com.mysql.cj.jdbc.ha

Class MultiHostConnectionProxy

java.lang.Object

com.mysql.cj.jdbc.ha.MultiHostConnectionProxy

All Implemented Interfaces:

java.lang.reflect.InvocationHandler

Direct Known Subclasses:

FailoverConnectionProxy, LoadBalancedConnectionProxy, ReplicationConnectionProxy

public abstract class MultiHostConnectionProxy
extends java.lang.Object
implements java.lang.reflect.InvocationHandler

An abstract class that processes generic multi-host configurations. This class has to be sub-classed by specific multi-host implementations, such as load-balancing and failover.

Field Summary

Fields

Modifier and Type	Field and Description
protected ConnectionUrl	connectionUrl
protected java.lang.Throwable	lastExceptionDealtWith

Method Summary

Modifier and Type	Method and Description
protected boolean	allowedOnClosedConnection(java.lang.reflect.Method method) Checks if the given method is allowed on closed connections.
protected JdbcConnection	getParentProxy() Get this connection's parent proxy.
protected JdbcConnection	getProxy() Get this connection's proxy.
java.lang.Object	invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args) Proxies method invocation on the java.sql.Connection interface, trapping multi-host specific methods and generic methods.
protected void	propagateProxyDown(JdbcConnection proxyConn) Propagates the connection proxy down through the multi-host connections chain.
protected void	setProxy(JdbcConnection proxyConn) Sets this connection's proxy.

Methods inherited from class java.lang.Object

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

Field Detail

connectionUrl

protected ConnectionUrl connectionUrl

lastExceptionDealtWith

protected java.lang.Throwable lastExceptionDealtWith

Method Detail

getProxy

protected JdbcConnection getProxy()

Get this connection's proxy. A multi-host connection may not be at top level in the multi-host connections chain. In such case the first connection in the chain is available as a proxy.

Returns:

Returns this connection's proxy if there is one or itself if this is the first one.

getParentProxy

protected JdbcConnection getParentProxy()

Get this connection's parent proxy.

Returns:

Returns this connection's proxy if there is one.

setProxy

protected final void setProxy(JdbcConnection proxyConn)

Sets this connection's proxy. This proxy should be the first connection in the multi-host connections chain. After setting the connection proxy locally, propagates it through the dependent connections.

Parameters:

proxyConn - The top level connection in the multi-host connections chain.

propagateProxyDown

protected void propagateProxyDown(JdbcConnection proxyConn)

Propagates the connection proxy down through the multi-host connections chain. This method is intended to be overridden in subclasses that manage more than one active connection at same time.

Parameters:

proxyConn - The top level connection in the multi-host connections chain.

invoke

public java.lang.Object invoke(java.lang.Object proxy,
                               java.lang.reflect.Method method,
                               java.lang.Object[] args)
                        throws java.lang.Throwable

Proxies method invocation on the java.sql.Connection interface, trapping multi-host specific methods and generic methods. Subclasses have to override this to complete the method invocation process, deal with exceptions and decide when to switch connection. To avoid unnecessary additional exception handling overriders should consult #canDealWith(Method) before chaining here.

Specified by:

invoke in interface java.lang.reflect.InvocationHandler

Parameters:

proxy - proxy object

method - method to invoke

args - method parameters

Returns:

method result

Throws:

java.lang.Throwable - if an error occurs

allowedOnClosedConnection

protected boolean allowedOnClosedConnection(java.lang.reflect.Method method)

Checks if the given method is allowed on closed connections.

Parameters:

method - method

Returns:

true if the given method is allowed on closed connections