UTF8Normalizer.java

/*
 * Copyright (C) 2006-2008 Alfresco Software Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */

package org.alfresco.jlan.util;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * UTF-8 Normalize Class
 * 
 * @author gkspencer
 */
public class UTF8Normalizer {

  // Normalizer method type
  
  public enum NormalizerType { Unknown, Java5, Java6, IBMICU };
  
  // Type of normalizer method
  
  private NormalizerType m_type = NormalizerType.Unknown;
  
  // Normalizer method
  
  private Method m_method;
  
  // Normalizer form parameter field for Java 6 call
  
  private Field m_field;
  
  /**
   * Default constructor
   */
  public UTF8Normalizer() {
    initNormalizer();
    
    if ( isType() == NormalizerType.Unknown)
      throw new RuntimeException("UTf8Normalizer failed to initialize");
  }
  
  /**
   * Normalize a UTF-8 string
   * 
   * @param utf8str String
   * @return String
   */
  public final String normalize( String utf8str) {
    
    // Determine the method to be called

    String normStr = null;
    
    try {
      switch ( isType()) {
  
        // IBM ICU library
        
        case IBMICU:
          
          // Call the compose(String, boolean) method
          
          normStr = (String) m_method.invoke( null, utf8str, false);
          break;
          
        // Java5
          
        case Java5:
          
          // Call the compose(String, boolean, int) method
          
          normStr = (String) m_method.invoke( null, utf8str, false, 0);
          break;
          
        // Java6
          
        case Java6:
          
          // Call the normalize(CharSequence, Normalizer.Form) method
          
          normStr = (String) m_method.invoke( null, utf8str, m_field.get( null));
          break;
          
        // Not initialized
        
        case Unknown:
          throw new RuntimeException("Normalizer is not initialized");
      }
    }
    catch ( InvocationTargetException ex) {
    }
    catch ( IllegalAccessException ex) {
    }
    
    // Return the normalized string
    
    return normStr;
  }
  
  /**
   * Return the normalizer type
   * 
   * @return Normalizer.Type
   */
  public final NormalizerType isType() {
    return m_type;
  }
  
  /**
   * Initialize the normalizer
   */
  private final void initNormalizer() {
    
    // Check if the IBM ICU library is available
    
    try {
      
      // Load the IBM ICU class
      
      Class<?> icuClass = Class.forName( "com.ibm.icu.text.Normalizer");
      
      // Find the compose method
      
      Class<?>[] paramTypes = new Class<?>[2];
      paramTypes[0] = String.class;
      paramTypes[1] = boolean.class;
      
      m_method = icuClass.getMethod( "compose", paramTypes);
      
      // Check if the method is valid
      
      if ( m_method != null) {
        m_type = NormalizerType.IBMICU;
        return;
      }
    }
    catch ( ClassNotFoundException ex) {
    }
    catch (NoSuchMethodException ex) {
    }
    
    // Check the Java version and use the appropriate method
    
    String javaVer = System.getProperty("java.specification.version");
    
    if ( javaVer.equals("1.5")) {
      
      try {
        
        // Load the sun.text.Normalizer class
        
        Class<?> sunClass = Class.forName("sun.text.Normalizer");
        
        // Find the compose method
        
        Class<?>[] paramTypes = new Class<?>[3];
        paramTypes[0] = String.class;
        paramTypes[1] = boolean.class;
        paramTypes[2] = int.class;
        
        m_method = sunClass.getMethod("compose", paramTypes);

        // Check if the method is valid
        
        if ( m_method != null) {
          m_type = NormalizerType.Java5;
          return;
        }
      }
      catch ( ClassNotFoundException ex) {
      }
      catch (NoSuchMethodException ex) {
      }
    }
    else if ( javaVer.equals("1.6")) {
      
      try {
        
        // Load the java.text.Normalizer class
        
        Class<?> java6Class = Class.forName("java.text.Normalizer");
        
        // Load the Normalizer.Form class, used as a parameter
        
        Class<?> normFormClass = Class.forName("java.text.Normalizer$Form");
        
        // Get the required Normalizer.Form value
        
        m_field = normFormClass.getField("NFD");
        
        // Find the compose method
        
        Class<?>[] paramTypes = new Class<?>[2];
        paramTypes[0] = CharSequence.class;
        paramTypes[1] = normFormClass;
        
        m_method = java6Class.getMethod("normalize", paramTypes);

        // Check if the method is valid
        
        if ( m_method != null) {
          m_type = NormalizerType.Java6;
          return;
        }
      }
      catch ( ClassNotFoundException ex) {
      }
      catch (NoSuchMethodException ex) {
      }
      catch (NoSuchFieldException ex) {
      }
    }
  }
}