Package com.clickhouse.client

Class AbstractClient<T>

java.lang.Object

com.clickhouse.client.AbstractClient<T>

All Implemented Interfaces:

ClickHouseClient, AutoCloseable

public abstract class AbstractClient<T>
extends Object
implements ClickHouseClient

Base class for implementing a thread-safe ClickHouse client. It uses ReadWriteLock to manage access to underlying connection.

Field Summary

Fields

Modifier and Type	Field	Description
protected ReadWriteLock	lock

Constructor Summary

Constructors

Constructor	Description
AbstractClient()

Method Summary

Modifier and Type	Method	Description
protected boolean	checkConnection(T connection, ClickHouseNode requestServer, ClickHouseNode currentServer, ClickHouseRequest<?> request)	Checks if the underlying connection can be reused.
void	close()
protected abstract void	closeConnection(T connection, boolean force)	Closes a connection.
protected CompletableFuture<ClickHouseResponse>	failedResponse(Throwable ex)
ClickHouseConfig	getConfig()	Gets the immutable configuration associated with this client.
protected T	getConnection(ClickHouseRequest<?> request)	Gets a connection according to the given request.
protected ExecutorService	getExecutor()	Gets executor service for this client.
protected ClickHouseNode	getServer()	Gets current server.
void	init(ClickHouseConfig config)	Initializes the client using immutable configuration extracted from the builder using ClickHouseClientBuilder.getConfig().
protected abstract T	newConnection(T connection, ClickHouseNode server, ClickHouseRequest<?> request)	Creates a new connection and optionally close existing connection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.clickhouse.client.ClickHouseClient

accept, connect, execute, getOptionClass, ping

Field Detail

lock

protected final ReadWriteLock lock

Constructor Detail

AbstractClient

public AbstractClient()

Method Detail

failedResponse

protected CompletableFuture<ClickHouseResponse> failedResponse(Throwable ex)

getExecutor

protected final ExecutorService getExecutor()

Gets executor service for this client.

Returns:

executor service

Throws:

IllegalStateException - when the client is either closed or not initialized

getServer

protected final ClickHouseNode getServer()

Gets current server.

Returns:

current server

Throws:

IllegalStateException - when the client is either closed or not initialized

checkConnection

protected boolean checkConnection(T connection,
                                  ClickHouseNode requestServer,
                                  ClickHouseNode currentServer,
                                  ClickHouseRequest<?> request)

Checks if the underlying connection can be reused. In general, new connection will be created when connection is null or requestServer is different from currentServer - the existing connection will be closed in the later case.

Parameters:

connection - existing connection which may or may not be null

requestServer - non-null requested server, returned from previous call of request.getServer()

currentServer - current server, same as getServer()

request - non-null request

Returns:

true if the connection should NOT be changed(e.g. requestServer is same as currentServer); false otherwise

newConnection

protected abstract T newConnection(T connection,
                                   ClickHouseNode server,
                                   ClickHouseRequest<?> request)

Creates a new connection and optionally close existing connection. This method will be called from getConnection(ClickHouseRequest) as needed.

Parameters:

connection - existing connection which may or may not be null

server - non-null requested server, returned from previous call of request.getServer()

request - non-null request

Returns:

new connection

Throws:

CompletionException - when error occured

closeConnection

protected abstract void closeConnection(T connection,
                                        boolean force)

Closes a connection. This method will be called from close().

Parameters:

connection - connection to close

force - whether force to close the connection or not

getConnection

protected final T getConnection(ClickHouseRequest<?> request)

Gets a connection according to the given request.

Parameters:

request - non-null request

Returns:

non-null connection

Throws:

CompletionException - when error occured

getConfig

public final ClickHouseConfig getConfig()

Description copied from interface: ClickHouseClient

Gets the immutable configuration associated with this client. In most cases it's the exact same one passed to ClickHouseClient.init(ClickHouseConfig) method for initialization.

Specified by:

getConfig in interface ClickHouseClient

Returns:

configuration associated with this client

init

public void init(ClickHouseConfig config)

Description copied from interface: ClickHouseClient

Initializes the client using immutable configuration extracted from the builder using ClickHouseClientBuilder.getConfig(). In general, it's ClickHouseClientBuilder's responsiblity to call this method to initialize the client at the end of ClickHouseClientBuilder.build(). However, sometimes, you may want to call this method explicitly in order to (re)initialize the client based on certain needs. If that's the case, please consider the environment when calling this method to avoid concurrent modification, and keep in mind that 1) ClickHouseConfig is immutable but ClickHouseClient is NOT; and 2) no guarantee that this method is thread-safe.

Specified by:

init in interface ClickHouseClient

Parameters:

config - immutable configuration extracted from the builder

close

public final void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ClickHouseClient