Package org.apache.tomcat.jdbc.pool.interceptor

Class ConnectionState

java.lang.Object

org.apache.tomcat.jdbc.pool.JdbcInterceptor

org.apache.tomcat.jdbc.pool.interceptor.ConnectionState

All Implemented Interfaces:

java.lang.reflect.InvocationHandler

public class ConnectionState
extends JdbcInterceptor

Interceptor that keep track of connection state to avoid roundtrips to the database. The ConnectionPool is optimized to do as little work as possible. The pool itself doesn't remember settings like Connection.setAutoCommit(boolean), Connection.setReadOnly(boolean), Connection.setCatalog(String) or Connection.setTransactionIsolation(int). It relies on the application to remember how and when these settings have been applied. In the cases where the application code doesn't know or want to keep track of the state, this interceptor helps cache the state, and it also avoids roundtrips to the database asking for it.

Field Summary

Fields

Modifier and Type	Field	Description
protected java.lang.Boolean	autoCommit	Cached auto-commit state of the connection.
protected java.lang.String	catalog	Cached catalog (database) name of the connection.
protected java.lang.Boolean	readOnly	Cached read-only state of the connection.
protected java.lang.String[]	readState	Method names for reading connection state.
protected java.lang.Integer	transactionIsolation	Cached transaction isolation level of the connection.
protected java.lang.String[]	writeState	Method names for writing connection state.

Fields inherited from class org.apache.tomcat.jdbc.pool.JdbcInterceptor

CLOSE_VAL, EQUALS_VAL, GETCONNECTION_VAL, HASHCODE_VAL, ISCLOSED_VAL, ISVALID_VAL, ISWRAPPERFOR_VAL, properties, TOSTRING_VAL, UNWRAP_VAL

Constructor Summary

Constructors

Constructor	Description
ConnectionState()	Creates a new ConnectionState interceptor instance.

Method Summary

Modifier and Type	Method	Description
void	disconnected(ConnectionPool parent, PooledConnection con, boolean finalizing)	Called when Connection.close() is called on the underlying connection.
java.lang.Object	invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)	Gets invoked each time an operation on Connection is invoked.
void	reset(ConnectionPool parent, PooledConnection con)	Gets called each time the connection is borrowed from the pool This means that if an interceptor holds a reference to the connection the interceptor can be reused for another connection.

Methods inherited from class org.apache.tomcat.jdbc.pool.JdbcInterceptor

compare, compare, getNext, getProperties, isUseEquals, poolClosed, poolStarted, setNext, setProperties, setUseEquals

Methods inherited from class java.lang.Object

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

Field Detail

readState

protected final java.lang.String[] readState

Method names for reading connection state.

writeState

protected final java.lang.String[] writeState

Method names for writing connection state.

autoCommit

protected java.lang.Boolean autoCommit

Cached auto-commit state of the connection.

transactionIsolation

protected java.lang.Integer transactionIsolation

Cached transaction isolation level of the connection.

readOnly

protected java.lang.Boolean readOnly

Cached read-only state of the connection.

catalog

protected java.lang.String catalog

Cached catalog (database) name of the connection.

Constructor Detail

ConnectionState

public ConnectionState()

Creates a new ConnectionState interceptor instance.

Method Detail

reset

public void reset(ConnectionPool parent,
                  PooledConnection con)

Description copied from class: JdbcInterceptor

Gets called each time the connection is borrowed from the pool This means that if an interceptor holds a reference to the connection the interceptor can be reused for another connection.
This method may be called with null as both arguments when we are closing down the connection.

Specified by:

reset in class JdbcInterceptor

Parameters:

parent - - the connection pool owning the connection

con - - the pooled connection

disconnected

public void disconnected(ConnectionPool parent,
                         PooledConnection con,
                         boolean finalizing)

Description copied from class: JdbcInterceptor

Called when Connection.close() is called on the underlying connection. This is to notify the interceptors, that the physical connection has been released. Implementation of this method should be thought through with care, as no actions should trigger an exception.

Overrides:

disconnected in class JdbcInterceptor

Parameters:

parent - - the connection pool that this connection belongs to

con - - the pooled connection that holds this connection

finalizing - - if this connection is finalizing. True means that the pooled connection will not reconnect the underlying connection

invoke

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

Description copied from class: JdbcInterceptor

Gets invoked each time an operation on Connection is invoked.

Specified by:

invoke in interface java.lang.reflect.InvocationHandler

Overrides:

invoke in class JdbcInterceptor

Throws:

java.lang.Throwable