Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.sling.contextaware.config.impl; import static org.apache.sling.contextaware.config.impl.ConfigurationNameConstants.CONFIGS_PARENT_NAME; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import org.apache.commons.lang3.StringUtils; import org.apache.sling.api.resource.Resource; import org.apache.sling.api.resource.ResourceUtil; import org.apache.sling.api.resource.ValueMap; import org.apache.sling.contextaware.config.ConfigurationBuilder; import org.apache.sling.contextaware.config.ConfigurationResolveException; import org.apache.sling.contextaware.config.ConfigurationResolver; import org.apache.sling.contextaware.config.impl.ConfigurationProxy.ChildResolver; import org.apache.sling.contextaware.config.impl.metadata.AnnotationClassParser; import org.apache.sling.contextaware.config.resource.ConfigurationResourceResolver; import org.apache.sling.contextaware.config.spi.ConfigurationPersistenceStrategy; class ConfigurationBuilderImpl implements ConfigurationBuilder { private final Resource contentResource; private final ConfigurationResolver configurationResolver; private final ConfigurationResourceResolver configurationResourceResolver; private final ConfigurationPersistenceStrategy configurationPersistenceStrategy; private String configName; public ConfigurationBuilderImpl(final Resource resource, final ConfigurationResolver configurationResolver, final ConfigurationResourceResolver configurationResourceResolver, final ConfigurationPersistenceStrategy configurationPersistenceStrategy) { this.contentResource = resource; this.configurationResolver = configurationResolver; this.configurationResourceResolver = configurationResourceResolver; this.configurationPersistenceStrategy = configurationPersistenceStrategy; } @Override public ConfigurationBuilder name(String configName) { if (!isNameValid(configName)) { throw new IllegalArgumentException("Invalid configuration name: " + configName); } this.configName = configName; return this; } /** * Check the name. * A name must not be null and relative. * @param name The name * @return {@code true} if it is valid */ private boolean isNameValid(final String name) { return !StringUtils.isBlank(name) && !StringUtils.startsWith(name, "/") && !StringUtils.contains(name, "../"); } /** * Validate the configuration name. * @param name Configuration name or relative path */ private void validateConfigurationName(String name) { if (name == null) { throw new ConfigurationResolveException("Configuration name is required."); } } /** * Converts configuration resource into given class. * @param <T> Target class */ private interface Converter<T> { T convert(Resource resource, Class<T> clazz, String name); } /** * Get singleton configuration resource and convert it to the desired target class. * @param name Configuration name * @param clazz Target class * @param converter Conversion method * @return Converted singleton configuration */ private <T> T getConfigResource(String name, Class<T> clazz, Converter<T> converter) { Resource configResource = null; if (this.contentResource != null) { validateConfigurationName(name); configResource = this.configurationResourceResolver.getResource(this.contentResource, CONFIGS_PARENT_NAME, name); } return convert(configResource, clazz, converter, name); } /** * Get configuration resource collection and convert it to the desired target class. * @param name Configuration name * @param clazz Target class * @param converter Conversion method * @return Converted configuration collection */ private <T> Collection<T> getConfigResourceCollection(String name, Class<T> clazz, Converter<T> converter) { if (this.contentResource != null) { validateConfigurationName(name); final Collection<T> result = new ArrayList<>(); for (final Resource rsrc : this.configurationResourceResolver .getResourceCollection(this.contentResource, CONFIGS_PARENT_NAME, name)) { final T obj = convert(rsrc, clazz, converter, name + "/" + rsrc.getName()); if (obj != null) { result.add(obj); } } return result; } else { return Collections.emptyList(); } } private <T> T convert(Resource resource, Class<T> clazz, Converter<T> converter, String name) { Resource configResource = null; if (resource != null) { configResource = configurationPersistenceStrategy.getResource(resource); } return converter.convert(configResource, clazz, name); } // --- Annotation class support --- @Override public <T> T as(final Class<T> clazz) { final String name = getConfigurationNameForAnnotationClass(clazz); return getConfigResource(name, clazz, new AnnotationConverter<T>()); } @Override public <T> Collection<T> asCollection(Class<T> clazz) { final String name = getConfigurationNameForAnnotationClass(clazz); return getConfigResourceCollection(name, clazz, new AnnotationConverter<T>()); } private String getConfigurationNameForAnnotationClass(Class<?> clazz) { if (this.configName != null) { return this.configName; } else { // derive configuration name from annotation class if no name specified return AnnotationClassParser.getConfigurationName(clazz); } } private class AnnotationConverter<T> implements Converter<T> { @Override public T convert(final Resource resource, final Class<T> clazz, final String name) { return ConfigurationProxy.get(resource, clazz, new ChildResolver() { private ConfigurationBuilder getConfiguration(String configName) { String childName = name + "/" + configName; return configurationResolver.get(contentResource).name(childName); } @Override public <C> C getChild(String configName, Class<C> clazz) { return getConfiguration(configName).as(clazz); } @Override public <C> Collection<C> getChildren(String configName, Class<C> clazz) { return getConfiguration(configName).asCollection(clazz); } }); } } // --- ValueMap support --- @Override public ValueMap asValueMap() { return getConfigResource(this.configName, ValueMap.class, new ValueMapConverter()); } @Override public Collection<ValueMap> asValueMapCollection() { return getConfigResourceCollection(this.configName, ValueMap.class, new ValueMapConverter()); } private static class ValueMapConverter implements Converter<ValueMap> { @Override public ValueMap convert(Resource resource, Class<ValueMap> clazz, String name) { return ResourceUtil.getValueMap(resource); } } // --- Adaptable support --- @Override public <T> T asAdaptable(Class<T> clazz) { return getConfigResource(this.configName, clazz, new AdaptableConverter<T>()); } @Override public <T> Collection<T> asAdaptableCollection(Class<T> clazz) { return getConfigResourceCollection(this.configName, clazz, new AdaptableConverter<T>()); } private static class AdaptableConverter<T> implements Converter<T> { @Override public T convert(Resource resource, Class<T> clazz, String name) { if (resource == null || clazz == ConfigurationBuilder.class) { return null; } return resource.adaptTo(clazz); } } }