001    /*
002     * Copyright (C) 2012 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    
020    package org.crsh.plugin;
021    
022    import java.util.HashMap;
023    import java.util.Map;
024    import java.util.logging.Level;
025    import java.util.logging.Logger;
026    
027    /** @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> */
028    class PropertyManager {
029    
030      /** . */
031      private static final Logger log = Logger.getLogger(PropertyManager.class.getName());
032    
033      /** . */
034      private final Map<String, Property<?>> properties;
035    
036      PropertyManager() {
037        this.properties = new HashMap<String, Property<?>>();
038      }
039    
040      /**
041       * Returns a context property or null if it cannot be found.
042       *
043       * @param desc the property descriptor
044       * @param <T> the property parameter type
045       * @return the property value
046       * @throws NullPointerException if the descriptor argument is null
047       */
048      public <T> Property<T> getProperty(PropertyDescriptor<T> desc) throws NullPointerException {
049        if (desc == null) {
050          throw new NullPointerException();
051        }
052        return getProperty(desc.getName(), desc.getType());
053      }
054    
055      /**
056       * Returns a context property or null if it cannot be found.
057       *
058       * @param propertyName the name of the property
059       * @param type the property type
060       * @param <T> the property parameter type
061       * @return the property value
062       * @throws NullPointerException if the descriptor argument is null
063       */
064      <T> Property<T> getProperty(String propertyName, Class<T> type) throws NullPointerException {
065        if (propertyName == null) {
066          throw new NullPointerException("No null property name accepted");
067        }
068        if (type == null) {
069          throw new NullPointerException("No null property type accepted");
070        }
071        Property<?> property = properties.get(propertyName);
072        if (property != null) {
073          PropertyDescriptor<?> descriptor = property.getDescriptor();
074          if (type.equals(descriptor.getType())) {
075            return (Property<T>)property;
076          }
077        }
078        return null;
079      }
080    
081      /**
082       * Returns a context property value or null if it cannot be found.
083       *
084       * @param desc the property descriptor
085       * @param <T> the property parameter type
086       * @return the property value
087       * @throws NullPointerException if the descriptor argument is null
088       */
089      public <T> T resolvePropertyValue(PropertyDescriptor<T> desc) throws NullPointerException {
090        if (desc == null) {
091          throw new NullPointerException();
092        }
093        return resolvePropertyValue(desc.getName(), desc.getType());
094      }
095    
096      /**
097       * Returns a context property value or null if it cannot be found.
098       *
099       * @param propertyName the name of the property
100       * @param type the property type
101       * @param <T> the property parameter type
102       * @return the property value
103       * @throws NullPointerException if the descriptor argument is null
104       */
105      <T> T resolvePropertyValue(String propertyName, Class<T> type) throws NullPointerException {
106        if (propertyName == null) {
107          throw new NullPointerException("No null property name accepted");
108        }
109        if (type == null) {
110          throw new NullPointerException("No null property type accepted");
111        }
112        Property<? extends T> property = resolveProperty(propertyName, type);
113        if (property != null) {
114          return property.getValue();
115        }
116        return null;
117      }
118    
119      /**
120       * Resolve a context property or null if it cannot be resolved.
121       *
122       * @param desc the property descriptor
123       * @param <T> the property parameter type
124       * @return the property value
125       * @throws NullPointerException if the descriptor argument is null
126       */
127      public <T> Property<? extends T> resolveProperty(PropertyDescriptor<T> desc) throws NullPointerException {
128        if (desc == null) {
129          throw new NullPointerException();
130        }
131        return getProperty(desc.getName(), desc.getType());
132      }
133    
134      /**
135       * Resolve a context property or null if it cannot be resolved.
136       *
137       * @param propertyName the name of the property
138       * @param type the property type
139       * @param <T> the property parameter type
140       * @return the property value
141       * @throws NullPointerException if the descriptor argument is null
142       */
143      <T> Property<? extends T> resolveProperty(String propertyName, Class<T> type) throws NullPointerException {
144        if (propertyName == null) {
145          throw new NullPointerException("No null property name accepted");
146        }
147        if (type == null) {
148          throw new NullPointerException("No null property type accepted");
149        }
150        Property<?> property = properties.get(propertyName);
151        if (property != null) {
152          PropertyDescriptor<?> descriptor = property.getDescriptor();
153          if (type.isAssignableFrom(descriptor.getType())) {
154            return (Property<? extends T>)property;
155          }
156        }
157        return null;
158      }
159    
160      /**
161       * Set a context property to a new value. If the provided value is null, then the property is removed.
162       *
163       * @param desc the property descriptor
164       * @param value the property value
165       * @param <T> the property parameter type
166       * @throws NullPointerException if the descriptor argument is null
167       */
168      <T> void setProperty(PropertyDescriptor<T> desc, T value) throws NullPointerException {
169        if (desc == null) {
170          throw new NullPointerException("No null descriptor allowed");
171        }
172        if (value == null) {
173          log.log(Level.FINE, "Removing property " + desc.name);
174          properties.remove(desc.getName());
175        } else {
176          Property<T> property = new Property<T>(desc, value);
177          log.log(Level.FINE, "Setting property " + desc.name + " to value " + property.getValue());
178          properties.put(desc.getName(), property);
179        }
180      }
181    
182      /**
183       * Set a context property to a new value.
184       *
185       * @param desc the property descriptor
186       * @param value the property value
187       * @param <T> the property parameter type
188       * @throws NullPointerException if the descriptor argument or the value is null
189       * @throws IllegalArgumentException if the string value cannot be converted to the property type
190       */
191      <T> void parseProperty(PropertyDescriptor<T> desc, String value) throws NullPointerException, IllegalArgumentException {
192        if (desc == null) {
193          throw new NullPointerException("No null descriptor allowed");
194        }
195        if (value == null) {
196          throw new NullPointerException("No null value accepted");
197        } else {
198          Property<T> property = desc.toProperty(value);
199          log.log(Level.FINE, "Setting property " + desc.name + " to value " + property.getValue());
200          properties.put(desc.getName(), property);
201        }
202      }
203    }