ClassLoadUtil.java

/*
 * 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
 *
 * 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.apache.geode.internal;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class ClassLoadUtil {

  static Map primTypes;
  static Map wrapperTypes;

  static {

    if (primTypes == null) {
      Map ptMap = new HashMap();
      ptMap.put(boolean.class.getName(), boolean.class);
      ptMap.put(char.class.getName(), char.class);
      ptMap.put(byte.class.getName(), byte.class);
      ptMap.put(short.class.getName(), short.class);
      ptMap.put(int.class.getName(), int.class);
      ptMap.put(long.class.getName(), long.class);
      ptMap.put(float.class.getName(), float.class);
      ptMap.put(double.class.getName(), double.class);
      ptMap.put(void.class.getName(), void.class);
      // Do this at the end to support multiple threads without synchronizing
      primTypes = ptMap;
    }

    if (wrapperTypes == null) {
      Map wtMap = new HashMap();
      wtMap.put(boolean.class.getName(), Boolean.class);
      wtMap.put(char.class.getName(), Character.class);
      wtMap.put(byte.class.getName(), Byte.class);
      wtMap.put(short.class.getName(), Short.class);
      wtMap.put(int.class.getName(), Integer.class);
      wtMap.put(long.class.getName(), Long.class);
      wtMap.put(float.class.getName(), Float.class);
      wtMap.put(double.class.getName(), Double.class);
      // Do this at the end to support multiple threads without synchronizing
      wrapperTypes = wtMap;
    }
  }

  /**
   * Resolve the class from the given name. Supports primitive types, too.
   */
  public static Class classFromName(String className) throws ClassNotFoundException {
    Class result = checkForPrimType(className);
    if (result == null) {
      result = ClassPathLoader.getLatest().forName(className);
    }
    return result;
  }

  /**
   * Resolve the method from the given qualified name.
   */
  public static Method methodFromName(String fullyQualifiedMethodName, Class[] parameterTypes)
      throws ClassNotFoundException, NoSuchMethodException, SecurityException {
    int classIndex = fullyQualifiedMethodName.lastIndexOf('.');
    if (classIndex <= 0) {
      throw new ClassNotFoundException(
          "Static creation function [" + fullyQualifiedMethodName + "] should be fully qualified");
    }
    String className = fullyQualifiedMethodName.substring(0, classIndex);
    if (checkForPrimType(className) != null) {
      throw new NoSuchMethodException(className + " cannot be one of the primitive types");
    }
    String methodName = fullyQualifiedMethodName.substring(classIndex + 1);
    Class result = ClassPathLoader.getLatest().forName(className);
    return result.getMethod(methodName, parameterTypes);
  }

  /**
   * Resolve the method from the given qualified name. Only zero argument methods are supported.
   */
  public static Method methodFromName(String fullyQualifiedMethodName)
      throws ClassNotFoundException, NoSuchMethodException, SecurityException {
    return methodFromName(fullyQualifiedMethodName, (Class[]) null);
  }

  /**
   * If the argument className is the name of a primitive type (including "void"), return the
   * primitive type class (ex, boolean.class). Otherwise, return null.
   */
  public static Class checkForPrimType(String className) {

    return (Class) primTypes.get(className);
  }

  /**
   * If the argument className is the name of a primitive type (not including "void"), return the
   * wrapper class for that type (ex, Boolean.class). Otherwise, return null.
   */
  public static Class checkForWrapperType(String className) {

    return (Class) wrapperTypes.get(className);
  }

}