001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.util;
019
020import java.net.URL;
021import java.net.URLClassLoader;
022
023import org.apache.yetus.audience.InterfaceAudience;
024
025import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
026
027/**
028 * Base class loader that defines couple shared constants used by sub-classes.
029 */
030@InterfaceAudience.Private
031public class ClassLoaderBase extends URLClassLoader {
032
033  protected static final String DEFAULT_LOCAL_DIR = "/tmp/hbase-local-dir";
034  protected static final String LOCAL_DIR_KEY = "hbase.local.dir";
035
036  /**
037   * Parent class loader.
038   */
039  protected final ClassLoader parent;
040
041  /**
042   * Creates a DynamicClassLoader that can load classes dynamically
043   * from jar files under a specific folder.
044   *
045   * @param parent the parent ClassLoader to set.
046   */
047  public ClassLoaderBase(final ClassLoader parent) {
048    super(new URL[]{}, parent);
049    Preconditions.checkNotNull(parent, "No parent classloader!");
050    this.parent = parent;
051  }
052
053}