DATALDAP-5 - Add CDI extension for LDAP repositories.

We now provide a CDI extension to create LDAP repositories in a CDI container. LDAP repositories require a LdapOperations bean as underlying resource manager for LDAP access.

class LdapTemplateProducer {

  @Produces
  @Singleton
  public LdapTemplate createLdapTemplate() {

    LdapTemplate ldapTemplateMock = …
    return ldapTemplateMock;
  }
}

class RepositoryClient {

  @Inject
  PersonRepository repository;
}

src/main/java/org/springframework/data/ldap/repository/cdi/LdapRepositoryBean.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.ldap.repository.cdi;
+
+import java.lang.annotation.Annotation;
+import java.util.Optional;
+import java.util.Set;
+
+import javax.enterprise.context.spi.CreationalContext;
+import javax.enterprise.inject.spi.Bean;
+import javax.enterprise.inject.spi.BeanManager;
+
+import org.springframework.data.ldap.repository.support.LdapRepositoryFactory;
+import org.springframework.data.repository.cdi.CdiRepositoryBean;
+import org.springframework.data.repository.config.CustomRepositoryImplementationDetector;
+import org.springframework.ldap.core.LdapOperations;
+import org.springframework.util.Assert;
+
+/**
+ * {@link CdiRepositoryBean} to create LDAP repository instances.
+ *
+ * @author Mark Paluch
+ * @since 2.1
+ */
+public class LdapRepositoryBean<T> extends CdiRepositoryBean<T> {
+
+	private final Bean<LdapOperations> operations;
+
+	/**
+	 * Creates a new {@link LdapRepositoryBean}.
+	 *
+	 * @param operations must not be {@literal null}.
+	 * @param qualifiers must not be {@literal null}.
+	 * @param repositoryType must not be {@literal null}.
+	 * @param beanManager must not be {@literal null}.
+	 * @param detector detector for the custom {@link org.springframework.data.repository.Repository} implementations
+	 *          {@link CustomRepositoryImplementationDetector}, can be {@link Optional#empty()}.
+	 */
+	LdapRepositoryBean(Bean<LdapOperations> operations, Set<Annotation> qualifiers, Class<T> repositoryType,
+			BeanManager beanManager, Optional<CustomRepositoryImplementationDetector> detector) {
+
+		super(qualifiers, repositoryType, beanManager, detector);
+
+		Assert.notNull(operations, "LdapOperations bean must not be null!");
+		this.operations = operations;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.cdi.CdiRepositoryBean#create(javax.enterprise.context.spi.CreationalContext, java.lang.Class)
+	 */
+	@Override
+	protected T create(CreationalContext<T> creationalContext, Class<T> repositoryType,
+			Optional<Object> customImplementation) {
+
+		LdapOperations ldapOperations = getDependencyInstance(operations, LdapOperations.class);
+		LdapRepositoryFactory factory = new LdapRepositoryFactory(ldapOperations);
+
+		return customImplementation.map(o -> factory.getRepository(repositoryType, o))
+				.orElseGet(() -> factory.getRepository(repositoryType));
+	}
+}

src/main/java/org/springframework/data/ldap/repository/cdi/LdapRepositoryExtension.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.ldap.repository.cdi;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.Set;
+
+import javax.enterprise.event.Observes;
+import javax.enterprise.inject.UnsatisfiedResolutionException;
+import javax.enterprise.inject.spi.AfterBeanDiscovery;
+import javax.enterprise.inject.spi.Bean;
+import javax.enterprise.inject.spi.BeanManager;
+import javax.enterprise.inject.spi.ProcessBean;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.data.repository.cdi.CdiRepositoryBean;
+import org.springframework.data.repository.cdi.CdiRepositoryExtensionSupport;
+import org.springframework.ldap.core.LdapOperations;
+
+/**
+ * CDI extension to export LDAP repositories.
+ *
+ * @author Mark Paluch
+ * @since 2.1
+ */
+public class LdapRepositoryExtension extends CdiRepositoryExtensionSupport {
+
+	private static final Logger LOG = LoggerFactory.getLogger(LdapRepositoryExtension.class);
+
+	private final Map<Set<Annotation>, Bean<LdapOperations>> ldapOperations = new HashMap<>();
+
+	public LdapRepositoryExtension() {
+		LOG.info("Activating CDI extension for Spring Data LDAP repositories.");
+	}
+
+	@SuppressWarnings("unchecked")
+	<X> void processBean(@Observes ProcessBean<X> processBean) {
+
+		Bean<X> bean = processBean.getBean();
+
+		for (Type type : bean.getTypes()) {
+			if (type instanceof Class<?> && LdapOperations.class.isAssignableFrom((Class<?>) type)) {
+				if (LOG.isDebugEnabled()) {
+					LOG.debug(
+							String.format("Discovered %s with qualifiers %s.", LdapOperations.class.getName(), bean.getQualifiers()));
+				}
+
+				// Store the EntityManager bean using its qualifiers.
+				ldapOperations.put(new HashSet<>(bean.getQualifiers()), (Bean<LdapOperations>) bean);
+			}
+		}
+	}
+
+	void afterBeanDiscovery(@Observes AfterBeanDiscovery afterBeanDiscovery, BeanManager beanManager) {
+
+		for (Entry<Class<?>, Set<Annotation>> entry : getRepositoryTypes()) {
+
+			Class<?> repositoryType = entry.getKey();
+			Set<Annotation> qualifiers = entry.getValue();
+
+			// Create the bean representing the repository.
+			CdiRepositoryBean<?> repositoryBean = createRepositoryBean(repositoryType, qualifiers, beanManager);
+
+			if (LOG.isInfoEnabled()) {
+				LOG.info(String.format("Registering bean for %s with qualifiers %s.", repositoryType.getName(), qualifiers));
+			}
+
+			// Register the bean to the container.
+			registerBean(repositoryBean);
+			afterBeanDiscovery.addBean(repositoryBean);
+		}
+	}
+
+	/**
+	 * Creates a {@link CdiRepositoryBean} for the repository of the given type.
+	 *
+	 * @param <T> the type of the repository.
+	 * @param repositoryType the class representing the repository.
+	 * @param qualifiers the qualifiers to be applied to the bean.
+	 * @param beanManager the BeanManager instance.
+	 * @return the repository bean.
+	 */
+	private <T> CdiRepositoryBean<T> createRepositoryBean(Class<T> repositoryType, Set<Annotation> qualifiers,
+			BeanManager beanManager) {
+
+		// Determine the LdapOperations bean which matches the qualifiers of the repository.
+		Bean<LdapOperations> LdapOperations = this.ldapOperations.get(qualifiers);
+
+		if (LdapOperations == null) {
+			throw new UnsatisfiedResolutionException(String.format("Unable to resolve a bean for '%s' with qualifiers %s.",
+					LdapOperations.class.getName(), qualifiers));
+		}
+
+		// Construct and return the repository bean.
+		return new LdapRepositoryBean<>(LdapOperations, qualifiers, repositoryType, beanManager,
+				Optional.of(getCustomImplementationDetector()));
+	}
+}

src/main/java/org/springframework/data/ldap/repository/cdi/package-info.java

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+/**
+ * CDI support for LDAP specific repository implementation.
+ */
+@org.springframework.lang.NonNullApi
+package org.springframework.data.ldap.repository.cdi;