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