Wrapper classes: The Java's primitive types are not of object types. The wrapper classes are stated in the java.lang package. They comprises of a class for each and every primitive type: Boolean, Byte, Double, Float, Integer, Long & Short and Character. Such classes give methods to parse strings having primitive values, and turn primitive values into the strings. The Double and Float classes as well provide methods to detect special bit patterns for the floating point numbers, symbolizing values like NaN, +infinity and -infinity.