean with name 'customerServiceImpl'
Error creating bean with name 'customerRepository'
No property name found for type Customer!

这是我的项目

public interface CustomerMapper {

    CustomerMapper INSTANCE = Mappers.getMapper(CustomerMapper.class);
    @Mapping(source = "lastName", target = "lastName")
    CustomerDTO customerToCustomerDTO(Customer customer);
}

@Data
public class CustomerDTO {
    private String firstName;
    private String lastName;
}

@Data
@Entity
@Getter
@Setter
public class Customer {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String firstName;
    private String name;
}

@Data
@NoArgsConstructor
@AllArgsConstructor
public class CustomerListDTO {
    List<CustomerDTO> categories;
}

@Controller
@RequestMapping("api/v1/customers")

public class CustomerController {
    private final CustomerService customerService;


    public CustomerController(CustomerService customerService) {
        this.customerService = customerService;
    }

    @GetMapping("{name}")
    public ResponseEntity<CustomerDTO> getCustomerByName(@PathVariable String name) {
        return new ResponseEntity<>(
                customerService.getCustomerByName(name), HttpStatus.OK
        );
    }

public interface CustomerRepository extends JpaRepository<Customer, Long> {
    Customer findByName(String x);
}

public interface CustomerService {
    CustomerDTO getCustomerByName(String name);
}

@AllArgsConstructor
@Service
public class CustomerServiceImpl implements CustomerService {

    CustomerMapper customerMapper;
    CustomerRepository customerRepository;

    @Override
    public CustomerDTO getCustomerByName(String lastName) {
        return customerMapper.customerToCustomerDTO(customerRepository.findByName(lastName));
    }
}

这是一个潜在的解决方法：将在 CustomerMapper 中映射以下内容，但对我来说感觉不对。

@Mapping(source = "name", target = "lastName")
@Mapping(source = "firstName", target = "firstName")

在文档中，据说您可以将模型中的任何字段映射到 DTO，我认为我的代码可能有问题。 我尝试在 repo、service、controller 中实现的方式。

编辑：

也许解决方案是在存储库中使用 DTO？

更新：

@Override
    public CustomerDTO getCustomerByName(String lastName) {
        return customerRepository.findByName(lastName).map(customerMapper::customerToCustomerDTO);
    }

.map 无法使用。

要使用 .map 我应该使用这样的代码

    .findAll()
    .stream()
    .map(customerMapper::customerToCustomerDTO)
    .collect(Collectors.toList());

我正在使用 findByName 方法，但它无法访问 .map。

我该如何解决这个问题？

编辑

这就是我认为我的客户应该是什么样子

@Data
@NoArgsConstructor
@AllArgsConstructor
public class CustomerDTO {
    private String id;
    private String firstName;
    private String lastName;
}

Answer 1

“未找到类型 Customer 的属性名称！”

在您的餐桌客户中，您有一个名为“name”的列？

下面我对您的代码进行了一些更改，但是如果您需要按名称查找您的存储库，则需要找到正确的搜索。当您使用 findByName 时，仅返回名称等于传入参数的名称的行。示例：findByName("Scilla") 仅返回列名等于“Scilla”的行，如果列名具有“scilla”（下）或“Scilla abc”等值，则查询未返回此条目。

值为“Scilla”的方法 findByName 生成此查询：

select * from customer where name = 'Scilla';

代码更改

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

public interface CustomerRepository extends JpaRepository<Customer, Long> {
    
    Customer findByLastName(String lastName);
    
    List<Customer> findByLastNameContainingIgnoreCase(String name);

    List<Customer> findByLastNameContaining(String name);

}

import org.mapstruct.Mapper;
import org.mapstruct.factory.Mappers;

@Mapper
public interface CustomerMapper {

    CustomerMapper INSTANCE = Mappers.getMapper(CustomerMapper.class);

    CustomerDTO customerToCustomerDTO(Customer customer);

    Customer toDomain(CustomerDTO customerDTO);
    
}

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@Entity
@NoArgsConstructor
public class Customer {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String firstName;
    
    private String lastName;
    
}

import lombok.Data;

@Data
public class CustomerDTO {

    private String firstName;
    private String lastName;

}

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("api/v1/customers")
public class CustomerController {

    private final CustomerService customerService;


    public CustomerController(CustomerService customerService) {
        this.customerService = customerService;
    }

    @GetMapping("{name}")
    public ResponseEntity<CustomerDTO> getCustomerByName(@PathVariable String name) {
        return new ResponseEntity<>(
                customerService.getCustomerByName(name), HttpStatus.OK
        );
    }
    
    @PostMapping
    public ResponseEntity<CustomerDTO> getCustomerByName(@RequestBody CustomerDTO customerDTO ) {
        return new ResponseEntity<>(
                customerService.save(customerDTO), HttpStatus.OK
        );
    }
    
}

重要

下面放Spring Data查询和翻译查询。

List<Customer> findByLastNameContainingIgnoreCase(String name)

select * from customer where last_name ilike = '%name%';

pom.xml 定义

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>11</java.version>
        
        <org.mapstruct.version>1.4.1.Final</org.mapstruct.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct</artifactId>
            <version>1.4.1.Final</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <forceJavacCompilerUse>true</forceJavacCompilerUse>
                    <release>11</release>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.mapstruct</groupId>
                            <artifactId>mapstruct-processor</artifactId>
                            <version>${org.mapstruct.version}</version>
                        </path>
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                            <version>${lombok.version}</version>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
        </plugins>
    </build>

Answer 2

要将您的客户实体映射到 DTO 并在 Spring 应用程序中使用它，您应该使用以下映射器（带有参数 componentModel = "spring"）：

@Mapper(
    componentModel = "spring",
    nullValueMappingStrategy = NullValueMappingStrategy.RETURN_DEFAULT,
    nullValueCheckStrategy = NullValueCheckStrategy.ALWAYS,
    nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE
)
public interface CustomerMapper {
   @Mapping(target = "lastName", source = "name")
   CustomerDto toDto(Customer customer);
}

MapStruct 不知道如何将实体中的 name 属性映射到 DTO 中的 lastName 属性，因此您必须在 @Mapping 注释中指定。

（我还建议使用“策略”参数的指定值 - 您可以在 javadoc 中查看它们的用途。）

在这种情况下，MapStruct 会生成一个适当的 Spring bean，其中包含映射器的实现，如下所示：

@Component
public class CustomerMapperImpl {

    public CustomerDto toDto(Customer customer) {
        CustomerDto dto = new CustomerDto();
        if (customer != null) {
            if (customer.getFirstName() != null) {
                dto.setFirstName(customer.getFirstName());
            }
            if (customer.getName() != null) {
                dto.setLastName(customer.getName());
            }        
        }
        return dto;
    }
}

因此 Spring 将能够在您的服务中注入该 bean（不要忘记更正您的 repo 的 findByName 方法以返回 Optional）：

@RequiredArgsConstructor
@Service
public class CustomerServiceImpl implement CustomerService {

    private final CustomerRepo repo;
    private final CustomerMapper mapper;

    @Override 
    public Optional<CustomerDto> getByName(@NonNull String name) {
        return repo.findByName(name).map(mapper::toDto)
    }
    
    @Override 
    public List<CustomerDto> getAll() {
        return repo.findAll().stream().map(mapper::toDto).collect(Collectors.toList());
    }
}

然后在您的 REST 控制器中使用此服务：

@RequiredArgsConstructor
@RestController
@RequestMapping("api/v1/customers")
public class CustomerController {

    private final CustomerService service;

    @GetMapping("/{name}")
    public CustomerDto getByName(@PathVariable String name) {
        return service.getByName()
            .orElseThrow(() -> new ResponseStatusException("Customer not found"));
    }

    @GetMapping
    public List<CustomerDto> getAll() {
        return service.getAll();
    }
}

不要忘记将您的项目配置为同时使用 MapStruct 和 Lombok：

      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <annotationProcessorPaths>
            <path>
              <groupId>org.projectlombok</groupId>
              <artifactId>lombok</artifactId>
              <version>${lombok.version}</version>
            </path>
            <path>
              <groupId>org.mapstruct</groupId>
              <artifactId>mapstruct-processor</artifactId>
              <version>${mapstruct.version}</version>
            </path>
          </annotationProcessorPaths>
        </configuration>
      </plugin>