Java Array Merge mergeStringArrays(String[] array1, String[] array2)

Description

Merge the given String arrays into one, with overlapping array elements only included once.

License

Apache License

Parameter

Parameter	Description
array1	the first array (can be <code>null</code>)
array2	the second array (can be <code>null</code>)

Return

the new array (null if both given arrays were null)

Declaration

public static String[] mergeStringArrays(String[] array1, String[] array2) 

Method Source Code

//package com.java2s;
/*/*from   w  ww  .ja  v  a 2s  .  co  m*/
 * Copyright 2002-2011 the original author or authors.
 *
 * 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.*;

public class Main {
    /**
     * Merge the given String arrays into one, with overlapping
     * array elements only included once.
     * <p>The order of elements in the original arrays is preserved
     * (with the exception of overlapping elements, which are only
     * included on their first occurrence).
     * @param array1 the first array (can be <code>null</code>)
     * @param array2 the second array (can be <code>null</code>)
     * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
     */
    public static String[] mergeStringArrays(String[] array1, String[] array2) {
        if (isObjectEmpty(array1)) {
            return array2;
        }
        if (isObjectEmpty(array2)) {
            return array1;
        }
        List<String> result = new ArrayList<String>();
        result.addAll(Arrays.asList(array1));
        for (String str : array2) {
            if (!result.contains(str)) {
                result.add(str);
            }
        }
        return toStringArray(result);
    }

    /**
     * Determine whether the given array is empty:
     * i.e. <code>null</code> or of zero length.
     * @param array the array to check
     */
    public static boolean isObjectEmpty(Object[] array) {
        return (array == null || array.length == 0);
    }

    /**
     * Copy the given Collection into a String array.
     * The Collection must contain String elements only.
     * @param collection the Collection to copy
     * @return the String array (<code>null</code> if the passed-in
     * Collection was <code>null</code>)
     */
    public static String[] toStringArray(Collection<String> collection) {
        if (collection == null) {
            return null;
        }
        return collection.toArray(new String[collection.size()]);
    }

    /**
     * Copy the given Enumeration into a String array.
     * The Enumeration must contain String elements only.
     * @param enumeration the Enumeration to copy
     * @return the String array (<code>null</code> if the passed-in
     * Enumeration was <code>null</code>)
     */
    public static String[] toStringArray(Enumeration<String> enumeration) {
        if (enumeration == null) {
            return null;
        }
        List<String> list = Collections.list(enumeration);
        return list.toArray(new String[list.size()]);
    }
}

Related

1. mergeStringArray(String[] inp1, String[] inp2)
2. mergeStringArray(String[] input)
3. mergeStringArrayFromIndex(String[] arrayString, int i)
4. mergeStringArrays(String array1[], String array2[])
5. mergeStringArrays(String array1[], String array2[], String array3[])
6. mergeStringArrays(String[][] arrayOfArrays)
7. mergeStrings(String[] x, String[] y)
8. mergeToArray(T... args)