Java tutorial
/* * Copyright 2006-2007 The Scriptella Project Team. * * 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. */ import java.io.IOException; import java.io.InputStream; import java.util.Collection; import java.util.LinkedHashMap; import java.util.Map; import java.util.Properties; import java.util.Set; /** * Represents a persistent set of properties. * <p>This class is a replacement for {@link Properties} class. * <p>Please note that {@link #put(String,Object)} has additional semantics. * * @author Fyodor Kupolov * @version 1.0 */ public class PropertiesMap implements Map<String, Object> { private Map<String, Object> props; public PropertiesMap() { props = new LinkedHashMap<String, Object>(); } public PropertiesMap(int initialCapacity) { props = new LinkedHashMap<String, Object>(initialCapacity); } public PropertiesMap(Map<String, ?> props) { this(props.size()); putAll(props); } /** * Creates a properties map from the stream. * * @param is stream to {@link #load(java.io.InputStream) load} properties from. * @throws IOException if I/O error occurs * @see #load(java.io.InputStream) */ public PropertiesMap(InputStream is) throws IOException { this(); load(is); } public int size() { return props.size(); } public boolean isEmpty() { return props.isEmpty(); } public boolean containsKey(Object key) { return props.containsKey(key); } public boolean containsValue(Object value) { return props.containsValue(value); } public Object get(Object key) { return props.get(key); } /** * Put the property to underlying map. * <p>The properties are immutable, i.e. if the property is already present in the map, the new value is ignored. * * @param key property name * @param value property value * @return value associated with specified key, * or null if there was no mapping for key. */ public Object put(String key, Object value) { Object old = props.get(key); if (old == null) { props.put(key, value); } return old; } public Object remove(Object key) { return props.remove(key); } public void putAll(Map<? extends String, ? extends Object> t) { for (Entry<? extends String, ? extends Object> entry : t.entrySet()) { put(entry.getKey(), entry.getValue()); } } public void clear() { props.clear(); } public Set<String> keySet() { return props.keySet(); } public Collection<Object> values() { return props.values(); } public Set<Entry<String, Object>> entrySet() { return props.entrySet(); } public boolean equals(Object o) { return props.equals(o); } public int hashCode() { return props.hashCode(); } /** * Loads properties using {@link Properties#load(java.io.InputStream)}. * <p>Properties order is preserved * * @param is input stream with properties. * @throws IOException if I/O error occurs. */ public void load(InputStream is) throws IOException { new Properties() { //Overrides Properties to preserve insertion order public Object put(final Object k, final Object v) { return PropertiesMap.this.put((String) k, v); } }.load(is); } public String toString() { return String.valueOf(props); } }