Converts the given array into a Map . - Android java.lang

Android examples for java.lang:array convert

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Description

Converts the given array into a Map .

Demo Code

/*//www  .  jav  a  2s.  co m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.HashMap;
import java.util.Map;

public class Main {
    /**
     * <p>Converts the given array into a {@link Map}. Each element of the array
     * must be either a {@link Map.Entry} or an Array, containing at least two
     * elements, where the first element is used as key and the second as
     * value.</p>
     *
     * <p>This method can be used to initialize:</p>
     * <pre>
     * // Create a Map mapping colors.
     * Map colorMap = MapUtils.toMap(new String[][] {{
     *     {"RED", "#FF0000"},
     *     {"GREEN", "#00FF00"},
     *     {"BLUE", "#0000FF"}});
     * </pre>
     *
     * <p>This method returns {@code null} for a {@code null} input array.</p>
     *
     * @param array  an array whose elements are either a {@link Map.Entry} or
     *  an Array containing at least two elements, may be {@code null}
     * @return a {@code Map} that was created from the array
     * @throws IllegalArgumentException  if one element of this Array is
     *  itself an Array containing less then two elements
     * @throws IllegalArgumentException  if the array contains elements other
     *  than {@link Map.Entry} and an Array
     */
    public static Map<Object, Object> toMap(final Object[] array) {
        if (array == null) {
            return null;
        }
        final Map<Object, Object> map = new HashMap<Object, Object>(
                (int) (array.length * 1.5));
        for (int i = 0; i < array.length; i++) {
            final Object object = array[i];
            if (object instanceof Map.Entry<?, ?>) {
                final Map.Entry<?, ?> entry = (Map.Entry<?, ?>) object;
                map.put(entry.getKey(), entry.getValue());
            } else if (object instanceof Object[]) {
                final Object[] entry = (Object[]) object;
                if (entry.length < 2) {
                    throw new IllegalArgumentException("Array element " + i
                            + ", '" + object
                            + "', has a length less than 2");
                }
                map.put(entry[0], entry[1]);
            } else {
                throw new IllegalArgumentException("Array element " + i
                        + ", '" + object
                        + "', is neither of type Map.Entry nor an Array");
            }
        }
        return map;
    }
}

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