Java String Empty to Null nullSafeToString(Object obj)

Description

Convert the supplied Object to a String using the following algorithm.

License

Open Source License

Parameter

Parameter	Description
obj	the object to convert to a String; may be null

Return

a String representation of the supplied object

Declaration

public static String nullSafeToString(Object obj) 

Method Source Code

//package com.java2s;
/*/*  w  w  w .  ja  v  a 2  s . c om*/
 * Copyright 2015-2017 the original author or authors.
 *
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License v2.0 which
 * accompanies this distribution and is available at
 *
 * http://www.eclipse.org/legal/epl-v20.html
 */

import java.util.Arrays;

public class Main {
    /**
     * Convert the supplied {@code Object} to a {@code String} using the
     * following algorithm.
     *
     * <ul>
     * <li>If the supplied object is {@code null}, this method returns {@code "null"}.</li>
     * <li>If the supplied object is a primitive array, the appropriate
     * {@code Arrays#toString(...)} variant will be used to convert it to a String.</li>
     * <li>If the supplied object is an object array, {@code Arrays#deepToString(Object[])}
     * will be used to convert it to a String.</li>
     * <li>Otherwise, the result of invoking {@code toString()} on the object
     * will be returned.</li>
     * </ul>
     *
     * @param obj the object to convert to a String; may be {@code null}
     * @return a String representation of the supplied object
     * @see Arrays#deepToString(Object[])
     * @see ClassUtils#nullSafeToString(Class...)
     */
    public static String nullSafeToString(Object obj) {
        if (obj == null) {
            return "null";
        } else if (obj.getClass().isArray()) {
            if (obj.getClass().getComponentType().isPrimitive()) {
                if (obj instanceof boolean[]) {
                    return Arrays.toString((boolean[]) obj);
                }
                if (obj instanceof char[]) {
                    return Arrays.toString((char[]) obj);
                }
                if (obj instanceof short[]) {
                    return Arrays.toString((short[]) obj);
                }
                if (obj instanceof byte[]) {
                    return Arrays.toString((byte[]) obj);
                }
                if (obj instanceof int[]) {
                    return Arrays.toString((int[]) obj);
                }
                if (obj instanceof long[]) {
                    return Arrays.toString((long[]) obj);
                }
                if (obj instanceof float[]) {
                    return Arrays.toString((float[]) obj);
                }
                if (obj instanceof double[]) {
                    return Arrays.toString((double[]) obj);
                }
            }
            return Arrays.deepToString((Object[]) obj);
        }
        // else
        return obj.toString();
    }
}

Related

1. emptyToNull(String text)
2. emptyToNull(String val)
3. emptyToNull(String value)
4. emptyToString(String str, String returnStr)
5. isHtmlNull(String str)
6. nvlStr(Object o, String valueIfNull)
7. parseCommas(String s, boolean ignoreNulls)
8. removeNulls(String... strings)
9. toString(Object object, String nullStr)