CODEWITHSUNDEEP
javagroovybuilderauto-value
Sébastien Dubois
Sébastien Dubois

Reputation: 999

Call Groovy builder from Java

I'm trying to use Groovy (which is new to me) to replace Java value object classes with a Groovy equivalent and thus obtain a cleaner and more concise code, while remaining compatible with the rest of the Java codebase. (if this attempt fails, I may fall back to Google @AutoValue.)

The value objects shall remain instantiable from Java code using the builder pattern. The setter methods shall be without prefix and ideally the builder should be instantiable through a static method with configurable name.

@groovy.transform.builder.Builder's Javadoc mentions it can be used "if you need Java integration" and I see it also has configuration parameters which looks promising, but I did not figure out how to use it from Java code.

Here is an attempt, where I do not know what to substitute for X:

Greeting.groovy:

import groovy.transform.Immutable
import groovy.transform.builder.Builder

@Immutable
@Builder
public class GroovyGreeting {
  String message
}

GroovyGreetingTest.java:

GroovyGreeting g = X.message("foo").build();

EDIT: 2 classes are generated, target/classes/com/hello/GroovyGreeting.class and target/classes/com/hello/GroovyGreeting$com/hello/GroovyGreetingBuilder.class. The '$' in there is really strange and prevents referencing it (import com.hello.GroovyGreeting$com.hello.GroovyGreetingBuilder is illegal). Also for some reason in IntelliJ IDEA I can decompile GroovyGreetingBuilder.class but not GroovyGreeting.class (no reaction when trying to open it).

Upvotes: 5

Views: 948

Answers (1)

Controlix
Controlix

Reputation: 31

I had exactly the same problem. After investigating the code of the Builder strategies, I managed to make it work by explicitly specifying the builderClassName.

package alfa.beta

@Builder(builderClassName = 'PageLayoutBuilder')
class PageLayout

I can see that the generated builder is alfa/beta/PageLayout$PageLayoutBuilder now.

I filed a JIRA issue GROOVY-7501 for this.

Upvotes: 3

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