IAtomicReference (Hazelcast Root 3.9.4 API)

All Superinterfaces:

DistributedObject

All Known Subinterfaces:

AsyncAtomicReference<E>

All Known Implementing Classes:

AtomicReferenceProxy, ClientAtomicReferenceProxy
```
public interface IAtomicReference<E>
extends DistributedObject
```
IAtomicReference is a redundant and highly available distributed alternative to the java.util.concurrent.atomic.AtomicReference. Asynchronous variants have been introduced in version 3.7. Async methods return immediately an ICompletableFuture from which the operation's result can be obtained either in a blocking manner or by registering a callback to be executed upon completion. For example:
```
     ICompletableFuture<E> future = atomicRef.getAsync();
     future.andThen(new ExecutionCallback<E>() {
          void onResponse(Long response) {
              // do something with the result
          }

          void onFailure(Throwable t) {
              // handle failure
          }
     });
 
```
In split-brain scenarios, the atomicity of the reference is lost. It is possible for different references to exist in different cluster partitions. When the split-brain heals, Hazelcast employs a largest cluster wins policy to decide which of the IAtomicReference to use. When the cluster size are equal, a random winner is chosen.
Since:

3.2

See Also:

IAtomicLong

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`alter(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it.
`E`	`alterAndGet(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it and gets the result.
`ICompletableFuture<E>`	`alterAndGetAsync(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it and gets the result.
`ICompletableFuture<Void>`	`alterAsync(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it.
`<R> R`	`apply(IFunction<E,R> function)` Applies a function on the value, the actual stored value will not change.
`<R> ICompletableFuture<R>`	`applyAsync(IFunction<E,R> function)` Applies a function on the value, the actual stored value will not change.
`void`	`clear()` Clears the current stored reference.
`ICompletableFuture<Void>`	`clearAsync()` Clears the current stored reference.
`boolean`	`compareAndSet(E expect, E update)` Atomically sets the value to the given updated value only if the current value `==` the expected value.
`ICompletableFuture<Boolean>`	`compareAndSetAsync(E expect, E update)` Atomically sets the value to the given updated value only if the current value `==` the expected value.
`boolean`	`contains(E value)` Checks if the reference contains the value.
`ICompletableFuture<Boolean>`	`containsAsync(E expected)` Checks if the reference contains the value.
`E`	`get()` Gets the current value.
`E`	`getAndAlter(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it on and gets the old value.
`ICompletableFuture<E>`	`getAndAlterAsync(IFunction<E,E> function)` Alters the currently stored reference by applying a function on it on and gets the old value.
`E`	`getAndSet(E newValue)` Gets the old value and sets the new value.
`ICompletableFuture<E>`	`getAndSetAsync(E newValue)` Gets the value and sets the new value.
`ICompletableFuture<E>`	`getAsync()` Gets the current value.
`boolean`	`isNull()` Checks if the stored reference is null.
`ICompletableFuture<Boolean>`	`isNullAsync()` Checks if the stored reference is null.
`void`	`set(E newValue)` Atomically sets the given value.
`E`	`setAndGet(E update)` Deprecated. will be removed from Hazelcast 3.4 since it doesn't really serve a purpose.
`ICompletableFuture<Void>`	`setAsync(E newValue)` Atomically sets the given value.

Methods inherited from interface com.hazelcast.core.DistributedObject
destroy, getName, getPartitionKey, getServiceName

- Method Detail
  - compareAndSet
```
boolean compareAndSet(E expect,
                      E update)
```
    Atomically sets the value to the given updated value only if the current value == the expected value.
    
    Parameters:
    
    expect - the expected value
    
    update - the new value
    
    Returns:
    
    true if successful; or false if the actual value was not equal to the expected value.
  - get
```
E get()
```
    Gets the current value.
    
    Returns:
    
    the current value
  - set
```
void set(E newValue)
```
    Atomically sets the given value.
    
    Parameters:
    
    newValue - the new value
  - getAndSet
```
E getAndSet(E newValue)
```
    Gets the old value and sets the new value.
    
    Parameters:
    
    newValue - the new value.
    
    Returns:
    
    the old value.
  - setAndGet
```
E setAndGet(E update)
```
    Deprecated. will be removed from Hazelcast 3.4 since it doesn't really serve a purpose.
    
    Sets and gets the value.
    
    Parameters:
    
    update - the new value
    
    Returns:
    
    the new value
  - isNull
```
boolean isNull()
```
    Checks if the stored reference is null.
    
    Returns:
    
    true if null, false otherwise.
  - clear
```
void clear()
```
    Clears the current stored reference.
  - contains
```
boolean contains(E value)
```
    Checks if the reference contains the value.
    
    Parameters:
    
    value - the value to check (is allowed to be null).
    
    Returns:
    
    true if the value is found, false otherwise.
  - alter
```
void alter(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it.
    
    Parameters:
    
    function - the function that alters the currently stored reference
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - alterAndGet
```
E alterAndGet(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it and gets the result.
    
    Parameters:
    
    function - the function that alters the currently stored reference
    
    Returns:
    
    the new value, the result of the applied function.
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - getAndAlter
```
E getAndAlter(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it on and gets the old value.
    
    Parameters:
    
    function - the function that alters the currently stored reference
    
    Returns:
    
    the old value, the value before the function is applied
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - apply
```
<R> R apply(IFunction<E,R> function)
```
    Applies a function on the value, the actual stored value will not change.
    
    Parameters:
    
    function - the function applied on the value, the stored value does not change
    
    Returns:
    
    the result of the function application
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - compareAndSetAsync
```
ICompletableFuture<Boolean> compareAndSetAsync(E expect,
                                               E update)
```
    Atomically sets the value to the given updated value only if the current value == the expected value.
    
    Parameters:
    
    expect - the expected value
    
    update - the new value
    
    Returns:
    
    true if successful; or false if the actual value was not equal to the expected value.
  - getAsync
```
ICompletableFuture<E> getAsync()
```
    Gets the current value.
    
    Returns:
    
    the current value
  - setAsync
```
ICompletableFuture<Void> setAsync(E newValue)
```
    Atomically sets the given value.
    
    Parameters:
    
    newValue - the new value
  - getAndSetAsync
```
ICompletableFuture<E> getAndSetAsync(E newValue)
```
    Gets the value and sets the new value.
    
    Parameters:
    
    newValue - the new value.
    
    Returns:
    
    the old value.
  - isNullAsync
```
ICompletableFuture<Boolean> isNullAsync()
```
    Checks if the stored reference is null.
    
    Returns:
    
    true if null, false otherwise.
  - clearAsync
```
ICompletableFuture<Void> clearAsync()
```
    Clears the current stored reference.
  - containsAsync
```
ICompletableFuture<Boolean> containsAsync(E expected)
```
    Checks if the reference contains the value.
    
    Parameters:
    
    expected - the value to check (is allowed to be null).
    
    Returns:
    
    true if the value is found, false otherwise.
  - alterAsync
```
ICompletableFuture<Void> alterAsync(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it.
    
    Parameters:
    
    function - the function
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - alterAndGetAsync
```
ICompletableFuture<E> alterAndGetAsync(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it and gets the result.
    
    Parameters:
    
    function - the function
    
    Returns:
    
    the new value.
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - getAndAlterAsync
```
ICompletableFuture<E> getAndAlterAsync(IFunction<E,E> function)
```
    Alters the currently stored reference by applying a function on it on and gets the old value.
    
    Parameters:
    
    function - the function
    
    Returns:
    
    the old value
    
    Throws:
    
    IllegalArgumentException - if function is null.
  - applyAsync
```
<R> ICompletableFuture<R> applyAsync(IFunction<E,R> function)
```
    Applies a function on the value, the actual stored value will not change.
    
    Parameters:
    
    function - the function
    
    Returns:
    
    the result of the function application
    
    Throws:
    
    IllegalArgumentException - if function is null.

Interface IAtomicReference<E>

Method Summary

Methods inherited from interface com.hazelcast.core.DistributedObject

Method Detail

compareAndSet

get

set

getAndSet

setAndGet

isNull

clear

contains

alter

alterAndGet

getAndAlter

apply

compareAndSetAsync

getAsync

setAsync

getAndSetAsync

isNullAsync

clearAsync

containsAsync

alterAsync

alterAndGetAsync

getAndAlterAsync

applyAsync