Java tutorial
package org.ff4j.spring.placeholder; /* * #%L * ff4j-aop * %% * Copyright (C) 2013 - 2015 Ff4J * %% * 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. * #L% */ import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import org.ff4j.FF4j; import org.ff4j.core.Feature; import org.ff4j.exception.FeatureNotFoundException; import org.ff4j.exception.PropertyNotFoundException; import org.ff4j.property.Property; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.BeansException; import org.springframework.beans.factory.BeanDefinitionStoreException; import org.springframework.beans.factory.config.BeanDefinitionVisitor; /** * Pattern Bean Visitor. * * @author <a href="mailto:cedrick.lunven@gmail.com">Cedrick LUNVEN</a> */ public class PropertiesPlaceHolderBeanDefinitionVisitor extends BeanDefinitionVisitor { /** Static commons-log LOG for this class. * */ private static final Logger LOGGER = LoggerFactory.getLogger(PropertiesPlaceHolderBeanDefinitionVisitor.class); /** Properties Map from store **/ private Map<String, Property<?>> propertiesMap = new HashMap<String, Property<?>>(); /** Properties Map from store **/ private Map<String, Feature> featuresMap = new HashMap<String, Feature>(); /** Prefix to every registry stored adress. * */ public static final String PLACEHOLDER_PROPERTY_PREFIX = "@ff4jProperty{"; /** Prefix to every registry stored adress. * */ public static final String PLACEHOLDER_FEATURE_PREFIX = "@ff4jFeature{"; /** Prefix to every registry stored adress. * */ public static final String PLACEHOLDER_SUFFIX = "}"; /** * Instanciate visitor. * @param serviceMap * parameter service map */ public PropertiesPlaceHolderBeanDefinitionVisitor(FF4j ff4j) { if (ff4j == null) { throw new IllegalArgumentException("Cannot initialize placeholding 'ff4j' is null"); } this.propertiesMap = ff4j.getProperties(); this.featuresMap = ff4j.getFeatures(); } /** {@inheritDoc} */ protected String resolveStringValue(String strVal) throws BeansException { return parseStringValue(strVal, propertiesMap, featuresMap, new HashSet<String>()); } /** * Parsing value to handle * @param strVal * @param uriMap * @param visitedPlaceholders * @return * @throws BeanDefinitionStoreException */ protected String parseStringValue(String strVal, Map<String, Property<?>> propertiesMap, Map<String, Feature> featureMap, Set<String> visitedPlaceholders) throws BeanDefinitionStoreException { StringBuilder builder = new StringBuilder(strVal); // @ff4jProperty{} int startIndex = strVal.indexOf(PLACEHOLDER_PROPERTY_PREFIX); while (startIndex != -1) { int endIndex = builder.toString().indexOf(PLACEHOLDER_SUFFIX, startIndex + PLACEHOLDER_PROPERTY_PREFIX.length()); if (endIndex != -1) { String placeholder = builder.substring(startIndex + PLACEHOLDER_PROPERTY_PREFIX.length(), endIndex); if (!visitedPlaceholders.add(placeholder)) { throw new BeanDefinitionStoreException( "Circular placeholder reference '" + placeholder + "' in property definitions"); } if (propertiesMap == null || !propertiesMap.containsKey(placeholder)) { throw new PropertyNotFoundException( PLACEHOLDER_PROPERTY_PREFIX + ": Cannot perform placeholding on " + placeholder); } String propVal = propertiesMap.get(placeholder).asString(); if (propVal != null) { propVal = parseStringValue(propVal, propertiesMap, featureMap, visitedPlaceholders); builder.replace(startIndex, endIndex + PLACEHOLDER_SUFFIX.length(), propVal); if (LOGGER.isDebugEnabled()) { LOGGER.debug("Resolved placeholder '{}' to value '{}'", placeholder, propVal); } startIndex = builder.toString().indexOf(PLACEHOLDER_PROPERTY_PREFIX, startIndex + propVal.length()); } else { throw new BeanDefinitionStoreException("Could not resolve placeholder '" + placeholder + "'"); } visitedPlaceholders.remove(placeholder); } else { startIndex = -1; } } // @ff4jFeature{} startIndex = strVal.indexOf(PLACEHOLDER_FEATURE_PREFIX); while (startIndex != -1) { int endIndex = builder.toString().indexOf(PLACEHOLDER_SUFFIX, startIndex + PLACEHOLDER_FEATURE_PREFIX.length()); if (endIndex != -1) { String placeholder = builder.substring(startIndex + PLACEHOLDER_FEATURE_PREFIX.length(), endIndex); if (!visitedPlaceholders.add(placeholder)) { throw new BeanDefinitionStoreException( "Circular placeholder reference '" + placeholder + "' in property definitions"); } if (featureMap == null || !featureMap.containsKey(placeholder)) { throw new FeatureNotFoundException( PLACEHOLDER_FEATURE_PREFIX + ": Cannot perform placeholding on " + placeholder); } String propVal = String.valueOf(featureMap.get(placeholder).isEnable()); if (propVal != null) { propVal = parseStringValue(propVal, propertiesMap, featureMap, visitedPlaceholders); builder.replace(startIndex, endIndex + PLACEHOLDER_FEATURE_PREFIX.length(), propVal); if (LOGGER.isDebugEnabled()) { LOGGER.debug("Resolved placeholder '{}' to value '{}'", placeholder, propVal); } startIndex = builder.toString().indexOf(PLACEHOLDER_FEATURE_PREFIX, startIndex + propVal.length()); } else { throw new BeanDefinitionStoreException("Could not resolve placeholder '" + placeholder + "'"); } visitedPlaceholders.remove(placeholder); } else { startIndex = -1; } } return builder.toString(); } }