Properties are used to determine various aspects of the current build environment. They do not depend on the current build configuration, but only depend on the environment of the executing computer.
Task implementations can use these classes to depend on various aspects of the build environment. If any of the dependent properties changes, the task will be rerun with appropriate deltas.
It is assumed that environment properties stay the same between consecutive build executions.
It is strongly recommended that implementations and the calculated property values implement the Externalizable interface.
Good examples for environment properties:
- Current Java Runtime version.
- Version of the used compiler for a given language.
- Underlying operating system type.
- Environment user parameters.
Bad examples for environment properties:
- Current working directory.
- Execution user parameters.
For these kind of properties, ExecutionProperty should be used.
Indicates whether some other object is "equal to" this one.
equals method implements an equivalence relation on non-null object references:
- It is reflexive: for any non-null reference value
- It is symmetric: for any non-null reference values
trueif and only if
- It is transitive: for any non-null reference values
- It is consistent: for any non-null reference values
y, multiple invocations of
trueor consistently return
false, provided no information used in
equalscomparisons on the objects is modified.
- For any non-null reference value
equals method for class
Object implements the most discriminating possible equivalence
relation on objects; that is, for any non-null reference values
y, this method returns
true if and only if
y refer to the same object (
x == y has the value
Note that it is generally necessary to override the
hashCode method whenever this method is overridden,
so as to maintain the general contract for the
hashCode method, which states that equal objects must have
equal hash codes.
true if this object is the same as the obj argument;
It is strongly recommended for the returned value to implement equals(
The general contract of
- Whenever it is invoked on the same object more than once during an execution of a Java application, the
hashCodemethod must consistently return the same integer, provided no information used in
equalscomparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
- If two objects are equal according to the
equals(Object)method, then calling the
hashCodemethod on each of the two objects must produce the same integer result.
- It is not required that if two objects are unequal according to the
Object)method, then calling the
hashCodemethod on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by class
Object does return distinct
integers for distinct objects. (This is typically implemented by converting the internal address of the object
into an integer, but this implementation technique is not required by the Java™ programming language.)