com.pushtechnology.diffusion.client.features

Interface UpdateConstraint.Factory

Enclosing interface:

UpdateConstraint

public static interface UpdateConstraint.Factory

Factory for the constraint types.

An instance can be obtained by calling Diffusion.updateConstraints().

Method Summary

Modifier and Type	Method and Description
UpdateConstraint.PartialJSON	jsonValue() Create a constraint that partially matches the current topic value.
UpdateConstraint	locked(Session.SessionLock lock) Create a constraint requiring a lock to be held by the session.
UpdateConstraint	noTopic() Create a constraint requiring the path to have no topic.
UpdateConstraint	noValue() Create a constraint requiring the topic to have no value.
default UpdateConstraint	value(Object value) Create a constraint requiring the current value of a topic to exactly match the supplied value.
UpdateConstraint	value(UpdateConstraint.Operator operator, Object value) Create a constraint comparing the current value of a topic to a supplied value.

Method Detail

locked

UpdateConstraint locked(Session.SessionLock lock)

Create a constraint requiring a lock to be held by the session.

This can be used to coordinate operations between multiple sessions.

Parameters:

lock - the lock

Returns:

the constraint

value

default UpdateConstraint value(Object value)
                        throws IllegalArgumentException

Create a constraint requiring the current value of a topic to exactly match the supplied value.

This is exactly equivalent to calling value(UpdateConstraint.Operator, Object) specifying the IS operator.

Parameters:

value - the value

Returns:

the constraint

Throws:

IllegalArgumentException - if the value type is not supported

value

UpdateConstraint value(UpdateConstraint.Operator operator,
                       Object value)

Create a constraint comparing the current value of a topic to a supplied value.

If a String value is supplied and the operator is EQ or NE, the string representation of the topic will be compared to the supplied value. This can only be used with primitive topic types (or TIME_SERIES topics with a primitive event type). Other operators (other than IS) are not permitted with String values.

If a number value is supplied (Integer, Long or Double) the value will be compared with the number value of the topic. This will work with STRING, INT64 or DOUBLE topics (or TIME_SERIES topics with a primitive event type) only. STRING topics can only be compared if they contain a value that can be parsed as a number. If the value of a STRING topic cannot be parsed as a number, or the topic is of any other non-number type the constraint will be unsatisfied. Any of the operators (other than IS) can be used with such number comparisons. Decimal numbers can be compared with integral numbers so 1 is equal to 1.0, "1", or "1.0".

If the IS operator is specified the specified value will be compared to the topic value for strict binary equality. The value type can be any value type supported by DataTypes (Integer is allowed and is treated as a Long) or any Bytes value and can be used to compare against any topic type.

When a STRING, INT64 or DOUBLE topic is updated to a null value, the topic is set to have no value. Use the noValue() constraint to check if the topic has no value.

This constraint is unsatisfied if no topic is present at the path.

Parameters:

operator - the operator that determines the type of comparison

value - the value

Returns:

the constraint

Throws:

IllegalArgumentException - if the the operator is not compatible with the value type or the value type is not supported

Since:

6.10

noValue

UpdateConstraint noValue()

Create a constraint requiring the topic to have no value.

This constraint is unsatisfied if no topic is present at the path.

Returns:

the constraint

noTopic

UpdateConstraint noTopic()

Create a constraint requiring the path to have no topic.

This is useful when setting the first value of a topic being added using addAndSet without changing the value if the topic already exists. This constraint is unsatisfied if a topic is present at the path.

Returns:

the constraint

jsonValue

UpdateConstraint.PartialJSON jsonValue()

Create a constraint that partially matches the current topic value.

The topic must be a JSON topic (or a TIME_SERIES topic with a json event type). The UpdateConstraint.PartialJSON partially describes the structure of a JSON value. The with or without methods must be used to fully qualify the constraint.

The constraint is unsatisfied if no topic is present at the path.

Returns:

the constraint