com.ovh.ws.jsonizer.api.base.OvhObject Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jsonizer-api Show documentation
The newest version!
/**
 * Copyright 2012, OVH. All rights reserved.
 *
 * 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.ovh.ws.jsonizer.api.base;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;

public abstract class OvhObject {

	public static boolean equal(Object a, Object b) {
		return a == b || a != null && a.equals(b);
	}

	/**
	 * Generates a hash code for multiple values. The hash code is generated by
	 * calling {@link Arrays#hashCode(Object[])}.
	 */
	public static int hashCode(Object... objects) {
		return Arrays.hashCode(objects);
	}

	/**
	 * Ensures that an object reference passed as a parameter to the calling
	 * method is not null.
	 * 
	 * @param reference
	 *            an object reference
	 * @param errorMessageTemplate
	 *            the exception message to use if the check fails; will
	 *            be converted to a string using {@link String#valueOf(Object)}
	 * @return the non-null reference that was validated
	 * @throws IllegalArgumentException
	 *             if {@code reference} is null
	 */
	public static  T checkNotNull(T reference, String errorMessageTemplate, Object... errorMessageArgs) {
		if (reference == null) {
			throw new IllegalArgumentException(String.format(errorMessageTemplate, errorMessageArgs));
		}

		return reference;
	}

	/**
	 * Returns {@code true} if the given string is null or is the empty string.
	 */
	public static boolean isNullOrEmpty(String string) {
		return string == null || string.length() == 0; // string.isEmpty() in Java 6
	}

	public static URL newUrl(String url) {
		try {
			checkNotNull(url, "Url is required");
			return new URL(url);
		} catch (MalformedURLException e) {
			throw new IllegalArgumentException(e);
		}
	}

	public static ToStringHelper toStringHelper(Object self) {
		return new ToStringHelper(simpleName(self.getClass()));
	}

	private static String simpleName(Class clazz) {
		String name = clazz.getName();

		// the nth anonymous class has a class name ending in "Outer$n"
		// and local inner classes have names ending in "Outer.$1Inner"
		name = name.replaceAll("\\$[0-9]+", "\\$");

		// we want the name of the inner class all by its lonesome
		int start = name.lastIndexOf('$');

		// if this isn't an inner class, just find the start of the
		// top level class name.
		if (start == -1) {
			start = name.lastIndexOf('.');
		}
		return name.substring(start + 1);
	}

}