content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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
   *
   *     https://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.apache.avro.util;
  
  public class ClassUtils {
  
    private ClassUtils() {
    }
  
    /**
     * Loads a class using the class loader. 1. The class loader of the current
     * class is being used. 2. The thread context class loader is being used. If
     * both approaches fail, returns null.
     *
     * @param className The name of the class to load.
     * @return The class or null if no class loader could load the class.
     */
    public static Class<?> forName(String className) throws ClassNotFoundException {
      return ClassUtils.forName(ClassUtils.class, className);
    }
  
    /**
     * Loads a class using the class loader. 1. The class loader of the context
     * class is being used. 2. The thread context class loader is being used. If
     * both approaches fail, returns null.
     *
     * @param contextClass The name of a context class to use.
     * @param className    The name of the class to load
     * @return The class or null if no class loader could load the class.
     */
    public static Class<?> forName(Class<?> contextClass, String className) throws ClassNotFoundException {
      Class<?> c = null;
      if (contextClass.getClassLoader() != null) {
        c = forName(className, contextClass.getClassLoader());
      }
      if (c == null && Thread.currentThread().getContextClassLoader() != null) {
        c = forName(className, Thread.currentThread().getContextClassLoader());
      }
      if (c == null) {
        throw new ClassNotFoundException("Failed to load class" + className);
      }
      return c;
    }
  
    /**
     * Loads a class using the class loader. 1. The class loader of the context
     * class is being used. 2. The thread context class loader is being used. If
     * both approaches fail, returns null.
     *
     * @param classLoader The classloader to use.
     * @param className   The name of the class to load
     * @return The class or null if no class loader could load the class.
     */
    public static Class<?> forName(ClassLoader classLoader, String className) throws ClassNotFoundException {
      Class<?> c = null;
      if (classLoader != null) {
        c = forName(className, classLoader);
      }
      if (c == null && Thread.currentThread().getContextClassLoader() != null) {
        c = forName(className, Thread.currentThread().getContextClassLoader());
      }
      if (c == null) {
        throw new ClassNotFoundException("Failed to load class" + className);
      }
      return c;
    }
  
    /**
     * Loads a {@link Class} from the specified {@link ClassLoader} without throwing
     * {@link ClassNotFoundException}.
     *
     * @param className
     * @param classLoader
     * @return
     */
    private static Class<?> forName(String className, ClassLoader classLoader) {
      Class<?> c = null;
      if (classLoader != null && className != null) {
        try {
          c = Class.forName(className, true, classLoader);
        } catch (ClassNotFoundException e) {
          // Ignore and return null
        }
      }
      return c;
    }
  }
  