Package org.jmock.expectation

Class Null

  • public class Null
extends java.lang.Object
    A class that represents the null value. The Null class is used when an Expectation is set to expect nothing.

    Example usage: 

     public class MockX {
    private Expectation... anExpectation = new Expectation...(...);
 
    
    public MockX() {
       anExpectation.setExpectNothing();
    }
 
    
    public void setAnExpectation(Object value) {
       anExpectation.setExpected(value);
    }
 
    
    public void setActual(Object value) {
       anExpectation.setActual(value);
    }
 }
    The act of calling Expectation.setExpectNothing() tells the expectation that it should expect no values to change. Since all Null objects are equal to themselves, most expectations set their expected value to an instance of Null, and at the same time, set their actual value to another instance of Null. This way, when org.jmock.expectation.Verifiable#verify() checks expectations, they will compare two Null objects together, which is guaranteed to succeed.
    Version:
    $Id$
    Author:
    Francois Beausoleil (fbos@users.sourceforge.net)

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String DEFAULT_DESCRIPTION
      The default description for all Null objects.
      static Null NULL
      A default Null object.

    • Constructor Summary

      Constructors 
      Constructor Description
      Null()
      Instantiates a new Null object with the default description.
      Null​(java.lang.String description)
      Instantiates a new Null object and sets it's description.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object other)
      Determines equality between two objects.
      int hashCode()
      Returns this Null object's hashCode.
      java.lang.String toString()
      Returns a string representation of this Null object.

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    • Field Detail

      • DEFAULT_DESCRIPTION

        public static final java.lang.String DEFAULT_DESCRIPTION
        The default description for all Null objects. This String is equal to "Null".
        See Also:
        Constant Field Values

      • NULL

        public static final Null NULL
        A default Null object. Instead of always instantiating new Null objects, consider using a reference to this object instead. This way, the virtual machine will not be taking the time required to instantiate an object everytime it is required.

    • Constructor Detail

      • Null

        public Null​(java.lang.String description)
        Instantiates a new Null object and sets it's description.
        Parameters:
        description -

    • Method Detail

      • equals

        public boolean equals​(java.lang.Object other)
        Determines equality between two objects. Null objects are only equal to another instance of themselves.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        other -

      • hashCode

        public int hashCode()
        Returns this Null object's hashCode. All Null return the same hashCode value.
        Overrides:
        hashCode in class java.lang.Object

      • toString

        public java.lang.String toString()
        Returns a string representation of this Null object. This merely returns the string passed to the constructor initially.
        Overrides:
        toString in class java.lang.Object