001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.blueprint;
018    
019    import java.lang.reflect.Method;
020    import java.util.ArrayList;
021    import java.util.LinkedHashSet;
022    import java.util.List;
023    import java.util.Map;
024    import java.util.Properties;
025    import java.util.Set;
026    
027    import org.apache.aries.blueprint.ExtendedBeanMetadata;
028    import org.apache.aries.blueprint.ext.AbstractPropertyPlaceholder;
029    import org.apache.aries.blueprint.ext.PropertyPlaceholder;
030    import org.apache.camel.component.properties.DefaultPropertiesParser;
031    import org.apache.camel.component.properties.PropertiesComponent;
032    import org.apache.camel.component.properties.PropertiesParser;
033    import org.apache.camel.util.ObjectHelper;
034    import org.osgi.service.blueprint.container.BlueprintContainer;
035    import org.osgi.service.blueprint.reflect.ComponentMetadata;
036    
037    /**
038     * Blueprint {@link PropertiesParser} which supports looking up
039     * property placeholders from the Blueprint Property Placeholder Service.
040     * <p/>
041     * This implementation will sit on top of any existing configured
042     * {@link PropertiesParser} and will delegate to those in case Blueprint could not
043     * resolve the property.
044     */
045    public class BlueprintPropertiesParser extends DefaultPropertiesParser {
046    
047        private final PropertiesComponent propertiesComponent;
048        private final BlueprintContainer container;
049        private final PropertiesParser delegate;
050        private final Set<AbstractPropertyPlaceholder> placeholders = new LinkedHashSet<AbstractPropertyPlaceholder>();
051        private Method method;
052    
053        public BlueprintPropertiesParser(PropertiesComponent propertiesComponent, BlueprintContainer container, PropertiesParser delegate) {
054            this.propertiesComponent = propertiesComponent;
055            this.container = container;
056            this.delegate = delegate;
057        }
058    
059        /**
060         * Lookup the ids of the Blueprint property placeholder services in the
061         * Blueprint container.
062         *
063         * @return the ids, will be an empty array if none found.
064         */
065        public String[] lookupPropertyPlaceholderIds() {
066            List<String> ids = new ArrayList<String>();
067    
068            for (Object componentId : container.getComponentIds()) {
069                String id = (String) componentId;
070                ComponentMetadata meta = container.getComponentMetadata(id);
071                if (meta instanceof ExtendedBeanMetadata) {
072                    Class<?> clazz = ((ExtendedBeanMetadata) meta).getRuntimeClass();
073                    if (clazz != null && AbstractPropertyPlaceholder.class.isAssignableFrom(clazz)) {
074                        ids.add(id);
075                    }
076                }
077            }
078    
079            return ids.toArray(new String[ids.size()]);
080        }
081    
082        /**
083         * Adds the given Blueprint property placeholder service with the given id
084         *
085         * @param id id of the Blueprint property placeholder service to add.
086         */
087        public void addPropertyPlaceholder(String id) {
088            Object component = container.getComponentInstance(id);
089    
090            if (component instanceof AbstractPropertyPlaceholder) {
091                AbstractPropertyPlaceholder placeholder = (AbstractPropertyPlaceholder) component;
092                placeholders.add(placeholder);
093    
094                log.debug("Adding Blueprint PropertyPlaceholder: {}", id);
095    
096                if (method == null) {
097                    try {
098                        method = AbstractPropertyPlaceholder.class.getDeclaredMethod("getProperty", String.class);
099                        method.setAccessible(true);
100                    } catch (NoSuchMethodException e) {
101                        throw new IllegalStateException("Cannot add blueprint property placeholder: " + id
102                                + " as the method getProperty is not accessible", e);
103                    }
104                }
105            }
106        }
107    
108        @Override
109        public String parseProperty(String key, String value, Properties properties) {
110            log.trace("Parsing property key: {} with value: {}", key, value);
111    
112            String answer = null;
113    
114            // prefer any override properties
115            // this logic is special for BlueprintPropertiesParser as we otherwise prefer
116            // to use the AbstractPropertyPlaceholder from OSGi blueprint config admins
117            // service to lookup otherwise
118            if (key != null && propertiesComponent.getOverrideProperties() != null) {
119                answer = (String) propertiesComponent.getOverrideProperties().get(key);
120            }
121    
122            // lookup key in blueprint and return its value
123            if (answer == null && key != null) {
124                for (AbstractPropertyPlaceholder placeholder : placeholders) {
125    
126                    boolean isDefault = false;
127                    if (placeholders.size() > 1) {
128                        // okay we have multiple placeholders and we want to return the answer that
129                        // is not the default placeholder if there is multiple keys
130                        if (placeholder instanceof PropertyPlaceholder) {
131                            Map map = ((PropertyPlaceholder) placeholder).getDefaultProperties();
132                            isDefault = map != null && map.containsKey(key);
133                        }
134                        log.trace("Blueprint property key: {} is part of default properties: {}", key, isDefault);
135                    }
136    
137                    String candidate = (String) ObjectHelper.invokeMethod(method, placeholder, key);
138    
139                    if (candidate != null) {
140                        if (answer == null || !isDefault) {
141                            log.trace("Blueprint parsed candidate property key: {} as value: {}", key, answer);
142                            answer = candidate;
143                        }
144                    }
145                }
146    
147                log.debug("Blueprint parsed property key: {} as value: {}", key, answer);
148            }
149    
150            // if there is a delegate then let it parse the current answer as it may be jasypt which
151            // need to decrypt values
152            if (delegate != null) {
153                String delegateAnswer = delegate.parseProperty(key, answer != null ? answer : value, properties);
154                if (delegateAnswer != null) {
155                    answer = delegateAnswer;
156                }
157            }
158    
159            log.trace("Returning parsed property key: {} as value: {}", key, answer);
160            return answer;
161        }
162    
163    }