java.lang

Class NullPointerException

  • All Implemented Interfaces:
    Serializable 

    public class NullPointerException
extends RuntimeException
    Thrown when an application attempts to use null in a case where an object is required. These include:
    • Calling the instance method of a null object.
    • Accessing or modifying the field of a null object.
    • Taking the length of null as if it were an array.
    • Accessing or modifying the slots of null as if it were an array.
    • Throwing null as if it were a Throwable value.

    Applications should throw instances of this class to indicate other illegal uses of the null object. NullPointerException objects may be constructed by the virtual machine as if suppression were disabled and/or the stack trace was not writable.

    Since:
    JDK1.0
    See Also:
    Serialized Form

    • Constructor Detail

      • NullPointerException

        public NullPointerException()
        Constructs a NullPointerException with no detail message.

      • NullPointerException

        public NullPointerException(String s)
        Constructs a NullPointerException with the specified detail message.
        Parameters:
        s - the detail message.