Gets strong-type-value property from a standard Properties : Properties « Collections « Java Tutorial

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import java.security.SecureRandom;
import java.util.Properties;
import java.util.Random;

public class StringUtils
{

  /**
   *  Gets an integer-valued property from a standard Properties
   *  list.  If the value does not exist, or is a non-integer, returns defVal.
   *
   *  @since 2.1.48.
   *  @param props The property set to look through
   *  @param key   The key to look for
   *  @param defVal If the property is not found or is a non-integer, returns this value.
   *  @return The property value as an integer (or defVal).
   */
  public static int getIntegerProperty( Properties props,
                                        String key,
                                        int defVal )
  {
      String val = props.getProperty( key );

      return parseIntParameter( val, defVal );
  }

  /**
   *  Gets a boolean property from a standard Properties list.
   *  Returns the default value, in case the key has not been set.
   *  
   *  The possible values for the property are "true"/"false", "yes"/"no", or
   *  "on"/"off".  Any value not recognized is always defined as "false".
   *
   *  @param props   A list of properties to search.
   *  @param key     The property key.
   *  @param defval  The default value to return.
   *
   *  @return True, if the property "key" was set to "true", "on", or "yes".
   *
   *  @since 2.0.11
   */
  public static boolean getBooleanProperty( Properties props,
                                            String key,
                                            boolean defval )
  {
      String val = props.getProperty( key );

      if( val == null ) return defval;

      return isPositive( val );
  }

  /**
   *  Fetches a String property from the set of Properties.  This differs from
   *  Properties.getProperty() in a couple of key respects: First, property value
   *  is trim()med (so no extra whitespace back and front), and well, that's it.
   *
   *  @param props The Properties to search through
   *  @param key   The property key
   *  @param defval A default value to return, if the property does not exist.
   *  @return The property value.
   *  @since 2.1.151
   */
  public static String getStringProperty( Properties props,
                                          String key,
                                          String defval )
  {
      String val = props.getProperty( key );

      if( val == null ) return defval;

      return val.trim();
  }

  /**
   *  Returns true, if the string "val" denotes a positive string.  Allowed
   *  values are "yes", "on", and "true".  Comparison is case-insignificant.
   *  Null values are safe.
   *
   *  @param val Value to check.
   *  @return True, if val is "true", "on", or "yes"; otherwise false.
   *
   *  @since 2.0.26
   */
  public static boolean isPositive( String val )
  {
      if( val == null ) return false;

      val = val.trim();

      return val.equalsIgnoreCase("true") || val.equalsIgnoreCase("on") ||
               val.equalsIgnoreCase("yes");
  }


  /**
   *  Parses an integer parameter, returning a default value
   *  if the value is null or a non-number.
   *  
   *  @param value The value to parse
   *  @param defvalue A default value in case the value is not a number
   *  @return The parsed value (or defvalue).
   */

  public static int parseIntParameter( String value, int defvalue )
  {
      int val = defvalue;

      try
      {
          val = Integer.parseInt( value.trim() );
      }
      catch( Exception e ) {}

      return val;
  }

}