Java Object to String toString(Object obj)

Description

If the obj is an array, toString() method of Arrays is called.

License

Apache License

Parameter

Parameter	Description
obj	An object. May be an array or <code>null</code>.

Return

String representation of the obj .

Declaration

public static String toString(Object obj) 

Method Source Code

//package com.java2s;
/**/*from ww w  .j a va2s . c o  m*/
 * Copyright 2009-2017 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.Arrays;

public class Main {
    /**
     * If the {@code obj} is an array, toString() method of {@link Arrays} is called. Otherwise
     * {@link Object#toString()} is called. Returns "null" if {@code obj} is <code>null</code>.
     * 
     * @param obj An object. May be an array or <code>null</code>.
     * @return String representation of the {@code obj}.
     */
    public static String toString(Object obj) {
        if (obj == null) {
            return "null";
        }
        final Class<?> clazz = obj.getClass();
        if (!clazz.isArray()) {
            return obj.toString();
        }
        final Class<?> componentType = obj.getClass().getComponentType();
        if (long.class.equals(componentType)) {
            return Arrays.toString((long[]) obj);
        } else if (int.class.equals(componentType)) {
            return Arrays.toString((int[]) obj);
        } else if (short.class.equals(componentType)) {
            return Arrays.toString((short[]) obj);
        } else if (char.class.equals(componentType)) {
            return Arrays.toString((char[]) obj);
        } else if (byte.class.equals(componentType)) {
            return Arrays.toString((byte[]) obj);
        } else if (boolean.class.equals(componentType)) {
            return Arrays.toString((boolean[]) obj);
        } else if (float.class.equals(componentType)) {
            return Arrays.toString((float[]) obj);
        } else if (double.class.equals(componentType)) {
            return Arrays.toString((double[]) obj);
        } else {
            return Arrays.toString((Object[]) obj);
        }
    }

    /**
     * Compares two objects. Returns <code>true</code> if
     * <ul>
     * <li>{@code thisObj} and {@code thatObj} are both <code>null</code></li>
     * <li>{@code thisObj} and {@code thatObj} are instances of the same type and
     * {@link Object#equals(Object)} returns <code>true</code></li>
     * <li>{@code thisObj} and {@code thatObj} are arrays with the same component type and equals()
     * method of {@link Arrays} returns <code>true</code> (not deepEquals())</li>
     * </ul>
     * 
     * @param thisObj The left hand object to compare. May be an array or <code>null</code>
     * @param thatObj The right hand object to compare. May be an array or <code>null</code>
     * @return <code>true</code> if two objects are equal; <code>false</code> otherwise.
     */
    public static boolean equals(Object thisObj, Object thatObj) {
        if (thisObj == null) {
            return thatObj == null;
        } else if (thatObj == null) {
            return false;
        }
        final Class<?> clazz = thisObj.getClass();
        if (!clazz.equals(thatObj.getClass())) {
            return false;
        }
        if (!clazz.isArray()) {
            return thisObj.equals(thatObj);
        }
        final Class<?> componentType = clazz.getComponentType();
        if (long.class.equals(componentType)) {
            return Arrays.equals((long[]) thisObj, (long[]) thatObj);
        } else if (int.class.equals(componentType)) {
            return Arrays.equals((int[]) thisObj, (int[]) thatObj);
        } else if (short.class.equals(componentType)) {
            return Arrays.equals((short[]) thisObj, (short[]) thatObj);
        } else if (char.class.equals(componentType)) {
            return Arrays.equals((char[]) thisObj, (char[]) thatObj);
        } else if (byte.class.equals(componentType)) {
            return Arrays.equals((byte[]) thisObj, (byte[]) thatObj);
        } else if (boolean.class.equals(componentType)) {
            return Arrays.equals((boolean[]) thisObj, (boolean[]) thatObj);
        } else if (float.class.equals(componentType)) {
            return Arrays.equals((float[]) thisObj, (float[]) thatObj);
        } else if (double.class.equals(componentType)) {
            return Arrays.equals((double[]) thisObj, (double[]) thatObj);
        } else {
            return Arrays.equals((Object[]) thisObj, (Object[]) thatObj);
        }
    }
}

Related

1. objToString(Object obj)
2. objToString(Object obj)
3. objToString(Object[] obj)
4. toString(Object o)
5. toString(Object obj)
6. toString(Object object)
7. toString(Object object)
8. toString(Object object)
9. toString(Object object)