[ http://issues.apache.org/jira/browse/DERBY-243?page=comments#action_65821 ] David Van Couvering commented on DERBY-243: -------------------------------------------
In response to Kathey's request, I am providing information on the semantics for providing a unique string representation for a connection. First, it is important to identify three major types of connections in Derby: POOLED CONNECTIONS Pooled Connections are a subtype of javax.sql.PooledConnection. They represent a connection stored on a pool. References to PooledConnections are never directly visible to application code. They are used by implementors of connection pools so that management of pooled connections can be standardized across JDBC driver providers. PROXY CONNECTIONS Proxy connections are a class of connections that, although they implement the java.sql.Connection interface, don't directly implement the methods of java.sql.Connection. Instead, they act as a proxy to an underlying physical connection, and allow containers to "inject" container logic when key connectoin lifecycle events occur. These are also sometimes called "logical connections" or "brokered connections". PHYSICAL CONNECTIONS These are the connection classes that do the "heavy lifting" of actually implementing the methods on java.sql.Connection. They are the underlying physical connections wrapped by proxy connections. CONNECTION STRING SEMANTICS With these definitions in place, here are the semantics of connection strings: - When a physical connection is created, it is assigned a unique UUID that is unchanged for the lifetime of the connection. - When an application calls Connection.toString(), it gets the string "Connection_<UUID>" of the underlying physical connection, regardless of where the application has a reference to the physical connection itself a reference to a proxy connection (aka brokered connection) that wraps the physical connection. - A pooled connection is assigned a separate UUID from a physical connection. When a container calls PooledConnection.toString(), it gets the string "PooledConnection_<UUID>". This is useful for developers implementing connection pools when they are trying to debug pooled connections > connection toString should uniquely identify the connection > ----------------------------------------------------------- > > Key: DERBY-243 > URL: http://issues.apache.org/jira/browse/DERBY-243 > Project: Derby > Type: Improvement > Components: JDBC > Reporter: Kathey Marsden > Assignee: David Van Couvering > Priority: Trivial > Fix For: 10.0.2.0, 10.0.2.1, 10.0.2.2, 10.1.0.0 > Attachments: DERBY-243.diff > > The toString() on the Derby connection doesn't print > unique information. > for example System.out.println(conn) prints: > EmbedConnection in the case of derby embedded > It would be great if the toString() method for connections could be used to > differentiate one connection from another. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
