SimpleChannelPool (Netty API Reference (4.1.115.Final))

java.lang.Object
- io.netty.channel.pool.SimpleChannelPool

All Implemented Interfaces:

ChannelPool, Closeable, AutoCloseable

Direct Known Subclasses:

FixedChannelPool
```
public class SimpleChannelPool
extends Object
implements ChannelPool
```
Simple ChannelPool implementation which will create new Channels if someone tries to acquire a Channel but none is in the pool atm. No limit on the maximal concurrent Channels is enforced. This implementation uses LIFO order for Channels in the ChannelPool.

Constructor Summary

Constructors
Constructor and Description
`SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler)` Creates a new instance using the `ChannelHealthChecker.ACTIVE`.
`SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck)` Creates a new instance.
`SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck, boolean releaseHealthCheck)` Creates a new instance.
`SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck, boolean releaseHealthCheck, boolean lastRecentUsed)` Creates a new instance.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Future<Channel>`	`acquire()` Acquire a `Channel` from this `ChannelPool`.
`Future<Channel>`	`acquire(Promise<Channel> promise)` Acquire a `Channel` from this `ChannelPool`.
`protected Bootstrap`	`bootstrap()` Returns the `Bootstrap` this pool will use to open new connections.
`void`	`close()`
`Future<Void>`	`closeAsync()` Closes the pool in an async manner.
`protected ChannelFuture`	`connectChannel(Bootstrap bs)` Bootstrap a new `Channel`.
`protected ChannelPoolHandler`	`handler()` Returns the `ChannelPoolHandler` that will be notified for the different pool actions.
`protected ChannelHealthChecker`	`healthChecker()` Returns the `ChannelHealthChecker` that will be used to check if a `Channel` is healthy.
`protected boolean`	`offerChannel(Channel channel)` Offer a `Channel` back to the internal storage.
`protected Channel`	`pollChannel()` Poll a `Channel` out of the internal storage to reuse it.
`Future<Void>`	`release(Channel channel)` Release a `Channel` back to this `ChannelPool`.
`Future<Void>`	`release(Channel channel, Promise<Void> promise)` Release a `Channel` back to this `ChannelPool`.
`protected boolean`	`releaseHealthCheck()` Indicates whether this pool will check the health of channels before offering them back into the pool.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - SimpleChannelPool
```
public SimpleChannelPool(Bootstrap bootstrap,
                         ChannelPoolHandler handler)
```
    Creates a new instance using the ChannelHealthChecker.ACTIVE.
    
    Parameters:
    
    bootstrap - the Bootstrap that is used for connections
    
    handler - the ChannelPoolHandler that will be notified for the different pool actions
  - SimpleChannelPool
```
public SimpleChannelPool(Bootstrap bootstrap,
                         ChannelPoolHandler handler,
                         ChannelHealthChecker healthCheck)
```
    Creates a new instance.
    
    Parameters:
    
    bootstrap - the Bootstrap that is used for connections
    
    handler - the ChannelPoolHandler that will be notified for the different pool actions
    
    healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool
  - SimpleChannelPool
```
public SimpleChannelPool(Bootstrap bootstrap,
                         ChannelPoolHandler handler,
                         ChannelHealthChecker healthCheck,
                         boolean releaseHealthCheck)
```
    Creates a new instance.
    
    Parameters:
    
    bootstrap - the Bootstrap that is used for connections
    
    handler - the ChannelPoolHandler that will be notified for the different pool actions
    
    healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool
    
    releaseHealthCheck - will check channel health before offering back if this parameter set to true; otherwise, channel health is only checked at acquisition time
  - SimpleChannelPool
```
public SimpleChannelPool(Bootstrap bootstrap,
                         ChannelPoolHandler handler,
                         ChannelHealthChecker healthCheck,
                         boolean releaseHealthCheck,
                         boolean lastRecentUsed)
```
    Creates a new instance.
    
    Parameters:
    
    bootstrap - the Bootstrap that is used for connections
    
    handler - the ChannelPoolHandler that will be notified for the different pool actions
    
    healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool
    
    releaseHealthCheck - will check channel health before offering back if this parameter set to true; otherwise, channel health is only checked at acquisition time
    
    lastRecentUsed - true Channel selection will be LIFO, if false FIFO.
- Method Detail
  - bootstrap
```
protected Bootstrap bootstrap()
```
    Returns the Bootstrap this pool will use to open new connections.
    
    Returns:
    
    the Bootstrap this pool will use to open new connections
  - handler
```
protected ChannelPoolHandler handler()
```
    Returns the ChannelPoolHandler that will be notified for the different pool actions.
    
    Returns:
    
    the ChannelPoolHandler that will be notified for the different pool actions
  - healthChecker
```
protected ChannelHealthChecker healthChecker()
```
    Returns the ChannelHealthChecker that will be used to check if a Channel is healthy.
    
    Returns:
    
    the ChannelHealthChecker that will be used to check if a Channel is healthy
  - releaseHealthCheck
```
protected boolean releaseHealthCheck()
```
    Indicates whether this pool will check the health of channels before offering them back into the pool.
    
    Returns:
    
    true if this pool will check the health of channels before offering them back into the pool, or false if channel health is only checked at acquisition time
  - acquire
```
public final Future<Channel> acquire()
```
    Description copied from interface: ChannelPool
    
    Acquire a Channel from this ChannelPool. The returned Future is notified once the acquire is successful and failed otherwise. Its important that an acquired is always released to the pool again, even if the Channel is explicitly closed..
    
    Specified by:
    
    acquire in interface ChannelPool
  - acquire
```
public Future<Channel> acquire(Promise<Channel> promise)
```
    Description copied from interface: ChannelPool
    
    Acquire a Channel from this ChannelPool. The given Promise is notified once the acquire is successful and failed otherwise. Its important that an acquired is always released to the pool again, even if the Channel is explicitly closed..
    
    Specified by:
    
    acquire in interface ChannelPool
  - connectChannel
```
protected ChannelFuture connectChannel(Bootstrap bs)
```
    Bootstrap a new Channel. The default implementation uses Bootstrap.connect(), sub-classes may override this.
    The Bootstrap that is passed in here is cloned via Bootstrap.clone(), so it is safe to modify.
  - release
```
public final Future<Void> release(Channel channel)
```
    Description copied from interface: ChannelPool
    
    Release a Channel back to this ChannelPool. The returned Future is notified once the release is successful and failed otherwise. When failed the Channel will automatically closed.
    
    Specified by:
    
    release in interface ChannelPool
  - release
```
public Future<Void> release(Channel channel,
                            Promise<Void> promise)
```
    Description copied from interface: ChannelPool
    
    Release a Channel back to this ChannelPool. The given Promise is notified once the release is successful and failed otherwise. When failed the Channel will automatically closed.
    
    Specified by:
    
    release in interface ChannelPool
  - pollChannel
```
protected Channel pollChannel()
```
    Poll a Channel out of the internal storage to reuse it. This will return null if no Channel is ready to be reused. Sub-classes may override pollChannel() and offerChannel(Channel). Be aware that implementations of these methods needs to be thread-safe!
  - offerChannel
```
protected boolean offerChannel(Channel channel)
```
    Offer a Channel back to the internal storage. This will return true if the Channel could be added, false otherwise. Sub-classes may override pollChannel() and offerChannel(Channel). Be aware that implementations of these methods needs to be thread-safe!
  - close
```
public void close()
```
    Specified by:
    
    close in interface ChannelPool
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
  - closeAsync
```
public Future<Void> closeAsync()
```
    Closes the pool in an async manner.
    
    Returns:
    
    Future which represents completion of the close task

Class SimpleChannelPool

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SimpleChannelPool

SimpleChannelPool

SimpleChannelPool

SimpleChannelPool

Method Detail

bootstrap

handler

healthChecker

releaseHealthCheck

acquire

acquire

connectChannel

release

release

pollChannel

offerChannel

close

closeAsync