Compare method for more then one Comparable object. - Java Reflection

Java examples for Reflection:Method

  1. HOME
  2. Java
  3. Reflection
  4. Method

Description

Compare method for more then one Comparable object.

Demo Code

/*/* w  w  w .  j a va2s.c  o m*/
 * Copyright 2014 Lukas Benda <lbenda at lbenda.cz>.
 *
 * 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;

public class Main {
    /** Compare method for more then one object. If the first object is equal (or both are null)
     * then is compare next item. If both object in arra is null then is equal, if one isn't null then is greater. */
    public static int compareArrayNull(Comparable[] o1, Comparable[] o2) {
        if (o1 == null) {
            throw new NullPointerException("Parameter o1 is null");
        }
        if (o2 == null) {
            throw new NullPointerException("Parameter o2 is null");
        }
        if (o1.length != o2.length) {
            throw new IllegalArgumentException(
                    "The parameter o1 and o2 have different length");
        }
        for (int i = 0; i < o1.length; i++) {
            if (!nullEquals(o1[i], o2[i])) {
                if (o1[i] == null) {
                    return -1;
                } else if (o2[i] == null) {
                    return 1;
                }
                if (!o1[i].equals(o2[i])) {
                    return o1[i].compareTo(o2[i]);
                }
            }
        }
        return 0;
    }

    /** This method run equals on two object. If both is null, then is equal */
    public static boolean nullEquals(Object o1, Object o2) {
        if (o1 == null) {
            return o2 == null;
        }
        return o1.equals(o2);
    }
}

Related Tutorials