Ambiguous mapping method but there is a more specific mapping

I have a util class that has the following methods:

public static java.util.Date toUtilDate(String strDate);
public static java.sql.TimeStamp toTimeStamp(String strDate);
public static java.sql.TimeStamp toTimeStamp2(String strDate);
public static java.sql.Date toSqlDate(String strDate);

I want to map from String to java.util.Date. I am getting an Ambiguous mapping error. I think that if an explicit mapping between String to java.util.Date exists then we should select that method. If the toUtilDate method didn't exists then we should throw the error.

WDYT?