Java tutorial
/* * Copyright (c) 2000, 2008, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.management.openmbean; // java import // import java.io.Serializable; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.LinkedHashMap; import java.util.Map; import java.util.Set; import java.util.SortedMap; import java.util.TreeMap; // jmx import import java.util.TreeSet; // /** * The {@code CompositeDataSupport} class is the <i>open data</i> class which * implements the {@code CompositeData} interface. * * * @since 1.5 */ public class CompositeDataSupport implements CompositeData, Serializable { /* Serial version */ static final long serialVersionUID = 8003518976613702244L; /** * @serial Internal representation of the mapping of item names to their * respective values. * A {@link SortedMap} is used for faster retrieval of elements. */ private final SortedMap<String, Object> contents; /** * @serial The <i>composite type </i> of this <i>composite data</i> instance. */ private final CompositeType compositeType; /** * <p>Constructs a {@code CompositeDataSupport} instance with the specified * {@code compositeType}, whose item values * are specified by {@code itemValues[]}, in the same order as in * {@code itemNames[]}. * As a {@code CompositeType} does not specify any order on its items, * the {@code itemNames[]} parameter is used * to specify the order in which the values are given in {@code itemValues[]}. * The items contained in this {@code CompositeDataSupport} instance are * internally stored in a {@code TreeMap}, * thus sorted in ascending lexicographic order of their names, for faster * retrieval of individual item values.</p> * * <p>The constructor checks that all the constraints listed below for each * parameter are satisfied, * and throws the appropriate exception if they are not.</p> * * @param compositeType the <i>composite type </i> of this <i>composite * data</i> instance; must not be null. * * @param itemNames {@code itemNames} must list, in any order, all the * item names defined in {@code compositeType}; the order in which the * names are listed, is used to match values in {@code itemValues[]}; must * not be null or empty. * * @param itemValues the values of the items, listed in the same order as * their respective names in {@code itemNames}; each item value can be * null, but if it is non-null it must be a valid value for the open type * defined in {@code compositeType} for the corresponding item; must be of * the same size as {@code itemNames}; must not be null or empty. * * @throws IllegalArgumentException {@code compositeType} is null, or * {@code itemNames[]} or {@code itemValues[]} is null or empty, or one * of the elements in {@code itemNames[]} is a null or empty string, or * {@code itemNames[]} and {@code itemValues[]} are not of the same size. * * @throws OpenDataException {@code itemNames[]} or * {@code itemValues[]}'s size differs from the number of items defined in * {@code compositeType}, or one of the elements in {@code itemNames[]} * does not exist as an item name defined in {@code compositeType}, or one * of the elements in {@code itemValues[]} is not a valid value for the * corresponding item as defined in {@code compositeType}. */ public CompositeDataSupport(CompositeType compositeType, String[] itemNames, Object[] itemValues) throws OpenDataException { this(makeMap(itemNames, itemValues), compositeType); } private static SortedMap<String, Object> makeMap(String[] itemNames, Object[] itemValues) throws OpenDataException { if (itemNames == null || itemValues == null) throw new IllegalArgumentException("Null itemNames or itemValues"); if (itemNames.length == 0 || itemValues.length == 0) throw new IllegalArgumentException("Empty itemNames or itemValues"); if (itemNames.length != itemValues.length) { throw new IllegalArgumentException("Different lengths: itemNames[" + itemNames.length + "], itemValues[" + itemValues.length + "]"); } SortedMap<String, Object> map = new TreeMap<String, Object>(); for (int i = 0; i < itemNames.length; i++) { String name = itemNames[i]; if (name == null || name.equals("")) throw new IllegalArgumentException("Null or empty item name"); if (map.containsKey(name)) throw new OpenDataException("Duplicate item name " + name); map.put(itemNames[i], itemValues[i]); } return map; } /** * <p> * Constructs a {@code CompositeDataSupport} instance with the specified {@code compositeType}, * whose item names and corresponding values * are given by the mappings in the map {@code items}. * This constructor converts the keys to a string array and the values to an object array and calls * {@code CompositeDataSupport(javax.management.openmbean.CompositeType, java.lang.String[], java.lang.Object[])}. * * @param compositeType the <i>composite type </i> of this <i>composite data</i> instance; * must not be null. * @param items the mappings of all the item names to their values; * {@code items} must contain all the item names defined in {@code compositeType}; * must not be null or empty. * * @throws IllegalArgumentException {@code compositeType} is null, or * {@code items} is null or empty, or one of the keys in {@code items} is a null * or empty string. * @throws OpenDataException {@code items}' size differs from the * number of items defined in {@code compositeType}, or one of the * keys in {@code items} does not exist as an item name defined in * {@code compositeType}, or one of the values in {@code items} * is not a valid value for the corresponding item as defined in * {@code compositeType}. * @throws ArrayStoreException one or more keys in {@code items} is not of * the class {@code java.lang.String}. */ public CompositeDataSupport(CompositeType compositeType, Map<String, ?> items) throws OpenDataException { this(makeMap(items), compositeType); } private static SortedMap<String, Object> makeMap(Map<String, ?> items) { if (items == null || items.isEmpty()) throw new IllegalArgumentException("Null or empty items map"); SortedMap<String, Object> map = new TreeMap<String, Object>(); for (Object key : items.keySet()) { if (key == null || key.equals("")) throw new IllegalArgumentException("Null or empty item name"); if (!(key instanceof String)) { throw new ArrayStoreException("Item name is not string: " + key); // This can happen because of erasure. The particular // exception is a historical artifact - an implementation // detail that leaked into the API. } map.put((String) key, items.get(key)); } return map; } private CompositeDataSupport(SortedMap<String, Object> items, CompositeType compositeType) throws OpenDataException { // Check compositeType is not null // if (compositeType == null) { throw new IllegalArgumentException("Argument compositeType cannot be null."); } // item names defined in compositeType: Set<String> namesFromType = compositeType.keySet(); Set<String> namesFromItems = items.keySet(); // This is just a comparison, but we do it this way for a better // exception message. if (!namesFromType.equals(namesFromItems)) { Set<String> extraFromType = new TreeSet<String>(namesFromType); extraFromType.removeAll(namesFromItems); Set<String> extraFromItems = new TreeSet<String>(namesFromItems); extraFromItems.removeAll(namesFromType); if (!extraFromType.isEmpty() || !extraFromItems.isEmpty()) { throw new OpenDataException( "Item names do not match CompositeType: " + "names in items but not in CompositeType: " + extraFromItems + "; names in CompositeType but not in items: " + extraFromType); } } // Check each value, if not null, is of the open type defined for the // corresponding item for (String name : namesFromType) { Object value = items.get(name); if (value != null) { OpenType<?> itemType = compositeType.getType(name); if (!itemType.isValue(value)) { throw new OpenDataException("Argument value of wrong type for item " + name + ": value " + value + ", type " + itemType); } } } // Initialize internal fields: compositeType and contents // this.compositeType = compositeType; this.contents = items; } /** * Returns the <i>composite type </i> of this <i>composite data</i> instance. */ public CompositeType getCompositeType() { return compositeType; } /** * Returns the value of the item whose name is {@code key}. * * @throws IllegalArgumentException if {@code key} is a null or empty String. * * @throws InvalidKeyException if {@code key} is not an existing item name for * this {@code CompositeData} instance. */ public Object get(String key) { if ((key == null) || (key.trim().equals(""))) { throw new IllegalArgumentException("Argument key cannot be a null or empty String."); } if (!contents.containsKey(key.trim())) { throw new InvalidKeyException("Argument key=\"" + key.trim() + "\" is not an existing item name for this CompositeData instance."); } return contents.get(key.trim()); } /** * Returns an array of the values of the items whose names are specified by * {@code keys}, in the same order as {@code keys}. * * @throws IllegalArgumentException if an element in {@code keys} is a null * or empty String. * * @throws InvalidKeyException if an element in {@code keys} is not an existing * item name for this {@code CompositeData} instance. */ public Object[] getAll(String[] keys) { if ((keys == null) || (keys.length == 0)) { return new Object[0]; } Object[] results = new Object[keys.length]; for (int i = 0; i < keys.length; i++) { results[i] = this.get(keys[i]); } return results; } /** * Returns {@code true} if and only if this {@code CompositeData} instance contains * an item whose name is {@code key}. * If {@code key} is a null or empty String, this method simply returns false. */ public boolean containsKey(String key) { if ((key == null) || (key.trim().equals(""))) { return false; } return contents.containsKey(key); } /** * Returns {@code true} if and only if this {@code CompositeData} instance * contains an item * whose value is {@code value}. */ public boolean containsValue(Object value) { return contents.containsValue(value); } /** * Returns an unmodifiable Collection view of the item values contained in this * {@code CompositeData} instance. * The returned collection's iterator will return the values in the ascending * lexicographic order of the corresponding * item names. */ public Collection<?> values() { return Collections.unmodifiableCollection(contents.values()); } /** * Compares the specified <var>obj</var> parameter with this * <code>CompositeDataSupport</code> instance for equality. * <p> * Returns {@code true} if and only if all of the following statements are true: * <ul> * <li><var>obj</var> is non null,</li> * <li><var>obj</var> also implements the <code>CompositeData</code> interface,</li> * <li>their composite types are equal</li> * <li>their contents, i.e. (name, value) pairs are equal. If a value contained in * the content is an array, the value comparison is done as if by calling * the {@link java.util.Arrays#deepEquals(Object[], Object[]) deepEquals} method * for arrays of object reference types or the appropriate overloading of * {@code Arrays.equals(e1,e2)} for arrays of primitive types</li> * </ul> * <p> * This ensures that this {@code equals} method works properly for * <var>obj</var> parameters which are different implementations of the * <code>CompositeData</code> interface, with the restrictions mentioned in the * {@link java.util.Collection#equals(Object) equals} * method of the {@code java.util.Collection} interface. * * @param obj the object to be compared for equality with this * <code>CompositeDataSupport</code> instance. * @return <code>true</code> if the specified object is equal to this * <code>CompositeDataSupport</code> instance. */ @Override public boolean equals(Object obj) { if (this == obj) { return true; } // if obj is not a CompositeData, return false if (!(obj instanceof CompositeData)) { return false; } CompositeData other = (CompositeData) obj; // their compositeType should be equal if (!this.getCompositeType().equals(other.getCompositeType())) { return false; } if (contents.size() != other.values().size()) { return false; } for (Map.Entry<String, Object> entry : contents.entrySet()) { Object e1 = entry.getValue(); Object e2 = other.get(entry.getKey()); if (e1 == e2) continue; if (e1 == null) return false; boolean eq = e1.getClass().isArray() ? Arrays.deepEquals(new Object[] { e1 }, new Object[] { e2 }) : e1.equals(e2); if (!eq) return false; } // All tests for equality were successful // return true; } /** * Returns the hash code value for this <code>CompositeDataSupport</code> instance. * <p> * The hash code of a <code>CompositeDataSupport</code> instance is the sum of the hash codes * of all elements of information used in <code>equals</code> comparisons * (ie: its <i>composite type</i> and all the item values). * <p> * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code> * for any two <code>CompositeDataSupport</code> instances <code>t1</code> and <code>t2</code>, * as required by the general contract of the method * {@link Object#hashCode() Object.hashCode()}. * <p> * Each item value's hash code is added to the returned hash code. * If an item value is an array, * its hash code is obtained as if by calling the * {@link java.util.Arrays#deepHashCode(Object[]) deepHashCode} method * for arrays of object reference types or the appropriate overloading * of {@code Arrays.hashCode(e)} for arrays of primitive types. * * @return the hash code value for this <code>CompositeDataSupport</code> instance */ @Override public int hashCode() { int hashcode = compositeType.hashCode(); for (Object o : contents.values()) { if (o instanceof Object[]) hashcode += Arrays.deepHashCode((Object[]) o); else if (o instanceof byte[]) hashcode += Arrays.hashCode((byte[]) o); else if (o instanceof short[]) hashcode += Arrays.hashCode((short[]) o); else if (o instanceof int[]) hashcode += Arrays.hashCode((int[]) o); else if (o instanceof long[]) hashcode += Arrays.hashCode((long[]) o); else if (o instanceof char[]) hashcode += Arrays.hashCode((char[]) o); else if (o instanceof float[]) hashcode += Arrays.hashCode((float[]) o); else if (o instanceof double[]) hashcode += Arrays.hashCode((double[]) o); else if (o instanceof boolean[]) hashcode += Arrays.hashCode((boolean[]) o); else if (o != null) hashcode += o.hashCode(); } return hashcode; } /** * Returns a string representation of this <code>CompositeDataSupport</code> instance. * <p> * The string representation consists of the name of this class (ie <code>javax.management.openmbean.CompositeDataSupport</code>), * the string representation of the composite type of this instance, and the string representation of the contents * (ie list the itemName=itemValue mappings). * * @return a string representation of this <code>CompositeDataSupport</code> instance */ @Override public String toString() { return new StringBuilder().append(this.getClass().getName()).append("(compositeType=") .append(compositeType.toString()).append(",contents=").append(contentString()).append(")") .toString(); } private String contentString() { StringBuilder sb = new StringBuilder("{"); String sep = ""; for (Map.Entry<String, Object> entry : contents.entrySet()) { sb.append(sep).append(entry.getKey()).append("="); String s = Arrays.deepToString(new Object[] { entry.getValue() }); sb.append(s.substring(1, s.length() - 1)); sep = ", "; } sb.append("}"); return sb.toString(); } }