MultiHostConnectionProxy (aws-mysql-jdbc 0.3.0 API)

java.lang.Object
- com.mysql.cj.jdbc.ha.MultiHostConnectionProxy

All Implemented Interfaces:

java.lang.reflect.InvocationHandler

Direct Known Subclasses:

ClusterAwareConnectionProxy, 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 boolean`	`autoReconnect`
`protected boolean`	`closedExplicitly`
`protected java.lang.String`	`closedReason`
`protected ConnectionUrl`	`connectionUrl`
`protected JdbcConnection`	`currentConnection`
`protected java.util.List<HostInfo>`	`hostsList`
`protected boolean`	`isClosed`
`protected java.lang.Throwable`	`lastExceptionDealtWith`
`protected JdbcConnection`	`thisAsConnection`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`MultiHostConnectionProxy(ConnectionUrl connectionUrl)` Constructs a MultiHostConnectionProxy instance for the given connection URL.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
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 ConnectionImpl`	`createConnectionForHost(HostInfo hostInfo)` Creates a new physical connection for the given `HostInfo`.
`protected void`	`dealWithInvocationException(java.lang.reflect.InvocationTargetException e)` Deals with InvocationException from proxied objects.
`protected abstract void`	`doAbort(java.util.concurrent.Executor executor)` Executes a abort() invocation;
`protected abstract void`	`doAbortInternal()` Executes a abortInternal() invocation;
`protected abstract void`	`doClose()` Executes a close() invocation;
`protected java.lang.reflect.InvocationHandler`	`getNewJdbcInterfaceProxy(java.lang.Object toProxy)` Instantiates a new JdbcInterfaceProxy for the given object.
`protected JdbcConnection`	`getParentProxy()` Get this connection's parent proxy.
`protected JdbcConnection`	`getProxy()` Get this connection's proxy.
`protected void`	`invalidateConnection(JdbcConnection conn)` Invalidates the specified connection by closing it.
`protected void`	`invalidateCurrentConnection()` Invalidates the current connection.
`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 abstract java.lang.Object`	`invokeMore(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)` Continuation of the method invocation process, to be implemented within each subclass.
`protected abstract boolean`	`isSourceConnection()` Checks if current connection is to a source host.
`protected abstract void`	`pickNewConnection()` Picks the "best" connection to use from now on.
`protected void`	`propagateProxyDown(JdbcConnection proxyConn)` Propagates the connection proxy down through the multi-host connections chain.
`protected java.lang.Object`	`proxyIfReturnTypeIsJdbcInterface(java.lang.Class<?> returnType, java.lang.Object toProxy)` If the given return type is or implements a JDBC interface, proxies the given object so that we can catch SQL errors and fire a connection switch.
`protected void`	`setProxy(JdbcConnection proxyConn)` Sets this connection's proxy.
`protected abstract boolean`	`shouldExceptionTriggerConnectionSwitch(java.lang.Throwable t)` Checks if the given throwable should trigger a connection switch.
`protected void`	`syncSessionState(JdbcConnection source, JdbcConnection target, boolean readOnly)` Synchronizes session state between two connections, allowing to override the read-only status.

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

- Field Detail
  - hostsList
```
protected java.util.List<HostInfo> hostsList
```
  - connectionUrl
```
protected ConnectionUrl connectionUrl
```
  - autoReconnect
```
protected boolean autoReconnect
```
  - thisAsConnection
```
protected JdbcConnection thisAsConnection
```
  - currentConnection
```
protected JdbcConnection currentConnection
```
  - isClosed
```
protected boolean isClosed
```
  - closedExplicitly
```
protected boolean closedExplicitly
```
  - closedReason
```
protected java.lang.String closedReason
```
  - lastExceptionDealtWith
```
protected java.lang.Throwable lastExceptionDealtWith
```
- Constructor Detail
  - MultiHostConnectionProxy
```
protected MultiHostConnectionProxy(ConnectionUrl connectionUrl)
                            throws java.sql.SQLException
```
    Constructs a MultiHostConnectionProxy instance for the given connection URL.
    
    Parameters:
    
    connectionUrl - The connection URL.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
- 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.
  - proxyIfReturnTypeIsJdbcInterface
```
protected java.lang.Object proxyIfReturnTypeIsJdbcInterface(java.lang.Class<?> returnType,
                                                            java.lang.Object toProxy)
```
    If the given return type is or implements a JDBC interface, proxies the given object so that we can catch SQL errors and fire a connection switch.
    
    Parameters:
    
    returnType - The type the object instance to proxy is supposed to be.
    
    toProxy - The object instance to proxy.
    
    Returns:
    
    The proxied object or the original one if it does not implement a JDBC interface.
  - getNewJdbcInterfaceProxy
```
protected java.lang.reflect.InvocationHandler getNewJdbcInterfaceProxy(java.lang.Object toProxy)
```
    Instantiates a new JdbcInterfaceProxy for the given object. Subclasses can override this to return instances of JdbcInterfaceProxy subclasses.
    
    Parameters:
    
    toProxy - The object instance to be proxied.
    
    Returns:
    
    The new InvocationHandler instance.
  - dealWithInvocationException
```
protected void dealWithInvocationException(java.lang.reflect.InvocationTargetException e)
                                    throws java.sql.SQLException,
                                           java.lang.Throwable,
                                           java.lang.reflect.InvocationTargetException
```
    Deals with InvocationException from proxied objects.
    
    Parameters:
    
    e - The Exception instance to check.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
    
    java.lang.Throwable - if an error occurs
    
    java.lang.reflect.InvocationTargetException - if an error occurs
  - shouldExceptionTriggerConnectionSwitch
```
protected abstract boolean shouldExceptionTriggerConnectionSwitch(java.lang.Throwable t)
```
    Checks if the given throwable should trigger a connection switch.
    
    Parameters:
    
    t - The Throwable instance to analyze.
    
    Returns:
    
    true if the given throwable should trigger a connection switch
  - isSourceConnection
```
protected abstract boolean isSourceConnection()
```
    Checks if current connection is to a source host.
    
    Returns:
    
    true if current connection is to a source host
  - invalidateCurrentConnection
```
protected void invalidateCurrentConnection()
                                    throws java.sql.SQLException
```
    Invalidates the current connection.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - invalidateConnection
```
protected void invalidateConnection(JdbcConnection conn)
                             throws java.sql.SQLException
```
    Invalidates the specified connection by closing it.
    
    Parameters:
    
    conn - The connection instance to invalidate.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - pickNewConnection
```
protected abstract void pickNewConnection()
                                   throws java.sql.SQLException
```
    Picks the "best" connection to use from now on. Each subclass needs to implement its connection switch strategy on it.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - createConnectionForHost
```
protected ConnectionImpl createConnectionForHost(HostInfo hostInfo)
                                          throws java.sql.SQLException
```
    Creates a new physical connection for the given HostInfo.
    
    Parameters:
    
    hostInfo - The host info instance.
    
    Returns:
    
    The new Connection instance.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - syncSessionState
```
protected void syncSessionState(JdbcConnection source,
                                JdbcConnection target,
                                boolean readOnly)
                         throws java.sql.SQLException
```
    Synchronizes session state between two connections, allowing to override the read-only status.
    
    Parameters:
    
    source - The connection where to get state from.
    
    target - The connection where to set state.
    
    readOnly - The new read-only status.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - doClose
```
protected abstract void doClose()
                         throws java.sql.SQLException
```
    Executes a close() invocation;
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - doAbortInternal
```
protected abstract void doAbortInternal()
                                 throws java.sql.SQLException
```
    Executes a abortInternal() invocation;
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - doAbort
```
protected abstract void doAbort(java.util.concurrent.Executor executor)
                         throws java.sql.SQLException
```
    Executes a abort() invocation;
    
    Parameters:
    
    executor - executor
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - 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
  - invokeMore
```
protected abstract java.lang.Object invokeMore(java.lang.Object proxy,
                                               java.lang.reflect.Method method,
                                               java.lang.Object[] args)
                                        throws java.lang.Throwable
```
    Continuation of the method invocation process, to be implemented within each subclass.
    
    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

Class MultiHostConnectionProxy

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

hostsList

connectionUrl

autoReconnect

thisAsConnection

currentConnection

isClosed

closedExplicitly

closedReason

lastExceptionDealtWith

Constructor Detail

MultiHostConnectionProxy

Method Detail

getProxy

getParentProxy

setProxy

propagateProxyDown

proxyIfReturnTypeIsJdbcInterface

getNewJdbcInterfaceProxy

dealWithInvocationException

shouldExceptionTriggerConnectionSwitch

isSourceConnection

invalidateCurrentConnection

invalidateConnection

pickNewConnection

createConnectionForHost

syncSessionState

doClose

doAbortInternal

doAbort

invoke

invokeMore

allowedOnClosedConnection