AtomicInteger
public
class
AtomicInteger
extends Number
implements
Serializable
java.lang.Object  
↳  java.lang.Number  
↳  java.util.concurrent.atomic.AtomicInteger 
An int
value that may be updated atomically. See the
java.util.concurrent.atomic
package specification for
description of the properties of atomic variables. An
AtomicInteger
is used in applications such as atomically
incremented counters, and cannot be used as a replacement for an
Integer
. However, this class does extend
Number
to allow uniform access by tools and utilities that
deal with numericallybased classes.
Summary
Public constructors  

AtomicInteger(int initialValue)
Creates a new AtomicInteger with the given initial value. 

AtomicInteger()
Creates a new AtomicInteger with initial value 
Public methods  

final
int

accumulateAndGet(int x, IntBinaryOperator accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value. 
final
int

addAndGet(int delta)
Atomically adds the given value to the current value. 
final
boolean

compareAndSet(int expect, int update)
Atomically sets the value to the given updated value
if the current value 
final
int

decrementAndGet()
Atomically decrements by one the current value. 
double

doubleValue()
Returns the value of this 
float

floatValue()
Returns the value of this 
final
int

get()
Gets the current value. 
final
int

getAndAccumulate(int x, IntBinaryOperator accumulatorFunction)
Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value. 
final
int

getAndAdd(int delta)
Atomically adds the given value to the current value. 
final
int

getAndDecrement()
Atomically decrements by one the current value. 
final
int

getAndIncrement()
Atomically increments by one the current value. 
final
int

getAndSet(int newValue)
Atomically sets to the given value and returns the old value. 
final
int

getAndUpdate(IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the previous value. 
final
int

incrementAndGet()
Atomically increments by one the current value. 
int

intValue()
Returns the value of this 
final
void

lazySet(int newValue)
Eventually sets to the given value. 
long

longValue()
Returns the value of this 
final
void

set(int newValue)
Sets to the given value. 
String

toString()
Returns the String representation of the current value. 
final
int

updateAndGet(IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the updated value. 
final
boolean

weakCompareAndSet(int expect, int update)
Atomically sets the value to the given updated value
if the current value 
Inherited methods  

Public constructors
AtomicInteger
public AtomicInteger (int initialValue)
Creates a new AtomicInteger with the given initial value.
Parameters  

initialValue 
int : the initial value

AtomicInteger
public AtomicInteger ()
Creates a new AtomicInteger with initial value 0
.
Public methods
accumulateAndGet
public final int accumulateAndGet (int x, IntBinaryOperator accumulatorFunction)
Atomically updates 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 sideeffectfree, since it may be reapplied 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 
int : the update value 
accumulatorFunction 
IntBinaryOperator : a sideeffectfree function of two arguments 
Returns  

int 
the updated value 
addAndGet
public final int addAndGet (int delta)
Atomically adds the given value to the current value.
Parameters  

delta 
int : the value to add 
Returns  

int 
the updated value 
compareAndSet
public final boolean compareAndSet (int expect, int update)
Atomically sets the value to the given updated value
if the current value ==
the expected value.
Parameters  

expect 
int : the expected value 
update 
int : the new value 
Returns  

boolean 
true if successful. False return indicates that
the actual value was not equal to the expected value.

decrementAndGet
public final int decrementAndGet ()
Atomically decrements by one the current value.
Returns  

int 
the updated value 
doubleValue
public double doubleValue ()
Returns the value of this AtomicInteger
as a double
after a widening primitive conversion.
Returns  

double 
the numeric value represented by this object after conversion
to type double .

floatValue
public float floatValue ()
Returns the value of this AtomicInteger
as a float
after a widening primitive conversion.
Returns  

float 
the numeric value represented by this object after conversion
to type float .

get
public final int get ()
Gets the current value.
Returns  

int 
the current value 
getAndAccumulate
public final int getAndAccumulate (int x, IntBinaryOperator accumulatorFunction)
Atomically updates 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 sideeffectfree, since it may be reapplied 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 
int : the update value 
accumulatorFunction 
IntBinaryOperator : a sideeffectfree function of two arguments 
Returns  

int 
the previous value 
getAndAdd
public final int getAndAdd (int delta)
Atomically adds the given value to the current value.
Parameters  

delta 
int : the value to add 
Returns  

int 
the previous value 
getAndDecrement
public final int getAndDecrement ()
Atomically decrements by one the current value.
Returns  

int 
the previous value 
getAndIncrement
public final int getAndIncrement ()
Atomically increments by one the current value.
Returns  

int 
the previous value 
getAndSet
public final int getAndSet (int newValue)
Atomically sets to the given value and returns the old value.
Parameters  

newValue 
int : the new value 
Returns  

int 
the previous value 
getAndUpdate
public final int getAndUpdate (IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the previous value. The function should be sideeffectfree, since it may be reapplied when attempted updates fail due to contention among threads.
Parameters  

updateFunction 
IntUnaryOperator : a sideeffectfree function 
Returns  

int 
the previous value 
incrementAndGet
public final int incrementAndGet ()
Atomically increments by one the current value.
Returns  

int 
the updated value 
intValue
public int intValue ()
Returns the value of this AtomicInteger
as an int
.
Equivalent to get()
.
Returns  

int 
the numeric value represented by this object after conversion
to type int .

lazySet
public final void lazySet (int newValue)
Eventually sets to the given value.
Parameters  

newValue 
int : the new value 
longValue
public long longValue ()
Returns the value of this AtomicInteger
as a long
after a widening primitive conversion.
Returns  

long 
the numeric value represented by this object after conversion
to type long .

set
public final void set (int newValue)
Sets to the given value.
Parameters  

newValue 
int : the new value

toString
public String toString ()
Returns the String representation of the current value.
Returns  

String 
the String representation of the current value 
updateAndGet
public final int updateAndGet (IntUnaryOperator updateFunction)
Atomically updates the current value with the results of applying the given function, returning the updated value. The function should be sideeffectfree, since it may be reapplied when attempted updates fail due to contention among threads.
Parameters  

updateFunction 
IntUnaryOperator : a sideeffectfree function 
Returns  

int 
the updated value 
weakCompareAndSet
public final boolean weakCompareAndSet (int expect, int update)
Atomically sets the value to the given updated value
if the current value ==
the expected value.
May fail
spuriously and does not provide ordering guarantees, so is
only rarely an appropriate alternative to compareAndSet
.
Parameters  

expect 
int : the expected value 
update 
int : the new value 
Returns  

boolean 
true if successful
