BEA WebLogic Server Tuning Guide

2.1 Connection Management

A key area of resource usage in multi-tier enterprise applications is the definition and management of connections

between applications and databases.

One simple type of connection is a one-to-one mapping between an application and a database. An application

requests a database connection from the relevant database driver and executes various statements using the

connection. When finished, the application releases the connection.

The following code fragment shows how a typical standalone application might acquire and use JDBC Connections

using the DriverManager interfaces. Java applications (in particular J2EE applications) can also use the Datasource

interfaces to obtain connections. The purpose of the code below is to introduce the user to the management of

connections in application programs prior to the introduction of connection pooling concepts.

An application using the DriverManager interface is provided below, followed by one using the DataSource

interface.

Code Listing 1: Sample JDBC application using DriverManager interface

try

{

String dbdriver = “com.dbvendor.driver”;

String dburl = “jdbc.vendordb.specific-optional-string”;

String username = “scott”;

String password = “tiger”;

// The above values can also be looked up from a JNDI tree

// dynamically to avoid hardcoding them in the source code

Class.forName(dbdriver).newInstance();

Connection dbconn = DriverManager.getConnection(dburl, username, password);

// Execute db statements using the connection

dbconn.close();

}

catch (Exception e)

{

//handle exceptions

}

Code Listing 2: Sample JDBC application using DataSource interface

// As part of application configuration/setup, a Datasource object

// for a database is bound to the JNDI. Now if the database used

// changes from one vendor to another, only the JNDI registration

// part of application environment has to change.

VendorDataSource v = new VendorDataSource();

try

{

Context ctx = new InitialContext();

ctx.bind(“jdbc/warehouseDS”, v)

}

catch (NamingException exc)

{

// handle exceptions

}