jodd-core/src/main/java/jodd/util/StringUtil.java
public static String trimDown(String string) {
		string = string.trim();
		if (string.length() == 0) {
			string = null;
		}
		return string;
	}
public static String trimDown(String string) {
		string = string.trim();
		if (string.length() == 0) {
			string = null;
		}
		return string;
	}
public static String trimDown ( String string ) { string = string . trim ( ) ; if ( string . length ( ) == 0 ) { string = null ; } return string ; }
Trims string and sets to <code>null</code> if trimmed string is empty.
Trims string and sets to <code > null< / code > if trimmed string is empty .