JDBC for Oracle - Herong's Tutorial Examples - v3.13, by Herong Yang
Establishing Connections from JDBC to Databases
This section provides some quick information on establishing connections from JDBC to databases.
JDBC API offers two different ways to establish a connection to the database server:
1. Using DrirverManager Class: DriverManager.getConnection(connection_url) - The driver manager passes the connection URL to all loaded JDBC drivers, hoping that one of them will recognize the URL and creates a connection. See sample code below:
// Loading a JDBC driver Class.forName("acme.db.Driver"); // Creating a connection String url = "jdbc:odbc:fred"; Connection con = DriverManager.getConnection(url,"user","pass");
2. Using DataSource Object: ds.getConnection() - A DataSource object should be configured and registered with a JNDI (Java Naming and Directory Interface) directory service only once. When a connection is needed, the registered DataSource object can be retrieved back from JNDI. A connection can be then created from the retrieved DataSource object.
// Registering a DataSource VendorDataSource vds = new VendorDataSource(); vds.setServerName("my_database_server"); vds.setDatabaseName("my_database"); vds.setDescription("the data source for inventory and personnel"); Context ctx = new InitialContext(); ctx.bind("jdbc/AcmeDB", vds); // Creating a connection Context ctx = new InitialContext(); DataSource ds = (DataSource)ctx.lookup("jdbc/AcmeDB"); Connection con = ds.getConnection("genius", "abracadabra");
JDK documentation suggests to use DataSource object to create connection objects whenever possible.
Table of Contents
►JDBC (Java Database Connectivity) Introduction
►Establishing Connections from JDBC to Databases
DriverManager - Loading JDBC Driver
DriverManager - Connection URL
Oracle Express Edition Installation on Windows
Oracle - Reference Implementation of JdbcRowSet
Oracle - JBDC CallableStatement
Oracle CLOB (Character Large Object) - TEXT
Oracle BLOB (Binary Large Object) - BLOB