@ConsumerType public interface Condition
In dynamic systems, such as OSGi, one of the more challenging problems can be to define when a system or part of it is ready to do work. The answer can change depending on the individual perspective. The developer of a web server might say, the system is ready when the server starts listening on port 80. An application developer however would define the system as ready when the database connection is up and all servlets are registered. Taking the application developers view, the web server should start listening on port 80 when the application is ready and not beforehand.
Condition service interface is a marker interface designed to
address this issue. Its role is to provide a dependency that can be tracked.
It acts as a defined signal to other services.
Condition service must be registered with the
CONDITION_ID service property.
|Modifier and Type||Field and Description|
Service property identifying a condition's unique identifier.
The unique identifier for the default True condition.
A condition instance that can be used to register
static final java.lang.String CONDITION_ID
Condition service can potentially describe more then one
condition, the type of this service property is
static final java.lang.String CONDITION_ID_TRUE
The default True condition is registered by the framework during framework initialization and therefore can always be relied upon.
static final Condition INSTANCE
This can be helpful to avoid a bundle having to implement this interface
to register a
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