Lombok @Builder 在 lombok-1.16.18 java 中不起作用：找不到符号 builderclass

Question

@Builder
public class ProcessorLombokBO {
    private String panel;
    private String motherBoard;
    private String ram;
    private String hardDisk;
}

public static void main(String[] args) {
    ProcessorLombokBO processorLombokBO =
                    new ProcessorLombokBO.ProcessorLombokBOBuilder()
                    .panel("Brown")
                    .hardDisk("SanDisk 256GB")
                    .ram("4GB")
                    .motherBoard("Intel")
                    .build();
    System.out.println(processorLombokBO);
}

I am trying to implemenent @Builder in a POJO, but it gives the below error when I execute the main method.

java: cannot find symbol symbol: class ProcessorLombokBOBuilder

Did I miss something?

Answer 1

Edit: Try making your inner ProcessorLombokBO class static. You can't use Builder on an inner non-static class, as the compile error at your example suggests in my IDE (Eclipse)

The method builder cannot be declared static; static methods can only be declared in a static or top level type

The reason is that @Builder generates an inner static class (the ProcessorLombokBOBuilder class) and adds a static method builder() , which is by specification only possible if the outer class is also static, because else you need an enclosing instance to reference the Builder class, which contradicts the concept of a static type.

Original Post: Usually you instanciate your Builder via

ProcessorLombokBO.builder()

Answer 2

I had this same issue and found that @Builder support was disabled in IntelliJ:

Answer 3

If you are using mapstruct-processor plugin in your Maven project, it will affect the builder method.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.5.1</version>
    <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>

Answer 4

Try adding the following entry to your POM, it helped in my case:

                       <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>
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok-mapstruct-binding</artifactId>
                            <version>0.2.0</version>
                        </path>
                    </annotationProcessorPaths>