Removes null objects from the Collection. - Java java.util

Java examples for java.util:Collection Element Remove

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Description

Removes null objects from the Collection.

Demo Code

/**//www .  ja  v  a 2  s. com
 *  Copyright 2009 Welocalize, Inc. 
 *  
 *  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.
 *  
 */
//package com.java2s;
import java.util.Collection;
import java.util.Iterator;

import java.util.List;
import java.util.ArrayList;

public class Main {
    public static void main(String[] argv) {
        Collection p_collection = java.util.Arrays.asList("asdf",
                "java2s.com");
        System.out.println(removeNulls(p_collection));
    }

    /**
     * Removes null objects from the Collection.
     * @param p_collection a Collection
     * @returns true if one or more null objects were removed.
     */
    public static boolean removeNulls(Collection p_collection) {
        if (p_collection == null) {
            return false;
        }
        boolean removed = false;
        Iterator it = p_collection.iterator();
        while (it.hasNext()) {
            Object o = it.next();
            if (o == null) {
                removed = true;
                it.remove();
            }
        }
        return removed;
    }

    /**
     * Removes the element at the specified position in 
     * the collection. 
     * Shifts any subsequent elements to the left 
     * (subtracts one from their indices). 
     * Returns the element that was removed from the Collection.
     * @param p_collection a Collection
     * @param p_index the index of the element to removed.
     * @param p_numberOfObjects the number of objects to remove.
     * @returns a collection with the elements at p_index removed.
     */
    public static Collection remove(Collection p_collection, int p_index,
            int p_numberOfObjects) {
        if (p_collection == null) {
            return null;
        }
        List returnList = new ArrayList(p_collection.size()
                - p_numberOfObjects);
        Iterator it = p_collection.iterator();
        for (int i = 0; it.hasNext(); i++) {
            if (i < p_index || i >= p_index + p_numberOfObjects) {
                returnList.add(it.next());
            } else {
                it.next();
            }
        }
        return returnList;
    }
}

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