001 /*
002 * Copyright (C) 2010 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.Collections;
023 import java.util.HashMap;
024 import java.util.Map;
025 import java.util.concurrent.TimeUnit;
026
027 /**
028 * A descriptor for a configuration property.
029 *
030 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
031 * @version $Revision$
032 */
033 public abstract class PropertyDescriptor<T> {
034
035 public static PropertyDescriptor<String> create(String name, String defaultValue, String description) {
036 return new PropertyDescriptor<String>(String.class, name, defaultValue, description) {
037 @Override
038 protected String doParse(String s) throws Exception {
039 return s;
040 }
041 };
042 }
043
044 public static PropertyDescriptor<Integer> create(String name, Integer defaultValue, String description) {
045 return new PropertyDescriptor<Integer>(Integer.class, name, defaultValue, description) {
046 @Override
047 protected Integer doParse(String s) throws Exception {
048 return Integer.parseInt(s);
049 }
050 };
051 }
052
053 /** . */
054 private static final Map<String, PropertyDescriptor<?>> INTERNAL_ALL = new HashMap<String, PropertyDescriptor<?>>();
055
056 /** . */
057 public static final Map<String, PropertyDescriptor<?>> ALL = Collections.unmodifiableMap(INTERNAL_ALL);
058
059 /** . */
060 public static final PropertyDescriptor<TimeUnit> VFS_REFRESH_UNIT = new PropertyDescriptor<TimeUnit>(TimeUnit.class, "vfs.refresh_unit", TimeUnit.SECONDS, "The refresh time unit") {
061 @Override
062 public TimeUnit doParse(String s) {
063 return TimeUnit.valueOf(s);
064 }
065 };
066
067 /** . */
068 public static final PropertyDescriptor<Integer> VFS_REFRESH_PERIOD = PropertyDescriptor.create("vfs.refresh_period", (Integer)null, "The refresh rate period");
069
070 /** . */
071 public final Class<T> type;
072
073 /** . */
074 public final String name;
075
076 /** . */
077 public final T defaultValue;
078
079 /** . */
080 public final String description;
081
082 /**
083 * Create a new property descriptor.
084 *
085 * @param type the property type
086 * @param name the property name
087 * @param defaultValue the default value
088 * @param description the description
089 * @throws NullPointerException if the type, name or description is null
090 */
091 protected PropertyDescriptor(Class<T> type, String name, T defaultValue, String description) throws NullPointerException {
092 if (type == null) {
093 throw new NullPointerException("No null type accepted");
094 }
095 if (name == null) {
096 throw new NullPointerException("No null name accepted");
097 }
098 if (description == null) {
099 throw new NullPointerException("No null description accepted");
100 }
101
102 this.type = type;
103 this.name = name;
104 this.defaultValue = defaultValue;
105 this.description = description;
106
107 //
108 INTERNAL_ALL.put(name, this);
109 }
110
111 public final String getName() {
112 return name;
113 }
114
115 public final String getDescription() {
116 return description;
117 }
118
119 public final Class<T> getType() {
120 return type;
121 }
122
123 public final T getDefaultValue() {
124 return defaultValue;
125 }
126
127 /**
128 * Parse a string representation of a value and returns the corresponding typed value.
129 *
130 * @param s the string to parse
131 * @return the corresponding value
132 * @throws NullPointerException if the argument is null
133 * @throws IllegalArgumentException if the string value cannot be parsed for some reason
134 */
135 public final T parse(String s) throws NullPointerException, IllegalArgumentException {
136 if (s == null) {
137 throw new NullPointerException("Cannot parse null property values");
138 }
139 try {
140 return doParse(s);
141 }
142 catch (Exception e) {
143 throw new IllegalArgumentException("Illegal property value " + s, e);
144 }
145 }
146
147 /**
148 * Parse a string representation of a value and returns the correspondig property value.
149 *
150 * @param s the string to parse
151 * @return the corresponding property
152 * @throws NullPointerException if the argument is null
153 * @throws IllegalArgumentException if the string value cannot be parsed for some reason
154 */
155 public final Property<T> toProperty(String s) throws NullPointerException, IllegalArgumentException {
156 T value = parse(s);
157 return new Property<T>(this, value);
158 }
159
160 /**
161 * Implements the real parsing, the string argument must nto be null. The returned value must not be null
162 * instead an exception must be thrown.
163 *
164 * @param s the string to parse
165 * @return the related value
166 * @throws Exception any exception that would prevent parsing to hapen
167 */
168 protected abstract T doParse(String s) throws Exception;
169
170 @Override
171 public final String toString() {
172 return "PropertyDescriptor[name=" + name + ",type=" + type.getName() + ",description=" + description + "]";
173 }
174 }