AnnotationProcessor and dependencies - gradle

Question

I'm using gradle / querydsl and JPA 2.1.
I would like to generate the querydsl metadata using APT (QEntities).
To do that I'm using the gradle-apt-plugin and gradle 4.7
In my project I configured the compileJava option using :
compileJava {
options.annotationProcessorGeneratedSourcesDirectory = file("$projectDir/src/generated2/java")
}
In my dependencies I added
compile 'org.springframework.boot:spring-boot-starter-data-jpa'"
annotationProcessor "com.querydsl:querydsl-apt:$querydslVersion:jpa"
The spring starter adds the org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final jar that contains javax.persistence.Entity class to the compileClasspath.
When launching the compileJava task I got the error :
caused by: java.lang.NoClassDefFoundError: javax/persistence/Entity at com.querydsl.apt.jpa.JPAAnnotationProcessor.createConfiguration(JPAAnnotationProcessor.java:37)
Don't understand why the annotation processor cannot load this class.

Answer 1

In case somebody else is searching. This is my full solution (based on your response). The important parts are the net.ltgt.apt* plugins to activate the code generation also in eclipse, and the last three querydsl dependencies.
buildscript {
ext {
springBootVersion = '2.0.5.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
plugins { // activates the automatic code generation
id 'net.ltgt.apt' version '0.18'
id 'net.ltgt.apt-eclipse' version '0.18'
}
apply plugin: 'java'
apply plugin: 'eclipse-wtp'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'
apply plugin: 'war'
group = 'com.test'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
configurations {
providedRuntime
}
dependencies {
runtimeOnly 'com.h2database:h2'
implementation 'org.springframework.boot:spring-boot-starter-actuator'
implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
implementation 'org.springframework.boot:spring-boot-starter-web'
providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'org.springframework.boot:spring-boot-starter-webflux'
// querydsl
annotationProcessor 'com.querydsl:querydsl-apt:4.1.3:jpa'
annotationProcessor 'org.springframework.boot:spring-boot-starter-data-jpa' // needed because the query dsl annotation processor doesn't recognize javax.persistence.Entity
compile 'com.querydsl:querydsl-jpa:4.1.3'
}