5.4 Applying Connection Labels in UCP

Labels are applied on a borrowed connection using the applyConnectionLabel method from the LabelableConnection interface. This method is typically called from the configure method of the labeling callback. Any number of connection labels may be cumulatively applied on a borrowed connection. Each time a label is applied to a connection, the supplied key/value pair is added to the collection of labels already applied to the connection. Only the last applied value is retained for any given key.


A labeling callback must be registered on the connection pool before a label can be applied on a borrowed connection; otherwise, an exception is thrown.

The following example demonstrates initializing a connection with a transaction isolation level and then applying a label to the connection:

String pname = "property1";
String pvalue = "value";
Connection conn = pds.getConnection();

// initialize the connection as required.


((LabelableConnection) conn).applyConnectionLabel(pname, pvalue);

In order to remove a given key from the set of connection labels applied, apply a label with the key to be removed and a null value. This may be used to clear a particular key/value pair from the set of connection labels.