Package org.springframework.util
Class ConcurrencyThrottleSupport
- java.lang.Object
- org.springframework.util.ConcurrencyThrottleSupport
- All Implemented Interfaces:
Serializable
- Direct Known Subclasses:
ConcurrencyThrottleInterceptor
public abstract class ConcurrencyThrottleSupport extends Object implements Serializable
Support class for throttling concurrent access to a specific resource.Designed for use as a base class, with the subclass invoking the
beforeAccess()andafterAccess()methods at appropriate points of its workflow. Note thatafterAccessshould usually be called in a finally block!The default concurrency limit of this support class is -1 ("unbounded concurrency"). Subclasses may override this default; check the javadoc of the concrete class that you're using.
- Since:
- 1.2.5
- Author:
- Juergen Hoeller
- See Also:
setConcurrencyLimit(int),beforeAccess(),afterAccess(),ConcurrencyThrottleInterceptor,Serializable, Serialized Form
Field Summary
Fields Modifier and Type Field Description protected LogloggerTransient to optimize serializationstatic intNO_CONCURRENCYSwitch concurrency 'off': that is, don't allow any concurrent invocations.static intUNBOUNDED_CONCURRENCYPermit any number of concurrent invocations: that is, don't throttle concurrency.
Constructor Summary
Constructors Constructor Description ConcurrencyThrottleSupport()
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected voidafterAccess()To be invoked after the main execution logic of concrete subclasses.protected voidbeforeAccess()To be invoked before the main execution logic of concrete subclasses.intgetConcurrencyLimit()Return the maximum number of concurrent access attempts allowed.booleanisThrottleActive()Return whether this throttle is currently active.voidsetConcurrencyLimit(int concurrencyLimit)Set the maximum number of concurrent access attempts allowed.
Field Detail
UNBOUNDED_CONCURRENCY
public static final int UNBOUNDED_CONCURRENCY
Permit any number of concurrent invocations: that is, don't throttle concurrency.- See Also:
- Constant Field Values
NO_CONCURRENCY
public static final int NO_CONCURRENCY
Switch concurrency 'off': that is, don't allow any concurrent invocations.- See Also:
- Constant Field Values
Constructor Detail
ConcurrencyThrottleSupport
public ConcurrencyThrottleSupport()
Method Detail
setConcurrencyLimit
public void setConcurrencyLimit(int concurrencyLimit)
Set the maximum number of concurrent access attempts allowed. -1 indicates unbounded concurrency.In principle, this limit can be changed at runtime, although it is generally designed as a config time setting.
NOTE: Do not switch between -1 and any concrete limit at runtime, as this will lead to inconsistent concurrency counts: A limit of -1 effectively turns off concurrency counting completely.
getConcurrencyLimit
public int getConcurrencyLimit()
Return the maximum number of concurrent access attempts allowed.
isThrottleActive
public boolean isThrottleActive()
Return whether this throttle is currently active.- Returns:
trueif the concurrency limit for this instance is active- See Also:
getConcurrencyLimit()
beforeAccess
protected void beforeAccess()
To be invoked before the main execution logic of concrete subclasses.This implementation applies the concurrency throttle.
- See Also:
afterAccess()
afterAccess
protected void afterAccess()
To be invoked after the main execution logic of concrete subclasses.- See Also:
beforeAccess()