DATAJPA-265 - Make it possible to configure auditing with Java Config

AnnotationAuditingConfiguration.java

package org.springframework.data.auditing.config;

public interface AnnotationAuditingConfiguration {
	String getAuditorAwareRef();

	boolean isSetDates();

	String getDateTimeProviderRef();
}

AnnotationAuditingConfigurationSupport.java

package org.springframework.data.auditing.config;

import java.lang.annotation.Annotation;

import org.springframework.core.annotation.AnnotationAttributes;
import org.springframework.core.type.AnnotationMetadata;

public class AnnotationAuditingConfigurationSupport implements AnnotationAuditingConfiguration {
	protected AnnotationAttributes attributes;

	public AnnotationAuditingConfigurationSupport(AnnotationMetadata metadata, Class<? extends Annotation> annotation) {
		attributes = new AnnotationAttributes(metadata.getAnnotationAttributes(annotation.getName()));
	}

	public String getAuditorAwareRef() {
		return attributes.getString("auditorAwareRef");
	}

	public boolean isSetDates() {
		return attributes.getBoolean("setDates");
	}

	public String getDateTimeProviderRef() {
		return attributes.getString("dateTimeProviderRef");
	}
}

AuditingBeanDefinitionRegistrarSupport.java

package org.springframework.data.auditing.config;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.data.auditing.AuditingHandler;
import org.springframework.data.auditing.CurrentDateTimeProvider;
import org.springframework.util.StringUtils;

public abstract class AuditingBeanDefinitionRegistrarSupport implements ImportBeanDefinitionRegistrar {
	private final String AUDITOR_AWARE = "auditorAware";
	private final String DATE_TIME_PROVIDER = "dateTimeProvider";
	private final String SET_DATES = "dateForNow";

	public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry registry) {
		BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(AuditingHandler.class);

		AnnotationAuditingConfiguration configuration = getConfiguration(annotationMetadata);

		builder.addPropertyReference(AUDITOR_AWARE, configuration.getAuditorAwareRef());
		builder.addPropertyValue(SET_DATES, configuration.isSetDates());

		if (StringUtils.hasText(configuration.getDateTimeProviderRef())) {
			builder.addPropertyReference(DATE_TIME_PROVIDER, configuration.getDateTimeProviderRef());
		} else {
			builder.addPropertyValue(DATE_TIME_PROVIDER, CurrentDateTimeProvider.INSTANCE);
		}

		BeanDefinition auditingHandlerDefinition = builder.getBeanDefinition();

		registry.registerBeanDefinition(BeanDefinitionReaderUtils.generateBeanName(auditingHandlerDefinition, registry),
				auditingHandlerDefinition);

		postProcess(configuration, auditingHandlerDefinition, registry);

	}

	protected abstract void postProcess(AnnotationAuditingConfiguration configuration,
										BeanDefinition auditingHandlerDefinition,
										BeanDefinitionRegistry registry);

	protected abstract AnnotationAuditingConfiguration getConfiguration(AnnotationMetadata annotationMetadata);
}

EnableJpaAuditing.java

package org.springframework.data.jpa.auditing;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.context.annotation.Import;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE })
@Documented
@Inherited
@Import(JpaAuditingRegistrar.class)
public @interface EnableJpaAuditing {
	String auditorAwareRef() default "";

	boolean setDates() default true;

	String dateTimeProviderRef() default "";
}

JpaAuditingRegistrar.java

package org.springframework.data.jpa.auditing;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.data.auditing.config.AnnotationAuditingConfiguration;
import org.springframework.data.auditing.config.AnnotationAuditingConfigurationSupport;
import org.springframework.data.auditing.config.AuditingBeanDefinitionRegistrarSupport;

public class JpaAuditingRegistrar extends AuditingBeanDefinitionRegistrarSupport {

	private static final String AUDITING_ENTITY_LISTENER_CLASS_NAME = "org.springframework.data.jpa.domain.support.AuditingEntityListener";
	private static final String AUDITING_BFPP_CLASS_NAME = "org.springframework.data.jpa.domain.support.AuditingBeanFactoryPostProcessor";

	@Override
	protected AnnotationAuditingConfiguration getConfiguration(AnnotationMetadata annotationMetadata) {
		return new AnnotationAuditingConfigurationSupport(annotationMetadata, EnableJpaAuditing.class);
	}

	@Override
	protected void postProcess(AnnotationAuditingConfiguration configuration, BeanDefinition auditingHandlerDefinition, BeanDefinitionRegistry registry) {
		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(AUDITING_ENTITY_LISTENER_CLASS_NAME);
		builder.addPropertyValue("auditingHandler", auditingHandlerDefinition);
		builder.setScope("prototype");

		registerInfrastructureBeans(builder.getBeanDefinition(), AUDITING_ENTITY_LISTENER_CLASS_NAME, registry);

		RootBeanDefinition def = new RootBeanDefinition(AUDITING_BFPP_CLASS_NAME);
		registerInfrastructureBeans(def, AUDITING_BFPP_CLASS_NAME, registry);

	}

	private void registerInfrastructureBeans(AbstractBeanDefinition definition, String id, BeanDefinitionRegistry registry) {
		definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
		registry.registerBeanDefinition(id, definition);
	}
}