Hello Naga,
try this code:
var envconn = system.getConnector("ibmdi.JDBC");
envconn.setParam ("jdbcSource","jdbc:db2://server:port/schema");
envconn.setParam ("jdbcDriver","com.ibm.db2.jcc.DB2Driver");
envconn.setParam ("jdbcLogin","userid");
envconn.setParam ("jdbcPassword","*******");
envconn.setParam ("jdbcSchema","schemaname");
envconn.setParam ("jdbcTable","tablename");
task.logmsg("connection successfull");
// Use null to initialize the call instead of mode setting
envconn.initialize (null);
task.logmsg("connection successfull2 ");