public static String extractPropertyValue(String propertyName,
    Properties properties) 
{
		String value = properties.getProperty( propertyName );
		if ( value == null ) {
			return null;
		}
		value = value.trim();
		if ( StringHelper.isEmpty( value ) ) {
			return null;
		}
		return value;
}

Extract a property value by name from the given properties object.

Both null and empty string are viewed as the same, and return null.

 public static boolean getBoolean(String propertyName,
    Properties properties) 
{
		return getBoolean( propertyName, properties, false );
}

Get a property value as a boolean. Shorthand for calling #getBoolean(String, java.util.Properties, boolean) with false as the default value.

 public static boolean getBoolean(String propertyName,
    Properties properties,
    boolean defaultValue) 
{
		String value = extractPropertyValue( propertyName, properties );
		return value == null ? defaultValue : Boolean.valueOf( value ).booleanValue();
}

Get a property value as a boolean.

First, the string value is extracted, and then Boolean#valueOf(String) is used to determine the correct boolean value.

 public static int getInt(String propertyName,
    Properties properties,
    int defaultValue) 
{
		String value = extractPropertyValue( propertyName, properties );
		return value == null ? defaultValue : Integer.parseInt( value );
}

Get a property value as an int.

First, the string value is extracted, and then Integer#parseInt(String) is used to determine the correct int value for any non-null property values.

 public static Integer getInteger(String propertyName,
    Properties properties) 
{
		String value = extractPropertyValue( propertyName, properties );
		return value == null ? null : Integer.valueOf( value );
}

Get a property value as an Integer.

First, the string value is extracted, and then Integer#valueOf(String) is used to determine the correct boolean value for any non-null property values.

 public static String getString(String propertyName,
    Properties properties,
    String defaultValue) 
{
		String value = extractPropertyValue( propertyName, properties );
		return value == null ? defaultValue : value;
}

Get a property value as a string.

 public static Properties maskOut(Properties props,
    String key) 
{
		Properties clone = ( Properties ) props.clone();
		if ( clone.get( key ) != null ) {
			clone.setProperty( key, "****" );
		}
		return clone;
}

replace a property by a starred version

 public static String resolvePlaceHolder(String property) 
{
		if ( property.indexOf( PLACEHOLDER_START ) <  0 ) {
			return property;
		}
		StringBuffer buff = new StringBuffer();
		char[] chars = property.toCharArray();
		for ( int pos = 0; pos <  chars.length; pos++ ) {
			if ( chars[pos] == '$" ) {
				// peek ahead
				if ( chars[pos+1] == '{" ) {
					// we have a placeholder, spin forward till we find the end
					String systemPropertyName = "";
					int x = pos + 2;
					for (  ; x <  chars.length && chars[x] != '}"; x++ ) {
						systemPropertyName += chars[x];
						// if we reach the end of the string w/o finding the
						// matching end, that is an exception
						if ( x == chars.length - 1 ) {
							throw new IllegalArgumentException( "unmatched placeholder start [" + property + "]" );
						}
					}
					String systemProperty = extractFromSystem( systemPropertyName );
					buff.append( systemProperty == null ? "" : systemProperty );
					pos = x + 1;
					// make sure spinning forward did not put us past the end of the buffer...
					if ( pos  >= chars.length ) {
						break;
					}
				}
			}
			buff.append( chars[pos] );
		}
		String rtn = buff.toString();
		return StringHelper.isEmpty( rtn ) ? null : rtn;
}

Handles interpolation processing for a single property.

 public static  void resolvePlaceHolders(Properties properties) 
{
		Iterator itr = properties.entrySet().iterator();
		while ( itr.hasNext() ) {
			final Map.Entry entry = ( Map.Entry ) itr.next();
			final Object value = entry.getValue();
			if ( value != null && String.class.isInstance( value ) ) {
				final String resolved = resolvePlaceHolder( ( String ) value );
				if ( !value.equals( resolved ) ) {
					if ( resolved == null ) {
						itr.remove();
					}
					else {
						entry.setValue( resolved );
					}
				}
			}
		}
}

Handles interpolation processing for all entries in a properties object.

 public static Map toMap(String propertyName,
    String delim,
    Properties properties) 
{
		Map map = new HashMap();
		String value = extractPropertyValue( propertyName, properties );
		if ( value != null ) {
			StringTokenizer tokens = new StringTokenizer( value, delim );
			while ( tokens.hasMoreTokens() ) {
				map.put( tokens.nextToken(), tokens.hasMoreElements() ? tokens.nextToken() : "" );
			}
		}
		return map;
}

Constructs a map from a property value.

The exact behavior here is largely dependant upon what is passed in as the delimiter.

 public static String[] toStringArray(String stringForm,
    String delim) 
{
		// todo : move to StringHelper?
		if ( stringForm != null ) {
			return StringHelper.split( delim, stringForm );
		}
		else {
			return ArrayHelper.EMPTY_STRING_ARRAY;
		}
}

Convert a string to an array of strings. The assumption is that the individual array elements are delimited in the source stringForm param by the delim param.

 public static String[] toStringArray(String propertyName,
    String delim,
    Properties properties) 
{
		return toStringArray( extractPropertyValue( propertyName, properties ), delim );
}

Get a property value as a string array.