PropertySet

Class Overview

A PropertySet is designed to be associated with other entities in the system for storing key/value property pairs.

A key can only contain one value and a key is unique across all types. If a property is set using the same key and an already existing property of the SAME type, the new value will overwrite the old. However, if a property of DIFFERENT type attempts to overwrite the existing value, a DuplicatePropertyKeyException should be thrown.

If a property is set of a type that is not allowed, a IllegalPropertyException should be thrown.

If a property is retrieved that exists but contains a value of different type, a InvalidPropertyTypeException should be thrown.

If a property is retrieved that does not exist, null (or the primitive equivalent) is returned.

If an Exception is encountered in the actual implementation of the PropertySet that needs to be rethrown, it should be wrapped in a PropertyImplementationException .

Some PropertySet implementations may not store along side the data the original type it was set as. This means that it could be retrieved using a get method of a different type without throwing an InvalidPropertyTypeException (so long as the original type can be converted to the requested type.

Typed PropertySet Example

propertySet.setString("something","99");
x = propertySet.getString("something"); // throws InvalidPropertyTypeException

Untyped PropertySet Example

propertySet.setString("something","99");
x = propertySet.getString("something"); // returns 99.

Typically (unless otherwise stated), an implementation is typed. This can be checked by calling the supportsTypes() method of the implementation.

Not all PropertySet implementations need to support setter methods (i.e. they are read only) and not all have to support storage/retrieval of specific types. The capabilities of the specific implementation can be determined by calling supportsType(int) and isSettable(String) .

Summary