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/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 */
package org.apache.commons.collections;

import java.io.PrintStream;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.ResourceBundle;
import java.util.SortedMap;
import java.util.TreeMap;

import org.apache.commons.collections.map.FixedSizeMap;
import org.apache.commons.collections.map.FixedSizeSortedMap;
import org.apache.commons.collections.map.LazyMap;
import org.apache.commons.collections.map.LazySortedMap;
import org.apache.commons.collections.map.ListOrderedMap;
import org.apache.commons.collections.map.MultiValueMap;
import org.apache.commons.collections.map.PredicatedMap;
import org.apache.commons.collections.map.PredicatedSortedMap;
import org.apache.commons.collections.map.TransformedMap;
import org.apache.commons.collections.map.TransformedSortedMap;
import org.apache.commons.collections.map.TypedMap;
import org.apache.commons.collections.map.TypedSortedMap;
import org.apache.commons.collections.map.UnmodifiableMap;
import org.apache.commons.collections.map.UnmodifiableSortedMap;

/** 
 * Provides utility methods and decorators for
 * {@link Map} and {@link SortedMap} instances.
 * 

* It contains various type safe methods * as well as other useful features like deep copying. *

* It also provides the following decorators: * *

    *
  • {@link #fixedSizeMap(Map)} *
  • {@link #fixedSizeSortedMap(SortedMap)} *
  • {@link #lazyMap(Map,Factory)} *
  • {@link #lazyMap(Map,Transformer)} *
  • {@link #lazySortedMap(SortedMap,Factory)} *
  • {@link #lazySortedMap(SortedMap,Transformer)} *
  • {@link #predicatedMap(Map,Predicate,Predicate)} *
  • {@link #predicatedSortedMap(SortedMap,Predicate,Predicate)} *
  • {@link #transformedMap(Map, Transformer, Transformer)} *
  • {@link #transformedSortedMap(SortedMap, Transformer, Transformer)} *
  • {@link #typedMap(Map, Class, Class)} *
  • {@link #typedSortedMap(SortedMap, Class, Class)} *
  • {@link #multiValueMap( Map )} *
  • {@link #multiValueMap( Map, Class )} *
  • {@link #multiValueMap( Map, Factory )} *
* * @since Commons Collections 1.0 * @version $Revision: 1713178 $ $Date: 2015-11-07 21:59:09 +0100 (Sat, 07 Nov 2015) $ * * @author James Strachan * @author Nissim Karpenstein * @author Kasper Nielsen * @author Paul Jack * @author Stephen Colebourne * @author Matthew Hawthorne * @author Arun Mammen Thomas * @author Janek Bogucki * @author Max Rydahl Andersen * @author Ashwin S * @author James Carman * @author Neil O'Toole */ public class MapUtils { /** * An empty unmodifiable map. * This was not provided in JDK1.2. */ public static final Map EMPTY_MAP = UnmodifiableMap.decorate(new HashMap(1)); /** * An empty unmodifiable sorted map. * This is not provided in the JDK. */ public static final SortedMap EMPTY_SORTED_MAP = UnmodifiableSortedMap.decorate(new TreeMap()); /** * String used to indent the verbose and debug Map prints. */ private static final String INDENT_STRING = " "; /** * MapUtils should not normally be instantiated. */ public MapUtils() { } // Type safe getters //------------------------------------------------------------------------- /** * Gets from a Map in a null-safe manner. * * @param map the map to use * @param key the key to look up * @return the value in the Map, null if null map input */ public static Object getObject(final Map map, final Object key) { if (map != null) { return map.get(key); } return null; } /** * Gets a String from a Map in a null-safe manner. *

* The String is obtained via toString. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a String, null if null map input */ public static String getString(final Map map, final Object key) { if (map != null) { Object answer = map.get(key); if (answer != null) { return answer.toString(); } } return null; } /** * Gets a Boolean from a Map in a null-safe manner. *

* If the value is a Boolean it is returned directly. * If the value is a String and it equals 'true' ignoring case * then true is returned, otherwise false. * If the value is a Number an integer zero value returns * false and non-zero returns true. * Otherwise, null is returned. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Boolean, null if null map input */ public static Boolean getBoolean(final Map map, final Object key) { if (map != null) { Object answer = map.get(key); if (answer != null) { if (answer instanceof Boolean) { return (Boolean) answer; } else if (answer instanceof String) { return new Boolean((String) answer); } else if (answer instanceof Number) { Number n = (Number) answer; return (n.intValue() != 0) ? Boolean.TRUE : Boolean.FALSE; } } } return null; } /** * Gets a Number from a Map in a null-safe manner. *

* If the value is a Number it is returned directly. * If the value is a String it is converted using * {@link NumberFormat#parse(String)} on the system default formatter * returning null if the conversion fails. * Otherwise, null is returned. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Number, null if null map input */ public static Number getNumber(final Map map, final Object key) { if (map != null) { Object answer = map.get(key); if (answer != null) { if (answer instanceof Number) { return (Number) answer; } else if (answer instanceof String) { try { String text = (String) answer; return NumberFormat.getInstance().parse(text); } catch (ParseException e) { // failure means null is returned } } } } return null; } /** * Gets a Byte from a Map in a null-safe manner. *

* The Byte is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Byte, null if null map input */ public static Byte getByte(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Byte) { return (Byte) answer; } return new Byte(answer.byteValue()); } /** * Gets a Short from a Map in a null-safe manner. *

* The Short is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Short, null if null map input */ public static Short getShort(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Short) { return (Short) answer; } return new Short(answer.shortValue()); } /** * Gets a Integer from a Map in a null-safe manner. *

* The Integer is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Integer, null if null map input */ public static Integer getInteger(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Integer) { return (Integer) answer; } return new Integer(answer.intValue()); } /** * Gets a Long from a Map in a null-safe manner. *

* The Long is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Long, null if null map input */ public static Long getLong(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Long) { return (Long) answer; } return new Long(answer.longValue()); } /** * Gets a Float from a Map in a null-safe manner. *

* The Float is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Float, null if null map input */ public static Float getFloat(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Float) { return (Float) answer; } return new Float(answer.floatValue()); } /** * Gets a Double from a Map in a null-safe manner. *

* The Double is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Double, null if null map input */ public static Double getDouble(final Map map, final Object key) { Number answer = getNumber(map, key); if (answer == null) { return null; } else if (answer instanceof Double) { return (Double) answer; } return new Double(answer.doubleValue()); } /** * Gets a Map from a Map in a null-safe manner. *

* If the value returned from the specified map is not a Map then * null is returned. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Map, null if null map input */ public static Map getMap(final Map map, final Object key) { if (map != null) { Object answer = map.get(key); if (answer != null && answer instanceof Map) { return (Map) answer; } } return null; } // Type safe getters with default values //------------------------------------------------------------------------- /** * Looks up the given key in the given map, converting null into the * given default value. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null * @return the value in the map, or defaultValue if the original value * is null or the map is null */ public static Object getObject( Map map, Object key, Object defaultValue ) { if ( map != null ) { Object answer = map.get( key ); if ( answer != null ) { return answer; } } return defaultValue; } /** * Looks up the given key in the given map, converting the result into * a string, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a string, or defaultValue if the * original value is null, the map is null or the string conversion * fails */ public static String getString( Map map, Object key, String defaultValue ) { String answer = getString( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a boolean, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a boolean, or defaultValue if the * original value is null, the map is null or the boolean conversion * fails */ public static Boolean getBoolean( Map map, Object key, Boolean defaultValue ) { Boolean answer = getBoolean( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a number, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Number getNumber( Map map, Object key, Number defaultValue ) { Number answer = getNumber( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a byte, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Byte getByte( Map map, Object key, Byte defaultValue ) { Byte answer = getByte( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a short, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Short getShort( Map map, Object key, Short defaultValue ) { Short answer = getShort( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * an integer, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Integer getInteger( Map map, Object key, Integer defaultValue ) { Integer answer = getInteger( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a long, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Long getLong( Map map, Object key, Long defaultValue ) { Long answer = getLong( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a float, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Float getFloat( Map map, Object key, Float defaultValue ) { Float answer = getFloat( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a double, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the number conversion * fails */ public static Double getDouble( Map map, Object key, Double defaultValue ) { Double answer = getDouble( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } /** * Looks up the given key in the given map, converting the result into * a map, using the default value if the the conversion fails. * * @param map the map whose value to look up * @param key the key of the value to look up in that map * @param defaultValue what to return if the value is null or if the * conversion fails * @return the value in the map as a number, or defaultValue if the * original value is null, the map is null or the map conversion * fails */ public static Map getMap( Map map, Object key, Map defaultValue ) { Map answer = getMap( map, key ); if ( answer == null ) { answer = defaultValue; } return answer; } // Type safe primitive getters //------------------------------------------------------------------------- /** * Gets a boolean from a Map in a null-safe manner. *

* If the value is a Boolean its value is returned. * If the value is a String and it equals 'true' ignoring case * then true is returned, otherwise false. * If the value is a Number an integer zero value returns * false and non-zero returns true. * Otherwise, false is returned. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a Boolean, false if null map input */ public static boolean getBooleanValue(final Map map, final Object key) { Boolean booleanObject = getBoolean(map, key); if (booleanObject == null) { return false; } return booleanObject.booleanValue(); } /** * Gets a byte from a Map in a null-safe manner. *

* The byte is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a byte, 0 if null map input */ public static byte getByteValue(final Map map, final Object key) { Byte byteObject = getByte(map, key); if (byteObject == null) { return 0; } return byteObject.byteValue(); } /** * Gets a short from a Map in a null-safe manner. *

* The short is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a short, 0 if null map input */ public static short getShortValue(final Map map, final Object key) { Short shortObject = getShort(map, key); if (shortObject == null) { return 0; } return shortObject.shortValue(); } /** * Gets an int from a Map in a null-safe manner. *

* The int is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as an int, 0 if null map input */ public static int getIntValue(final Map map, final Object key) { Integer integerObject = getInteger(map, key); if (integerObject == null) { return 0; } return integerObject.intValue(); } /** * Gets a long from a Map in a null-safe manner. *

* The long is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a long, 0L if null map input */ public static long getLongValue(final Map map, final Object key) { Long longObject = getLong(map, key); if (longObject == null) { return 0L; } return longObject.longValue(); } /** * Gets a float from a Map in a null-safe manner. *

* The float is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a float, 0.0F if null map input */ public static float getFloatValue(final Map map, final Object key) { Float floatObject = getFloat(map, key); if (floatObject == null) { return 0f; } return floatObject.floatValue(); } /** * Gets a double from a Map in a null-safe manner. *

* The double is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @return the value in the Map as a double, 0.0 if null map input */ public static double getDoubleValue(final Map map, final Object key) { Double doubleObject = getDouble(map, key); if (doubleObject == null) { return 0d; } return doubleObject.doubleValue(); } // Type safe primitive getters with default values //------------------------------------------------------------------------- /** * Gets a boolean from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* If the value is a Boolean its value is returned. * If the value is a String and it equals 'true' ignoring case * then true is returned, otherwise false. * If the value is a Number an integer zero value returns * false and non-zero returns true. * Otherwise, defaultValue is returned. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a Boolean, defaultValue if null map input */ public static boolean getBooleanValue(final Map map, final Object key, boolean defaultValue) { Boolean booleanObject = getBoolean(map, key); if (booleanObject == null) { return defaultValue; } return booleanObject.booleanValue(); } /** * Gets a byte from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The byte is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a byte, defaultValue if null map input */ public static byte getByteValue(final Map map, final Object key, byte defaultValue) { Byte byteObject = getByte(map, key); if (byteObject == null) { return defaultValue; } return byteObject.byteValue(); } /** * Gets a short from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The short is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a short, defaultValue if null map input */ public static short getShortValue(final Map map, final Object key, short defaultValue) { Short shortObject = getShort(map, key); if (shortObject == null) { return defaultValue; } return shortObject.shortValue(); } /** * Gets an int from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The int is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as an int, defaultValue if null map input */ public static int getIntValue(final Map map, final Object key, int defaultValue) { Integer integerObject = getInteger(map, key); if (integerObject == null) { return defaultValue; } return integerObject.intValue(); } /** * Gets a long from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The long is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a long, defaultValue if null map input */ public static long getLongValue(final Map map, final Object key, long defaultValue) { Long longObject = getLong(map, key); if (longObject == null) { return defaultValue; } return longObject.longValue(); } /** * Gets a float from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The float is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a float, defaultValue if null map input */ public static float getFloatValue(final Map map, final Object key, float defaultValue) { Float floatObject = getFloat(map, key); if (floatObject == null) { return defaultValue; } return floatObject.floatValue(); } /** * Gets a double from a Map in a null-safe manner, * using the default value if the the conversion fails. *

* The double is obtained from the results of {@link #getNumber(Map,Object)}. * * @param map the map to use * @param key the key to look up * @param defaultValue return if the value is null or if the * conversion fails * @return the value in the Map as a double, defaultValue if null map input */ public static double getDoubleValue(final Map map, final Object key, double defaultValue) { Double doubleObject = getDouble(map, key); if (doubleObject == null) { return defaultValue; } return doubleObject.doubleValue(); } // Conversion methods //------------------------------------------------------------------------- /** * Gets a new Properties object initialised with the values from a Map. * A null input will return an empty properties object. * * @param map the map to convert to a Properties object, may not be null * @return the properties object */ public static Properties toProperties(final Map map) { Properties answer = new Properties(); if (map != null) { for (Iterator iter = map.entrySet().iterator(); iter.hasNext();) { Map.Entry entry = (Map.Entry) iter.next(); Object key = entry.getKey(); Object value = entry.getValue(); answer.put(key, value); } } return answer; } /** * Creates a new HashMap using data copied from a ResourceBundle. * * @param resourceBundle the resource bundle to convert, may not be null * @return the hashmap containing the data * @throws NullPointerException if the bundle is null */ public static Map toMap(final ResourceBundle resourceBundle) { Enumeration enumeration = resourceBundle.getKeys(); Map map = new HashMap(); while (enumeration.hasMoreElements()) { String key = (String) enumeration.nextElement(); Object value = resourceBundle.getObject(key); map.put(key, value); } return map; } // Printing methods //------------------------------------------------------------------------- /** * Prints the given map with nice line breaks. *

* This method prints a nicely formatted String describing the Map. * Each map entry will be printed with key and value. * When the value is a Map, recursive behaviour occurs. *

* This method is NOT thread-safe in any special way. You must manually * synchronize on either this class or the stream as required. * * @param out the stream to print to, must not be null * @param label The label to be used, may be null. * If null, the label is not output. * It typically represents the name of the property in a bean or similar. * @param map The map to print, may be null. * If null, the text 'null' is output. * @throws NullPointerException if the stream is null */ public static void verbosePrint( final PrintStream out, final Object label, final Map map) { verbosePrintInternal(out, label, map, new ArrayStack(), false); } /** * Prints the given map with nice line breaks. *

* This method prints a nicely formatted String describing the Map. * Each map entry will be printed with key, value and value classname. * When the value is a Map, recursive behaviour occurs. *

* This method is NOT thread-safe in any special way. You must manually * synchronize on either this class or the stream as required. * * @param out the stream to print to, must not be null * @param label The label to be used, may be null. * If null, the label is not output. * It typically represents the name of the property in a bean or similar. * @param map The map to print, may be null. * If null, the text 'null' is output. * @throws NullPointerException if the stream is null */ public static void debugPrint( final PrintStream out, final Object label, final Map map) { verbosePrintInternal(out, label, map, new ArrayStack(), true); } // Implementation methods //------------------------------------------------------------------------- /** * Logs the given exception to System.out. *

* This method exists as Jakarta Collections does not depend on logging. * * @param ex the exception to log */ protected static void logInfo(final Exception ex) { System.out.println("INFO: Exception: " + ex); } /** * Implementation providing functionality for {@link #debugPrint} and for * {@link #verbosePrint}. This prints the given map with nice line breaks. * If the debug flag is true, it additionally prints the type of the object * value. If the contents of a map include the map itself, then the text * (this Map) is printed out. If the contents include a * parent container of the map, the the text (ancestor[i] Map) is * printed, where i actually indicates the number of levels which must be * traversed in the sequential list of ancestors (e.g. father, grandfather, * great-grandfather, etc). * * @param out the stream to print to * @param label the label to be used, may be null. * If null, the label is not output. * It typically represents the name of the property in a bean or similar. * @param map the map to print, may be null. * If null, the text 'null' is output * @param lineage a stack consisting of any maps in which the previous * argument is contained. This is checked to avoid infinite recursion when * printing the output * @param debug flag indicating whether type names should be output. * @throws NullPointerException if the stream is null */ private static void verbosePrintInternal( final PrintStream out, final Object label, final Map map, final ArrayStack lineage, final boolean debug) { printIndent(out, lineage.size()); if (map == null) { if (label != null) { out.print(label); out.print(" = "); } out.println("null"); return; } if (label != null) { out.print(label); out.println(" = "); } printIndent(out, lineage.size()); out.println("{"); lineage.push(map); for (Iterator it = map.entrySet().iterator(); it.hasNext();) { Map.Entry entry = (Map.Entry) it.next(); Object childKey = entry.getKey(); Object childValue = entry.getValue(); if (childValue instanceof Map && !lineage.contains(childValue)) { verbosePrintInternal( out, (childKey == null ? "null" : childKey), (Map) childValue, lineage, debug); } else { printIndent(out, lineage.size()); out.print(childKey); out.print(" = "); final int lineageIndex = lineage.indexOf(childValue); if (lineageIndex == -1) { out.print(childValue); } else if (lineage.size() - 1 == lineageIndex) { out.print("(this Map)"); } else { out.print( "(ancestor[" + (lineage.size() - 1 - lineageIndex - 1) + "] Map)"); } if (debug && childValue != null) { out.print(' '); out.println(childValue.getClass().getName()); } else { out.println(); } } } lineage.pop(); printIndent(out, lineage.size()); out.println(debug ? "} " + map.getClass().getName() : "}"); } /** * Writes indentation to the given stream. * * @param out the stream to indent */ private static void printIndent(final PrintStream out, final int indent) { for (int i = 0; i < indent; i++) { out.print(INDENT_STRING); } } // Misc //----------------------------------------------------------------------- /** * Inverts the supplied map returning a new HashMap such that the keys of * the input are swapped with the values. *

* This operation assumes that the inverse mapping is well defined. * If the input map had multiple entries with the same value mapped to * different keys, the returned map will map one of those keys to the * value, but the exact key which will be mapped is undefined. * * @param map the map to invert, may not be null * @return a new HashMap containing the inverted data * @throws NullPointerException if the map is null */ public static Map invertMap(Map map) { Map out = new HashMap(map.size()); for (Iterator it = map.entrySet().iterator(); it.hasNext();) { Map.Entry entry = (Map.Entry) it.next(); out.put(entry.getValue(), entry.getKey()); } return out; } //----------------------------------------------------------------------- /** * Protects against adding null values to a map. *

* This method checks the value being added to the map, and if it is null * it is replaced by an empty string. *

* This could be useful if the map does not accept null values, or for * receiving data from a source that may provide null or empty string * which should be held in the same way in the map. *

* Keys are not validated. * * @param map the map to add to, may not be null * @param key the key * @param value the value, null converted to "" * @throws NullPointerException if the map is null */ public static void safeAddToMap(Map map, Object key, Object value) throws NullPointerException { if (value == null) { map.put(key, ""); } else { map.put(key, value); } } //----------------------------------------------------------------------- /** * Puts all the keys and values from the specified array into the map. *

* This method is an alternative to the {@link java.util.Map#putAll(java.util.Map)} * method and constructors. It allows you to build a map from an object array * of various possible styles. *

* If the first entry in the object array implements {@link java.util.Map.Entry} * or {@link KeyValue} then the key and value are added from that object. * If the first entry in the object array is an object array itself, then * it is assumed that index 0 in the sub-array is the key and index 1 is the value. * Otherwise, the array is treated as keys and values in alternate indices. *

* For example, to create a color map: *

     * Map colorMap = MapUtils.putAll(new HashMap(), new String[][] {
     *     {"RED", "#FF0000"},
     *     {"GREEN", "#00FF00"},
     *     {"BLUE", "#0000FF"}
     * });
     * 
* or: *
     * Map colorMap = MapUtils.putAll(new HashMap(), new String[] {
     *     "RED", "#FF0000",
     *     "GREEN", "#00FF00",
     *     "BLUE", "#0000FF"
     * });
     * 
* or: *
     * Map colorMap = MapUtils.putAll(new HashMap(), new Map.Entry[] {
     *     new DefaultMapEntry("RED", "#FF0000"),
     *     new DefaultMapEntry("GREEN", "#00FF00"),
     *     new DefaultMapEntry("BLUE", "#0000FF")
     * });
     * 
* * @param map the map to populate, must not be null * @param array an array to populate from, null ignored * @return the input map * @throws NullPointerException if map is null * @throws IllegalArgumentException if sub-array or entry matching used and an * entry is invalid * @throws ClassCastException if the array contents is mixed * @since Commons Collections 3.2 */ public static Map putAll(Map map, Object[] array) { map.size(); // force NPE if (array == null || array.length == 0) { return map; } Object obj = array[0]; if (obj instanceof Map.Entry) { for (int i = 0; i < array.length; i++) { Map.Entry entry = (Map.Entry) array[i]; map.put(entry.getKey(), entry.getValue()); } } else if (obj instanceof KeyValue) { for (int i = 0; i < array.length; i++) { KeyValue keyval = (KeyValue) array[i]; map.put(keyval.getKey(), keyval.getValue()); } } else if (obj instanceof Object[]) { for (int i = 0; i < array.length; i++) { Object[] sub = (Object[]) array[i]; if (sub == null || sub.length < 2) { throw new IllegalArgumentException("Invalid array element: " + i); } map.put(sub[0], sub[1]); } } else { for (int i = 0; i < array.length - 1;) { map.put(array[i++], array[i++]); } } return map; } //----------------------------------------------------------------------- /** * Null-safe check if the specified map is empty. *

* Null returns true. * * @param map the map to check, may be null * @return true if empty or null * @since Commons Collections 3.2 */ public static boolean isEmpty(Map map) { return (map == null || map.isEmpty()); } /** * Null-safe check if the specified map is not empty. *

* Null returns false. * * @param map the map to check, may be null * @return true if non-null and non-empty * @since Commons Collections 3.2 */ public static boolean isNotEmpty(Map map) { return !MapUtils.isEmpty(map); } // Map decorators //----------------------------------------------------------------------- /** * Returns a synchronized map backed by the given map. *

* You must manually synchronize on the returned buffer's iterator to * avoid non-deterministic behavior: * *

     * Map m = MapUtils.synchronizedMap(myMap);
     * Set s = m.keySet();  // outside synchronized block
     * synchronized (m) {  // synchronized on MAP!
     *     Iterator i = s.iterator();
     *     while (i.hasNext()) {
     *         process (i.next());
     *     }
     * }
     * 
* * This method uses the implementation in {@link java.util.Collections Collections}. * * @param map the map to synchronize, must not be null * @return a synchronized map backed by the given map * @throws IllegalArgumentException if the map is null */ public static Map synchronizedMap(Map map) { return Collections.synchronizedMap(map); } /** * Returns an unmodifiable map backed by the given map. *

* This method uses the implementation in the decorators subpackage. * * @param map the map to make unmodifiable, must not be null * @return an unmodifiable map backed by the given map * @throws IllegalArgumentException if the map is null */ public static Map unmodifiableMap(Map map) { return UnmodifiableMap.decorate(map); } /** * Returns a predicated (validating) map backed by the given map. *

* Only objects that pass the tests in the given predicates can be added to the map. * Trying to add an invalid object results in an IllegalArgumentException. * Keys must pass the key predicate, values must pass the value predicate. * It is important not to use the original map after invoking this method, * as it is a backdoor for adding invalid objects. * * @param map the map to predicate, must not be null * @param keyPred the predicate for keys, null means no check * @param valuePred the predicate for values, null means no check * @return a predicated map backed by the given map * @throws IllegalArgumentException if the Map is null */ public static Map predicatedMap(Map map, Predicate keyPred, Predicate valuePred) { return PredicatedMap.decorate(map, keyPred, valuePred); } /** * Returns a typed map backed by the given map. *

* Only keys and values of the specified types can be added to the map. * * @param map the map to limit to a specific type, must not be null * @param keyType the type of keys which may be added to the map, must not be null * @param valueType the type of values which may be added to the map, must not be null * @return a typed map backed by the specified map * @throws IllegalArgumentException if the Map or Class is null */ public static Map typedMap(Map map, Class keyType, Class valueType) { return TypedMap.decorate(map, keyType, valueType); } /** * Returns a transformed map backed by the given map. *

* This method returns a new map (decorating the specified map) that * will transform any new entries added to it. * Existing entries in the specified map will not be transformed. * If you want that behaviour, see {@link TransformedMap#decorateTransform}. *

* Each object is passed through the transformers as it is added to the * Map. It is important not to use the original map after invoking this * method, as it is a backdoor for adding untransformed objects. *

* If there are any elements already in the map being decorated, they * are NOT transformed. * * @param map the map to transform, must not be null, typically empty * @param keyTransformer the transformer for the map keys, null means no transformation * @param valueTransformer the transformer for the map values, null means no transformation * @return a transformed map backed by the given map * @throws IllegalArgumentException if the Map is null */ public static Map transformedMap(Map map, Transformer keyTransformer, Transformer valueTransformer) { return TransformedMap.decorate(map, keyTransformer, valueTransformer); } /** * Returns a fixed-sized map backed by the given map. * Elements may not be added or removed from the returned map, but * existing elements can be changed (for instance, via the * {@link Map#put(Object,Object)} method). * * @param map the map whose size to fix, must not be null * @return a fixed-size map backed by that map * @throws IllegalArgumentException if the Map is null */ public static Map fixedSizeMap(Map map) { return FixedSizeMap.decorate(map); } /** * Returns a "lazy" map whose values will be created on demand. *

* When the key passed to the returned map's {@link Map#get(Object)} * method is not present in the map, then the factory will be used * to create a new object and that object will become the value * associated with that key. *

* For instance: *

     * Factory factory = new Factory() {
     *     public Object create() {
     *         return new Date();
     *     }
     * }
     * Map lazyMap = MapUtils.lazyMap(new HashMap(), factory);
     * Object obj = lazyMap.get("test");
     * 
* * After the above code is executed, obj will contain * a new Date instance. Furthermore, that Date * instance is the value for the "test" key in the map. * * @param map the map to make lazy, must not be null * @param factory the factory for creating new objects, must not be null * @return a lazy map backed by the given map * @throws IllegalArgumentException if the Map or Factory is null */ public static Map lazyMap(Map map, Factory factory) { return LazyMap.decorate(map, factory); } /** * Returns a "lazy" map whose values will be created on demand. *

* When the key passed to the returned map's {@link Map#get(Object)} * method is not present in the map, then the factory will be used * to create a new object and that object will become the value * associated with that key. The factory is a {@link Transformer} * that will be passed the key which it must transform into the value. *

* For instance: *

     * Transformer factory = new Transformer() {
     *     public Object transform(Object mapKey) {
     *         return new File(mapKey);
     *     }
     * }
     * Map lazyMap = MapUtils.lazyMap(new HashMap(), factory);
     * Object obj = lazyMap.get("C:/dev");
     * 
* * After the above code is executed, obj will contain * a new File instance for the C drive dev directory. * Furthermore, that File instance is the value for the * "C:/dev" key in the map. *

* If a lazy map is wrapped by a synchronized map, the result is a simple * synchronized cache. When an object is not is the cache, the cache itself * calls back to the factory Transformer to populate itself, all within the * same synchronized block. * * @param map the map to make lazy, must not be null * @param transformerFactory the factory for creating new objects, must not be null * @return a lazy map backed by the given map * @throws IllegalArgumentException if the Map or Transformer is null */ public static Map lazyMap(Map map, Transformer transformerFactory) { return LazyMap.decorate(map, transformerFactory); } /** * Returns a map that maintains the order of keys that are added * backed by the given map. *

* If a key is added twice, the order is determined by the first add. * The order is observed through the keySet, values and entrySet. * * @param map the map to order, must not be null * @return an ordered map backed by the given map * @throws IllegalArgumentException if the Map is null */ public static Map orderedMap(Map map) { return ListOrderedMap.decorate(map); } /** * Creates a mult-value map backed by the given map which returns * collections of type ArrayList. * * @param map the map to decorate * @return a multi-value map backed by the given map which returns ArrayLists of values. * @see MultiValueMap * @since Commons Collections 3.2 */ public static Map multiValueMap(Map map) { return MultiValueMap.decorate(map); } /** * Creates a multi-value map backed by the given map which returns * collections of the specified type. * * @param map the map to decorate * @param collectionClass the type of collections to return from the map (must contain public no-arg constructor * and extend Collection). * @return a multi-value map backed by the given map which returns collections of the specified type * @see MultiValueMap * @since Commons Collections 3.2 */ public static Map multiValueMap(Map map, Class collectionClass) { return MultiValueMap.decorate(map, collectionClass); } /** * Creates a multi-value map backed by the given map which returns * collections created by the specified collection factory. * * @param map the map to decorate * @param collectionFactory a factor which creates collection objects * @return a multi-value map backed by the given map which returns collections * created by the specified collection factory * @see MultiValueMap * @since Commons Collections 3.2 */ public static Map multiValueMap(Map map, Factory collectionFactory) { return MultiValueMap.decorate(map, collectionFactory); } // SortedMap decorators //----------------------------------------------------------------------- /** * Returns a synchronized sorted map backed by the given sorted map. *

* You must manually synchronize on the returned buffer's iterator to * avoid non-deterministic behavior: * *

     * Map m = MapUtils.synchronizedSortedMap(myMap);
     * Set s = m.keySet();  // outside synchronized block
     * synchronized (m) {  // synchronized on MAP!
     *     Iterator i = s.iterator();
     *     while (i.hasNext()) {
     *         process (i.next());
     *     }
     * }
     * 
* * This method uses the implementation in {@link java.util.Collections Collections}. * * @param map the map to synchronize, must not be null * @return a synchronized map backed by the given map * @throws IllegalArgumentException if the map is null */ public static Map synchronizedSortedMap(SortedMap map) { return Collections.synchronizedSortedMap(map); } /** * Returns an unmodifiable sorted map backed by the given sorted map. *

* This method uses the implementation in the decorators subpackage. * * @param map the sorted map to make unmodifiable, must not be null * @return an unmodifiable map backed by the given map * @throws IllegalArgumentException if the map is null */ public static Map unmodifiableSortedMap(SortedMap map) { return UnmodifiableSortedMap.decorate(map); } /** * Returns a predicated (validating) sorted map backed by the given map. *

* Only objects that pass the tests in the given predicates can be added to the map. * Trying to add an invalid object results in an IllegalArgumentException. * Keys must pass the key predicate, values must pass the value predicate. * It is important not to use the original map after invoking this method, * as it is a backdoor for adding invalid objects. * * @param map the map to predicate, must not be null * @param keyPred the predicate for keys, null means no check * @param valuePred the predicate for values, null means no check * @return a predicated map backed by the given map * @throws IllegalArgumentException if the SortedMap is null */ public static SortedMap predicatedSortedMap(SortedMap map, Predicate keyPred, Predicate valuePred) { return PredicatedSortedMap.decorate(map, keyPred, valuePred); } /** * Returns a typed sorted map backed by the given map. *

* Only keys and values of the specified types can be added to the map. * * @param map the map to limit to a specific type, must not be null * @param keyType the type of keys which may be added to the map, must not be null * @param valueType the type of values which may be added to the map, must not be null * @return a typed map backed by the specified map */ public static SortedMap typedSortedMap(SortedMap map, Class keyType, Class valueType) { return TypedSortedMap.decorate(map, keyType, valueType); } /** * Returns a transformed sorted map backed by the given map. *

* This method returns a new sorted map (decorating the specified map) that * will transform any new entries added to it. * Existing entries in the specified map will not be transformed. * If you want that behaviour, see {@link TransformedSortedMap#decorateTransform}. *

* Each object is passed through the transformers as it is added to the * Map. It is important not to use the original map after invoking this * method, as it is a backdoor for adding untransformed objects. *

* If there are any elements already in the map being decorated, they * are NOT transformed. * * @param map the map to transform, must not be null, typically empty * @param keyTransformer the transformer for the map keys, null means no transformation * @param valueTransformer the transformer for the map values, null means no transformation * @return a transformed map backed by the given map * @throws IllegalArgumentException if the SortedMap is null */ public static SortedMap transformedSortedMap(SortedMap map, Transformer keyTransformer, Transformer valueTransformer) { return TransformedSortedMap.decorate(map, keyTransformer, valueTransformer); } /** * Returns a fixed-sized sorted map backed by the given sorted map. * Elements may not be added or removed from the returned map, but * existing elements can be changed (for instance, via the * {@link Map#put(Object,Object)} method). * * @param map the map whose size to fix, must not be null * @return a fixed-size map backed by that map * @throws IllegalArgumentException if the SortedMap is null */ public static SortedMap fixedSizeSortedMap(SortedMap map) { return FixedSizeSortedMap.decorate(map); } /** * Returns a "lazy" sorted map whose values will be created on demand. *

* When the key passed to the returned map's {@link Map#get(Object)} * method is not present in the map, then the factory will be used * to create a new object and that object will become the value * associated with that key. *

* For instance: * *

     * Factory factory = new Factory() {
     *     public Object create() {
     *         return new Date();
     *     }
     * }
     * SortedMap lazy = MapUtils.lazySortedMap(new TreeMap(), factory);
     * Object obj = lazy.get("test");
     * 
* * After the above code is executed, obj will contain * a new Date instance. Furthermore, that Date * instance is the value for the "test" key. * * @param map the map to make lazy, must not be null * @param factory the factory for creating new objects, must not be null * @return a lazy map backed by the given map * @throws IllegalArgumentException if the SortedMap or Factory is null */ public static SortedMap lazySortedMap(SortedMap map, Factory factory) { return LazySortedMap.decorate(map, factory); } /** * Returns a "lazy" sorted map whose values will be created on demand. *

* When the key passed to the returned map's {@link Map#get(Object)} * method is not present in the map, then the factory will be used * to create a new object and that object will become the value * associated with that key. The factory is a {@link Transformer} * that will be passed the key which it must transform into the value. *

* For instance: *

     * Transformer factory = new Transformer() {
     *     public Object transform(Object mapKey) {
     *         return new File(mapKey);
     *     }
     * }
     * SortedMap lazy = MapUtils.lazySortedMap(new TreeMap(), factory);
     * Object obj = lazy.get("C:/dev");
     * 
* * After the above code is executed, obj will contain * a new File instance for the C drive dev directory. * Furthermore, that File instance is the value for the * "C:/dev" key in the map. *

* If a lazy map is wrapped by a synchronized map, the result is a simple * synchronized cache. When an object is not is the cache, the cache itself * calls back to the factory Transformer to populate itself, all within the * same synchronized block. * * @param map the map to make lazy, must not be null * @param transformerFactory the factory for creating new objects, must not be null * @return a lazy map backed by the given map * @throws IllegalArgumentException if the Map or Transformer is null */ public static SortedMap lazySortedMap(SortedMap map, Transformer transformerFactory) { return LazySortedMap.decorate(map, transformerFactory); } }





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