Java Collection Contain containsObjectIdentity(Collection collection, Object object)

Description

Returns true if the given Collection contains the given object.

License

Apache License

Parameter

Parameter	Description
collection	a parameter
object	a parameter

Declaration

public static <E> boolean containsObjectIdentity(Collection<E> collection, Object object) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright 2011 Danny Kunz/*from   ww  w .j  av a2 s.c  o  m*/
 * 
 * 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.util.Collection;
import java.util.Iterator;

public class Main {
    /**
     * Returns true if the given {@link Collection} contains the given object. Contains uses the "object == element" instead of the
     * "equals" method to determine the object identity.
     * 
     * @param collection
     * @param object
     * @return
     */
    public static <E> boolean containsObjectIdentity(Collection<E> collection, Object object) {
        return indexOfObjectIdentity(collection, object) >= 0;
    }

    /**
     * Returns the index position of the first occurring object within the {@link Collection}. Comparisons uses the
     * "object == element" instead of the "equals" method to determine the object identity.
     * 
     * @param collection
     * @param object
     * @return index position of the first matching element;-1 if no element is matching
     */
    public static <E> int indexOfObjectIdentity(Collection<E> collection, Object object) {
        //
        int retval = -1;

        //
        if (collection != null) {
            Iterator<E> iterator = collection.iterator();
            if (iterator != null) {
                int indexPosition = 0;
                while (retval < 0 && iterator.hasNext()) {
                    //
                    E element = iterator.next();
                    if (element == object) {
                        retval = indexPosition;
                    }

                    //
                    indexPosition++;
                }
            }
        }

        //
        return retval;
    }
}

Related

1. containsNull(Collection