uk.ac.sheffield.vtts.client.pojo

Class Dvd

java.lang.Object

uk.ac.sheffield.vtts.client.pojo.Dvd

public class Dvd
extends java.lang.Object

Dvd is an example witness-type, implementing the symbolic type used in the ShoppingCart.xml specification. The specification language supports the built-in basic types: Void, Byte, Boolean, Character, Integer, Short, Long, Float, Double and String; and the complex types List[T], Set[T], Map[K,V] and Pair[K,V]. If a specification declares variables of any other type, this is treated as a symbolic type, but it is uninterpreted, in the sense that nothing is known about its structure. It is possible to associate other values with such symbolic types through the use of Maps in the expression language. The only necessary feature of symbolic types is that instances must be able to be distinguished. This is achieved using an ID, which by convention is the first three letters of the type-name, in lower case, followed by an incrementing digit, starting from 1.

During verification, symbolic types are modelled as instances of the model type Entity, which records the ID name and the symbolic type name. During testing, we expect these symbolic types to translate into domain-specific object types in the application, having the same type name. Testing will need to create instances of these domain types, which we refer to as witness-types, since they must provide witness-values for use during testing. Any witness-type must provide a default constructor, and a constructor that accepts a String ID value. It must also define the hashCode() method to hash on the ID value, and the equals() method to compare two ID values for equality. Apart from this, it may offer whatever methods are needed (typically, to encode internally properties expressed in the model through Maps).

The Dvd class shows how to provide such a witness-type, which requires: a default constructor that generates the first witness value; a constructor-from-String that accepts a String ID value; an equals() method that compares a pair of IDs; and a hashCode() method that hashes on the ID. The directory path to witness-types must be known to the generated test-driver. Here, we have copied Dvd to the folders client/pojo, client/rs and client/ws to make it available to generated POJO, SOAP and REST test-drivers which expect to find it there.

Version:

Broker@Cloud 1.0

Author:

Anthony J H Simons

Constructor Summary

Constructors

Constructor and Description
Dvd() The default constructor, which always creates the first Dvd in the monotonic sequence, with the identifier: "dvd1".
Dvd(java.lang.String identifier) The from-String constructor that is required for a witness-type.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(java.lang.Object other) Tests whether this Dvd and another object are equal.
int	hashCode() Returns a quasi-unique hash code for this Dvd.

Methods inherited from class java.lang.Object

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

Constructor Detail

Dvd

public Dvd()

The default constructor, which always creates the first Dvd in the monotonic sequence, with the identifier: "dvd1".

Dvd

public Dvd(java.lang.String identifier)

The from-String constructor that is required for a witness-type. By convention, the identifier for the type Dvd is expected to be the lower case character string: "dvd" followed by an incrementing digit, starting from 1.

Parameters:

identifier - a String identifier.

Method Detail

hashCode

public int hashCode()

Returns a quasi-unique hash code for this Dvd. Hashes on the value of the identifier. For safety, returns zero if the identifier is null, although this should not happen in practice.

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object other)

Tests whether this Dvd and another object are equal. If they are identical, returns true immediately. Otherwise, tests whether the other is an instance of Dvd, then compares the values of their identifiers. For safety, still works if either identifier is null, although this should not happen in practice.

Overrides:

equals in class java.lang.Object