Java tutorial
/* * Copyright (c) 2000, 2007, 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.util.Collection; // jmx import // /** * The {@code CompositeData} interface specifies * the behavior of a specific type of complex <i>open data</i> objects * which represent <i>composite data</i> structures. * * * @since 1.5 */ public interface CompositeData { /** * Returns the <i>composite type </i> of this <i>composite data</i> instance. * * @return the type of this CompositeData. */ public CompositeType getCompositeType(); /** * Returns the value of the item whose name is {@code key}. * * @param key the name of the item. * * @return the value associated with this 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); /** * Returns an array of the values of the items whose names * are specified by {@code keys}, in the same order as {@code keys}. * * @param keys the names of the items. * * @return the values corresponding to the 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); /** * 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. * * @param key the key to be tested. * * @return true if this {@code CompositeData} contains the key. */ public boolean containsKey(String key); /** * Returns {@code true} if and only if this {@code CompositeData} instance contains an item * whose value is {@code value}. * * @param value the value to be tested. * * @return true if this {@code CompositeData} contains the value. */ public boolean containsValue(Object 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. * * @return the values. */ public Collection<?> values(); /** * Compares the specified <var>obj</var> parameter with this * {@code CompositeData} 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} 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} 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 CompositeData} instance. * @return {@code true} if the specified object is equal to this * {@code CompositeData} instance. */ public boolean equals(Object obj); /** * Returns the hash code value for this {@code CompositeData} instance. * <p> * The hash code of a {@code CompositeData} instance is the sum of the hash codes * of all elements of information used in {@code equals} comparisons * (ie: its <i>composite type</i> and all the item values). * <p> * This ensures that {@code t1.equals(t2)} implies that {@code t1.hashCode()==t2.hashCode()} * for any two {@code CompositeData} instances {@code t1} and {@code t2}, * 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 CompositeData} instance */ public int hashCode(); /** * Returns a string representation of this {@code CompositeData} instance. * <p> * The string representation consists of the name of the implementing class, * 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 CompositeData} instance */ public String toString(); }