- java.lang.Object
- 
- java.lang.Number
- 
- java.util.concurrent.atomic.AtomicInteger
 
 
- 
- All Implemented Interfaces:
- Serializable
 
 public class AtomicInteger extends Number implements Serializable Anintvalue that may be updated atomically. See theVarHandlespecification for descriptions of the properties of atomic accesses. AnAtomicIntegeris used in applications such as atomically incremented counters, and cannot be used as a replacement for anInteger. However, this class does extendNumberto allow uniform access by tools and utilities that deal with numerically-based classes.- Since:
- 1.5
- See Also:
- Serialized Form
 
- 
- 
Constructor SummaryConstructors Constructor Description AtomicInteger()Creates a new AtomicInteger with initial value0.AtomicInteger(int initialValue)Creates a new AtomicInteger with the given initial value.
 - 
Method SummaryAll Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description intaccumulateAndGet(int x, IntBinaryOperator accumulatorFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the updated value.intaddAndGet(int delta)Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intcompareAndExchange(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...).intcompareAndExchangeAcquire(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...).intcompareAndExchangeRelease(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...).booleancompareAndSet(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).intdecrementAndGet()Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).doubledoubleValue()Returns the current value of thisAtomicIntegeras adoubleafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).floatfloatValue()Returns the current value of thisAtomicIntegeras afloatafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).intget()Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).intgetAcquire()Returns the current value, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...).intgetAndAccumulate(int x, IntBinaryOperator accumulatorFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the previous value.intgetAndAdd(int delta)Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intgetAndDecrement()Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intgetAndIncrement()Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intgetAndSet(int newValue)Atomically sets the value tonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).intgetAndUpdate(IntUnaryOperator updateFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the previous value.intgetOpaque()Returns the current value, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...).intgetPlain()Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.intincrementAndGet()Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intintValue()Returns the current value of thisAtomicIntegeras anint, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).voidlazySet(int newValue)Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).longlongValue()Returns the current value of thisAtomicIntegeras alongafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).voidset(int newValue)Sets the value tonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).voidsetOpaque(int newValue)Sets the value tonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).voidsetPlain(int newValue)Sets the value tonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.voidsetRelease(int newValue)Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).StringtoString()Returns the String representation of the current value.intupdateAndGet(IntUnaryOperator updateFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the updated value.booleanweakCompareAndSet(int expectedValue, int newValue)Deprecated.This method has plain memory effects but the method name implies volatile memory effects (see methods such ascompareAndExchange(int, int)andcompareAndSet(int, int)).booleanweakCompareAndSetAcquire(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).booleanweakCompareAndSetPlain(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).booleanweakCompareAndSetRelease(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).booleanweakCompareAndSetVolatile(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).- 
Methods declared in class java.lang.NumberbyteValue, shortValue
 
- 
 
- 
- 
- 
Method Detail- 
getpublic final int get() Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Returns:
- the current value
 
 - 
setpublic final void set(int newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).- Parameters:
- newValue- the new value
 
 - 
lazySetpublic final void lazySet(int newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 1.6
 
 - 
getAndSetpublic final int getAndSet(int newValue) Atomically sets the value tonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).- Parameters:
- newValue- the new value
- Returns:
- the previous value
 
 - 
compareAndSetpublic final boolean compareAndSet(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful. False return indicates that the actual value was not equal to the expected value.
 
 - 
weakCompareAndSet@Deprecated(since="9") public final boolean weakCompareAndSet(int expectedValue, int newValue) Deprecated.This method has plain memory effects but the method name implies volatile memory effects (see methods such ascompareAndExchange(int, int)andcompareAndSet(int, int)). To avoid confusion over plain or volatile memory effects it is recommended that the methodweakCompareAndSetPlain(int, int)be used instead.Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- See Also:
- weakCompareAndSetPlain(int, int)
 
 - 
weakCompareAndSetPlainpublic final boolean weakCompareAndSetPlain(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 - 
getAndIncrementpublic final int getAndIncrement() Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to getAndAdd(1).- Returns:
- the previous value
 
 - 
getAndDecrementpublic final int getAndDecrement() Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to getAndAdd(-1).- Returns:
- the previous value
 
 - 
getAndAddpublic final int getAndAdd(int delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).- Parameters:
- delta- the value to add
- Returns:
- the previous value
 
 - 
incrementAndGetpublic final int incrementAndGet() Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to addAndGet(1).- Returns:
- the updated value
 
 - 
decrementAndGetpublic final int decrementAndGet() Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to addAndGet(-1).- Returns:
- the updated value
 
 - 
addAndGetpublic final int addAndGet(int delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).- Parameters:
- delta- the value to add
- Returns:
- the updated value
 
 - 
getAndUpdatepublic final int getAndUpdate(IntUnaryOperator updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.- Parameters:
- updateFunction- a side-effect-free function
- Returns:
- the previous value
- Since:
- 1.8
 
 - 
updateAndGetpublic final int updateAndGet(IntUnaryOperator updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.- Parameters:
- updateFunction- a side-effect-free function
- Returns:
- the updated value
- Since:
- 1.8
 
 - 
getAndAccumulatepublic final int getAndAccumulate(int x, IntBinaryOperator accumulatorFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.- Parameters:
- x- the update value
- accumulatorFunction- a side-effect-free function of two arguments
- Returns:
- the previous value
- Since:
- 1.8
 
 - 
accumulateAndGetpublic final int accumulateAndGet(int x, IntBinaryOperator accumulatorFunction)Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.- Parameters:
- x- the update value
- accumulatorFunction- a side-effect-free function of two arguments
- Returns:
- the updated value
- Since:
- 1.8
 
 - 
toStringpublic String toString() Returns the String representation of the current value.
 - 
intValuepublic int intValue() Returns the current value of thisAtomicIntegeras anint, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...). Equivalent toget().
 - 
longValuepublic long longValue() Returns the current value of thisAtomicIntegeras alongafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).
 - 
floatValuepublic float floatValue() Returns the current value of thisAtomicIntegeras afloatafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Specified by:
- floatValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type float.
- See The Java™ Language Specification:
- 5.1.2 Widening Primitive Conversions
 
 - 
doubleValuepublic double doubleValue() Returns the current value of thisAtomicIntegeras adoubleafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Specified by:
- doubleValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type double.
- See The Java™ Language Specification:
- 5.1.2 Widening Primitive Conversions
 
 - 
getPlainpublic final int getPlain() Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.- Returns:
- the value
- Since:
- 9
 
 - 
setPlainpublic final void setPlain(int newValue) Sets the value tonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.- Parameters:
- newValue- the new value
- Since:
- 9
 
 - 
getOpaquepublic final int getOpaque() Returns the current value, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...).- Returns:
- the value
- Since:
- 9
 
 - 
setOpaquepublic final void setOpaque(int newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 9
 
 - 
getAcquirepublic final int getAcquire() Returns the current value, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...).- Returns:
- the value
- Since:
- 9
 
 - 
setReleasepublic final void setRelease(int newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 9
 
 - 
compareAndExchangepublic final int compareAndExchange(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
 - 
compareAndExchangeAcquirepublic final int compareAndExchangeAcquire(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
 - 
compareAndExchangeReleasepublic final int compareAndExchangeRelease(int expectedValue, int newValue)Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
 - 
weakCompareAndSetVolatilepublic final boolean weakCompareAndSetVolatile(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 - 
weakCompareAndSetAcquirepublic final boolean weakCompareAndSetAcquire(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 - 
weakCompareAndSetReleasepublic final boolean weakCompareAndSetRelease(int expectedValue, int newValue)Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 
- 
 
-