hbase-common/src/main/java/org/apache/hadoop/hbase/util/Classes.java

   1 /*
   2  * Copyright The Apache Software Foundation
   3  *
   4  * Licensed to the Apache Software Foundation (ASF) under one
   5  * or more contributor license agreements.  See the NOTICE file
   6  * distributed with this work for additional information
   7  * regarding copyright ownership.  The ASF licenses this file
   8  * to you under the Apache License, Version 2.0 (the
   9  * "License"); you may not use this file except in compliance
  10  * with the License.  You may obtain a copy of the License at
  11  *
  12  *     http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 package org.apache.hadoop.hbase.util;
  21
  22 import org.apache.yetus.audience.InterfaceAudience;
  23
  24 /**
  25  * Utilities for class manipulation.
  26  */
  27 @InterfaceAudience.Private
  28 public class Classes {
  29
  30   /**
  31    * Equivalent of {@link Class#forName(String)} which also returns classes for
  32    * primitives like <code>boolean</code>, etc.
  33    *
  34    * @param className
  35    *          The name of the class to retrieve. Can be either a normal class or
  36    *          a primitive class.
  37    * @return The class specified by <code>className</code>
  38    * @throws ClassNotFoundException
  39    *           If the requested class can not be found.
  40    */
  41   public static Class<?> extendedForName(String className)
  42       throws ClassNotFoundException {
  43     Class<?> valueType;
  44     if (className.equals("boolean")) {
  45       valueType = boolean.class;
  46     } else if (className.equals("byte")) {
  47       valueType = byte.class;
  48     } else if (className.equals("short")) {
  49       valueType = short.class;
  50     } else if (className.equals("int")) {
  51       valueType = int.class;
  52     } else if (className.equals("long")) {
  53       valueType = long.class;
  54     } else if (className.equals("float")) {
  55       valueType = float.class;
  56     } else if (className.equals("double")) {
  57       valueType = double.class;
  58     } else if (className.equals("char")) {
  59       valueType = char.class;
  60     } else {
  61       valueType = Class.forName(className);
  62     }
  63     return valueType;
  64   }
  65
  66   public static String stringify(Class<?>[] classes) {
  67     StringBuilder buf = new StringBuilder();
  68     if (classes != null) {
  69       for (Class<?> c : classes) {
  70         if (buf.length() > 0) {
  71           buf.append(",");
  72         }
  73         buf.append(c.getName());
  74       }
  75     } else {
  76       buf.append("NULL");
  77     }
  78     return buf.toString();
  79   }
  80
  81   @SuppressWarnings("unchecked")
  82   public static <T> Class<T> cast(Class<?> clazz) {
  83     return (Class<T>) clazz;
  84   }
  85 }