DATACMNS-47 - Add support for JavaConfig based repository configuration.

Completely rewrote namespace bean definition parsing to be extendable more easily. Separated XML concerns from annotation based configuration. The central point to extend the namespace parsing for a certain module is now hidden behind the RepositoryConfigurationExtension interface (have a look at the RepositoryConfigurationExtensionSupport base class as well).

spring-data-commons-core/src/main/java/org/springframework/data/repository/config/AnnotationRepositoryConfigurationSource.java

@@ -0,0 +1,220 @@
+/*
+ * Copyright 2012 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.repository.config;
+
+import java.lang.annotation.Annotation;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.context.annotation.FilterType;
+import org.springframework.core.annotation.AnnotationAttributes;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.core.type.filter.AnnotationTypeFilter;
+import org.springframework.core.type.filter.AssignableTypeFilter;
+import org.springframework.core.type.filter.TypeFilter;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
+
+/**
+ * Annotation based {@link RepositoryConfigurationSource}.
+ * 
+ * @author Oliver Gierke
+ */
+public class AnnotationRepositoryConfigurationSource extends RepositoryConfigurationSourceSupport {
+
+	private static final String REPOSITORY_IMPLEMENTATION_POSTFIX = "repositoryImplementationPostfix";
+	private static final String BASE_PACKAGES = "basePackages";
+	private static final String BASE_PACKAGE_CLASSES = "basePackageClasses";
+	private static final String NAMED_QUERIES_LOCATION = "namedQueriesLocation";
+	private static final String QUERY_LOOKUP_STRATEGY = "queryLookupStrategy";
+	private static final String REPOSITORY_FACTORY_BEAN_CLASS = "repositoryFactoryBeanClass";
+
+	private final AnnotationMetadata metadata;
+	private final AnnotationAttributes attributes;
+
+	/**
+	 * Creates a new {@link AnnotationRepositoryConfigurationSource} from the given {@link AnnotationMetadata} and
+	 * annotation.
+	 * 
+	 * @param metadata must not be {@literal null}.
+	 * @param annotation must not be {@literal null}.
+	 */
+	public AnnotationRepositoryConfigurationSource(AnnotationMetadata metadata, Class<? extends Annotation> annotation) {
+
+		Assert.notNull(metadata);
+		Assert.notNull(annotation);
+
+		this.attributes = new AnnotationAttributes(metadata.getAnnotationAttributes(annotation.getName()));
+		this.metadata = metadata;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getBasePackages()
+	 */
+	public Iterable<String> getBasePackages() {
+
+		String[] value = attributes.getStringArray("value");
+		String[] basePackages = attributes.getStringArray(BASE_PACKAGES);
+		Class<?>[] basePackageClasses = attributes.getClassArray(BASE_PACKAGE_CLASSES);
+
+		// Default configuration - return package of annotated class
+		if (value.length == 0 && basePackages.length == 0 && basePackageClasses.length == 0) {
+			String className = metadata.getClassName();
+			return Collections.singleton(className.substring(0, className.lastIndexOf('.')));
+		}
+
+		Set<String> packages = new HashSet<String>();
+		packages.addAll(Arrays.asList(value));
+		packages.addAll(Arrays.asList(basePackages));
+
+		for (Class<?> typeName : basePackageClasses) {
+			packages.add(ClassUtils.getPackageName(typeName));
+		}
+
+		return packages;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getQueryLookupStrategyKey()
+	 */
+	public Object getQueryLookupStrategyKey() {
+		return attributes.get(QUERY_LOOKUP_STRATEGY);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getNamedQueryLocation()
+	 */
+	public String getNamedQueryLocation() {
+		return getNullDefaultedAttribute(NAMED_QUERIES_LOCATION);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryImplementationPostfix()
+	 */
+	public String getRepositoryImplementationPostfix() {
+		return getNullDefaultedAttribute(REPOSITORY_IMPLEMENTATION_POSTFIX);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getSource()
+	 */
+	public Object getSource() {
+		return metadata;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSourceSupport#getIncludeFilters()
+	 */
+	@Override
+	protected Iterable<TypeFilter> getIncludeFilters() {
+		return parseFilters("includeFilters");
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSourceSupport#getExcludeFilters()
+	 */
+	@Override
+	protected Iterable<TypeFilter> getExcludeFilters() {
+		return parseFilters("excludeFilters");
+	}
+
+	private Set<TypeFilter> parseFilters(String attributeName) {
+
+		Set<TypeFilter> result = new HashSet<TypeFilter>();
+		AnnotationAttributes[] filters = attributes.getAnnotationArray(attributeName);
+
+		for (AnnotationAttributes filter : filters) {
+			result.addAll(typeFiltersFor(filter));
+		}
+
+		return result;
+	}
+
+	/**
+	 * Returns the {@link String} attribute with the given name and defaults it to {@literal null} in case it's empty.
+	 * 
+	 * @param attributeName
+	 * @return
+	 */
+	private String getNullDefaultedAttribute(String attributeName) {
+		String attribute = attributes.getString(attributeName);
+		return StringUtils.hasText(attribute) ? attribute : null;
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.config.RepositoryConfigurationSource#getRepositoryFactoryBeanName()
+	 */
+	public String getRepositoryFactoryBeanName() {
+		return attributes.getClass(REPOSITORY_FACTORY_BEAN_CLASS).getName();
+	}
+
+	/**
+	 * Returns the {@link AnnotationAttributes} of the annotation configured.
+	 * 
+	 * @return the attributes will never be {@literal null}.
+	 */
+	public AnnotationAttributes getAttributes() {
+		return attributes;
+	}
+
+	/**
+	 * Copy of {@code ComponentScanAnnotationParser#typeFiltersFor}.
+	 * 
+	 * @param filterAttributes
+	 * @return
+	 */
+	private List<TypeFilter> typeFiltersFor(AnnotationAttributes filterAttributes) {
+		List<TypeFilter> typeFilters = new ArrayList<TypeFilter>();
+		FilterType filterType = filterAttributes.getEnum("type");
+
+		for (Class<?> filterClass : filterAttributes.getClassArray("value")) {
+			switch (filterType) {
+			case ANNOTATION:
+				Assert.isAssignable(Annotation.class, filterClass, "An error occured when processing a @ComponentScan "
+						+ "ANNOTATION type filter: ");
+				@SuppressWarnings("unchecked")
+				Class<Annotation> annoClass = (Class<Annotation>) filterClass;
+				typeFilters.add(new AnnotationTypeFilter(annoClass));
+				break;
+			case ASSIGNABLE_TYPE:
+				typeFilters.add(new AssignableTypeFilter(filterClass));
+				break;
+			case CUSTOM:
+				Assert.isAssignable(TypeFilter.class, filterClass, "An error occured when processing a @ComponentScan "
+						+ "CUSTOM type filter: ");
+				typeFilters.add(BeanUtils.instantiateClass(filterClass, TypeFilter.class));
+				break;
+			default:
+				throw new IllegalArgumentException("unknown filter type " + filterType);
+			}
+		}
+		return typeFilters;
+	}
+}