StringUtils.java

/*!
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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 Lesser General Public License for more details.
 *
 * Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.gwt.widgets.client.utils.string;

// see: http://commons.apache.org/lang/apidocs/org/apache/commons/lang/StringUtils.html

public class StringUtils {

  public static boolean isEmpty( String str ) {
    return null == str || "".equals( str.trim() ); //$NON-NLS-1$
  }

  public static String defaultString( String str, String xdefault ) {
    return StringUtils.isEmpty( str ) ? xdefault : str;
  }

  public static String defaultString( String str ) {
    return StringUtils.isEmpty( str ) ? "" : str; //$NON-NLS-1$
  }

  public static String defaultIfEmpty( String str, String xdefault ) {
    return StringUtils.isEmpty( str ) ? xdefault : str;
  }

  public static String addStringToInt( String strAddend, int addend ) {
    return Integer.toString( Integer.parseInt( strAddend ) + addend );
  }

  public static String multiplyStringWithInt( String strMultiplicand, int multiplier ) {
    return Integer.toString( Integer.parseInt( strMultiplicand ) * multiplier );
  }

  public static String divideStringWithInt( String strDividend, int divisor ) {
    return Integer.toString( Integer.parseInt( strDividend ) / divisor );
  }

  public static boolean containsAnyChars( String str, String checkChars ) {
    if ( StringUtils.isEmpty( str ) || StringUtils.isEmpty( checkChars ) ) {
      return false;
    }
    for ( int i = 0; i < checkChars.length(); i++ ) {
      if ( str.indexOf( checkChars.charAt( i ) ) >= 0 ) {
        return true;
      }
    }
    return false;
  }

  // MAX_INT = 2147483647
  private static final String MATCH_POSITIVE_INTEGER_RE = "^\\s*[0-9]{1,10}\\s*$"; //$NON-NLS-1$

  public static boolean isPositiveInteger( String strInt ) {
    int length = strInt.length();
    if ( length > 10 ) {
      return false; // MAX_INT has 10 digits
    } else if ( length == 10 ) {
      // This is an execution-expensive path, since it relies on exception
      // processing to determine if strInt is an Integer or not. Minimize
      // the number of times this else-if is entered
      if ( strInt.matches( MATCH_POSITIVE_INTEGER_RE ) ) {
        try {
          Integer.parseInt( strInt );
          return true;
        } catch ( NumberFormatException ignore ) {
          //ignore
        }
      }
      return false;
    } else {
      return strInt.matches( MATCH_POSITIVE_INTEGER_RE );
    }
  }
  
  public static int countMatches(String str, String sub) {
    if (isEmpty( str ) || isEmpty( sub )){
      return 0;
    }
    int count = 0;
    int idx = 0;
    while ((idx = str.indexOf(sub, idx)) != -1) {
        count++;
        idx += sub.length();
    }
    return count;
  }
}