java - MapStruct 无法识别 @Mapping 中的字段 - 简单配置

Question

这个问题在这里已经有了答案:

MapStruct and Lombok not working together (15 个回答)

关闭 1年前。

我有两个类。型号:

@Data
public class ExampleModel {
    private String someField;
    private String fieldInModel;
}

和 DTO:

@Data
public class ExampleDto {
    private String someField;
    private String fieldInDto;
}

我想配置简单的映射器(使用不同的字段名称):

@Mapper(componentModel = "spring")
public interface ExampleMapper {

    @Mapping(target = "fieldInModel", source = "fieldInDto")
    ExampleModel mapToExample(ExampleDto exampleDto);
}

我的项目是一个简单的 Spring Initializr，我在其中添加了 Lombok 和 MapStruct 的配置:

...
    <properties>
        <java.version>11</java.version>
        <mapstruct.version>1.4.1.Final</mapstruct.version>
        <lombok.version>1.18.16</lombok.version>
    </properties>

    <dependencies>
        ...
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct</artifactId>
            <version>${mapstruct.version}</version>
        </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>
                <version>3.8.0</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                    <release>11</release>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.mapstruct</groupId>
                            <artifactId>mapstruct-processor</artifactId>
                            <version>${mapstruct.version}</version>
                        </path>
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                            <version>${lombok.version}</version>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

当我尝试构建它时出现错误:

No property named "fieldInDto" exists in source parameter(s). Did you mean "null"?

日志:

$ mvn clean package
...
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:compile (default-compile) on project demo: Compilation failure
[ERROR] /path/src/main/java/com/example/demo/ExampleMapper.java:[9,48] No property named "fieldInDto" exists in source parameter(s). Did you mean "null"?

$ java --version
openjdk 11.0.8 2020-07-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.8+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.8+10, mixed mode)

$ mvn -v
Apache Maven 3.5.0
Java version: 11.0.8, vendor: AdoptOpenJDK
Java home: /usr/lib/jvm/adoptopenjdk-11-hotspot-amd64

Answer 1

我能够在本地机器上重现完全相同的错误，这与您在生成 lombok 类之前使用 lombok 和 Mapstruct 来尝试生成映射有关。

解决这个问题的一种方法是在插件中确保 lombok 出现在 mapstruct 之前

<annotationProcessorPaths>
    <path>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>${lombok.version}</version>
    </path>
    <path>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct-processor</artifactId>
        <version>1.4.1.Final</version>
    </path>
</annotationProcessorPaths>

看起来 <annotationProcessorPaths>考虑到路径的顺序。

注意:如果您使用的是最新的 intellij，请不要忘记在更新订单后导入，否则您将收到相同的错误