/*
    * $Id: ParseHelper.java 113 2004-10-22 19:22:56Z josem $
    *
    * Tarsis
    * Copyright (C) 2002 Talika Open Source Group
    *
    * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  package org.talika.commons.util;
  
  import java.text.NumberFormat;
  import java.text.DateFormat;
  import java.text.ParseException;
  import java.util.Collections;
  import java.util.Date;
  import java.util.HashSet;
  import java.util.Set;
  import java.io.File;
  
  /**
   *
   * @author  Jose M. Palomar
   * @version $Revision: 113 $
   */
  public final class ParseHelper {
  
      // Constants
      /**
       * Constant string value for <code>true</code>.
       */
      public static final String TRUE_VALUE = Boolean.toString(true);
  
      /**
       * Constant string value for <code>true</code>.
       */
      public static final String FALSE_VALUE = Boolean.toString(false);
  
      // Fields
      /**
       * Singleton instance.
       */
      private static final ParseHelper INSTANCE = new ParseHelper();
  
      /**
       * Set of classes supported by this helper.
       */
      private Set supportedClasses;
  
      /**
       * Integer parser.
       */
      private NumberFormat integerFormat;
  
      /**
       * Decimal parser.
       */
      private NumberFormat decimalFormat;
  
      /**
       * Date and time parser.
       */
      private DateFormat dateTimeFormat;
  
      /**
       * Time parser.
       */
      private DateFormat timeFormat;
  
      /**
       * Date parser.
       */
      private DateFormat dateFormat;
  
      // Constructors
      /**
       * Constructs a new <code>ParseHelper</code> object.
       */
      private ParseHelper() {
  
          this.integerFormat = NumberFormat.getNumberInstance();
          this.integerFormat.setParseIntegerOnly(true);
          this.decimalFormat = NumberFormat.getNumberInstance();
          this.dateTimeFormat = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT);
          this.dateTimeFormat.setLenient(false);
          this.dateFormat = DateFormat.getDateInstance(DateFormat.SHORT);
         this.dateFormat.setLenient(false);
         this.timeFormat = DateFormat.getTimeInstance(DateFormat.SHORT);
         this.timeFormat.setLenient(false);
 
         /* Supported classes */
         this.supportedClasses = new HashSet();
         this.supportedClasses.add(java.lang.String.class);
         this.supportedClasses.add(java.lang.Integer.class);
         this.supportedClasses.add(java.lang.Long.class);
         this.supportedClasses.add(java.lang.Float.class);
         this.supportedClasses.add(java.lang.Double.class);
         this.supportedClasses.add(java.lang.Boolean.class);
         this.supportedClasses.add(java.util.Date.class);
         this.supportedClasses.add(java.sql.Date.class);
         this.supportedClasses.add(java.sql.Time.class);
         this.supportedClasses.add(java.sql.Timestamp.class);
         this.supportedClasses.add(java.io.File.class);
         this.supportedClasses = Collections.unmodifiableSet(this.supportedClasses);
 
     }
 
     // Methods
     /**
      * Obtains a <code>ParseHelper</code> instance.
      *
      * @return ParseHelper instance.
      */
     public static ParseHelper getInstance() {
         return INSTANCE;
     }
 
     /**
      * Parses a string text to produce an object of a target type.
      *
      * @param type Class target type.
      * @param text String text to parse.
      * @return Object an <code>Object</code> of target type parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Object parseObject(Class type, String text) throws ParseException {
 
         if (type.getName().equals("java.lang.String")) {
             return text;
         }
         if (type.getName().equals("java.lang.Integer")) {
             return parseInteger(text);
         }
         else if (type.getName().equals("java.lang.Long")) {
             return parseLong(text);
         }
         else if (type.getName().equals("java.lang.Float")) {
             return parseFloat(text);
         }
         else if (type.getName().equals("java.lang.Double")) {
             return parseDouble(text);
         }
         else if (type.getName().equals("java.lang.Boolean")) {
             return parseBoolean(text);
         }
         else if (type.getName().equals("java.util.Date")) {
             return parseDateTime(text);
         }
         else if (type.getName().equals("java.sql.Date")) {
             return parseDate(text);
         }
         else if (type.getName().equals("java.sql.Time")) {
             return parseTime(text);
         }
         else if (type.getName().equals("java.sql.Timestamp")) {
             return parseDateTime(text);
         }
         else if (type.getName().equals("java.io.File")) {
             return parseFile(text);
         }
         else {
             throw new ParseException("Unsuported field type " + type.getName(), 0);
         }
 
     }
 
     /**
      * Parses a string text to produce an <code>Integer</code> object.
      *
      * @param text String text to parse.
      * @return Integer an <code>Integer</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Integer parseInteger(String text) throws ParseException {
         return new Integer(this.integerFormat.parse(text).intValue());
     }
 
     /**
      * Parses a string text to produce a <code>Long</code> object.
      *
      * @param text String text to parse.
      * @return Long a <code>Long</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Long parseLong(String text) throws ParseException {
         return new Long(this.integerFormat.parse(text).longValue());
     }
 
     /**
      * Parses a string text to produce a <code>Float</code> object.
      *
      * @param text String text to parse.
      * @return Float a <code>Float</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Float parseFloat(String text) throws ParseException {
         return new Float(this.decimalFormat.parse(text).floatValue());
     }
 
     /**
      * Parses a string text to produce an <code>Double</code> object.
      *
      * @param text String text to parse.
      * @return Double a <code>Double</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Double parseDouble(String text) throws ParseException {
         return new Double(this.decimalFormat.parse(text).doubleValue());
     }
 
     /**
      * Parses a string text to produce an <code>Boolean</code> object.
      *
      * @param text String text to parse.
      * @return Boolean a <code>Boolean</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Boolean parseBoolean(String text) throws ParseException {
 
         if (text.equalsIgnoreCase(TRUE_VALUE)) {
             return Boolean.TRUE;
         }
         else if (text.equalsIgnoreCase(FALSE_VALUE)) {
             return Boolean.FALSE;
         }
         else {
             throw new ParseException("Invalid boolean value " + text, 0);
         }
 
     }
 
     /**
      * Parses a string text to produce a <code>Date</code> object.
      *
      * @param text String text to parse.
      * @return Date a <code>Date</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Date parseDateTime(String text) throws ParseException {
         return this.dateTimeFormat.parse(text);
     }
 
     /**
      * Parses a string text to produce a <code>Date</code> object.
      *
      * @param text String text to parse.
      * @return Date a <code>Date</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Date parseDate(String text) throws ParseException {
         return this.dateFormat.parse(text);
     }
 
     /**
      * Parses a string text to produce a <code>Date</code> object.
      *
      * @param text String text to parse.
      * @return Date a <code>Date</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public Date parseTime(String text) throws ParseException {
         return this.timeFormat.parse(text);
     }
 
     /**
      * Parses a string text to produce a <code>File</code> object.
      *
      * @param text String text to parse.
      * @return File a <code>File</code> object parsed from string.
      * @throws ParseException if the specified string cannot be parsed.
      */
     public File parseFile(String text) throws ParseException {
 
         File file = new File(text);
         if (!file.exists()) {
             file = null;
         }
 
         return file;
 
     }
 
     /**
      * Returns a <code>Set</code> of classes supported by this helper.
      *
      * @return Set of classes supported.
      */
     public Set getSupportedClasses() {
         return this.supportedClasses;
     }
 
 }