org.elasticsearch.common.Classes Maven / Gradle / Ivy
/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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 org.elasticsearch.common;
import java.lang.reflect.Modifier;
/**
*
*/
public class Classes {
/**
* The package separator character '.'
*/
private static final char PACKAGE_SEPARATOR = '.';
/**
* Return the default ClassLoader to use: typically the thread context
* ClassLoader, if available; the ClassLoader that loaded the ClassUtils
* class will be used as fallback.
*
* Call this method if you intend to use the thread context ClassLoader
* in a scenario where you absolutely need a non-null ClassLoader reference:
* for example, for class path resource loading (but not necessarily for
* Class.forName, which accepts a null ClassLoader
* reference as well).
*
* @return the default ClassLoader (never null)
* @see java.lang.Thread#getContextClassLoader()
*/
public static ClassLoader getDefaultClassLoader() {
ClassLoader cl = null;
try {
cl = Thread.currentThread().getContextClassLoader();
} catch (Throwable ex) {
// Cannot access thread context ClassLoader - falling back to system class loader...
}
if (cl == null) {
// No thread context class loader -> use class loader of this class.
cl = Classes.class.getClassLoader();
}
return cl;
}
/**
* Determine the name of the package of the given class:
* e.g. "java.lang" for the java.lang.String class.
*
* @param clazz the class
* @return the package name, or the empty String if the class
* is defined in the default package
*/
public static String getPackageName(Class clazz) {
String className = clazz.getName();
int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR);
return (lastDotIndex != -1 ? className.substring(0, lastDotIndex) : "");
}
public static String getPackageNameNoDomain(Class clazz) {
String fullPackage = getPackageName(clazz);
if (fullPackage.startsWith("org.") || fullPackage.startsWith("com.") || fullPackage.startsWith("net.")) {
return fullPackage.substring(4);
}
return fullPackage;
}
public static boolean isInnerClass(Class clazz) {
return !Modifier.isStatic(clazz.getModifiers())
&& clazz.getEnclosingClass() != null;
}
public static boolean isConcrete(Class clazz) {
int modifiers = clazz.getModifiers();
return !clazz.isInterface() && !Modifier.isAbstract(modifiers);
}
private Classes() {
}
}