What is the actual use of Class forName oracle jdbc driver OracleDriver while connecting to a database

Question

What will the command   Class forName  oracle jdbc driver OracleDriver     exactly do while connecting to a Oracle database  Is there an alternate way of doing the same thing

User · Accepted Answer

It obtains a reference to the class object with the FQCN (fully qualified class name) oracle.jdbc.driver.OracleDriver.

It doesn't "do" anything in terms of connecting to a database, aside from ensure that the specified class is loaded by the current classloader. There is no fundamental difference between writing

Class<?> driverClass = Class.forName("oracle.jdbc.driver.OracleDriver");
// and
Class<?> stringClass = Class.forName("java.lang.String");

Class.forName("com.example.some.jdbc.driver") calls show up in legacy code that uses JDBC because that is the legacy way of loading a JDBC driver.

From The Java Tutorial:

In previous versions of JDBC, to obtain a connection, you first had to initialize your JDBC driver by calling the method Class.forName. This methods required an object of type java.sql.Driver. Each JDBC driver contains one or more classes that implements the interface java.sql.Driver.
...
Any JDBC 4.0 drivers that are found in your class path are automatically loaded. (However, you must manually load any drivers prior to JDBC 4.0 with the method Class.forName.)

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User · Answer

An alternative would to use the jdbc drivers System property to specify your required drivers s  on the command line when you start the JVM

User · Answer

From the Java JDBC tutorial      In previous versions of JDBC  to obtain a connection  you first had to initialize your JDBC driver by calling the method Class forName    Any JDBC 4 0 drivers that are found in your class path are automatically loaded   However  you must manually load any drivers prior to JDBC 4 0 with the method Class forName     So  if you re using the Oracle 11g  11 1  driver with Java 1 6  you don t need to call Class forName  Otherwise  you need to call it to initialise the driver

User · Answer

Use oracle jdbc OracleDriver  not oracle jdbc driver OracleDriver   You do not need to register it if the driver jar file is in the  WEB-INF lib  directory  if you are using Tomcat   Save this as test jsp and put it in your web directory  and redeploy your web app folder in Tomcat manager    lt    page import  java sql      gt    lt HTML gt   lt HEAD gt   lt TITLE gt Simple JSP Oracle Test lt  TITLE gt   lt  HEAD gt  lt BODY gt   lt   Connection conn   null  try       Class forName  oracle jdbc OracleDriver        conn   DriverManager getConnection  jdbc oracle thin  XXX XXX XXX XXX XXXX dbName    user    password        Statement stmt   conn createStatement        out println  Connection established       catch  Exception ex        out println  Exception      ex getMessage             finally       if  conn    null            try               conn close                         catch  Exception ignored                   ignore                      gt

User · Answer

It registers the driver  something of the form   public class SomeDriver implements Driver     static       try         DriverManager registerDriver new SomeDriver           catch  SQLException e             TODO Auto-generated catch block                etc  implemented methods

User · Answer

Pre Java 6 the DriverManager class wouldn t have known which JDBC driver you wanted to use  Class forName        was a way on pre-loading the driver classes   If you are using Java 6 you no longer need to do this

User · Answer

This command loads class of Oracle jdbc driver to be available for DriverManager instance  After the class is loaded system can connect to Oracle using it  As an alternative you can use registerDriver method of DriverManager and pass it with instance of JDBC driver you need

[java] What is the actual use of Class.forName("oracle.jdbc.driver.OracleDriver") while connecting to a database?

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[java] What is the actual use of Class.forName("oracle.jdbc.driver.OracleDriver") while connecting to a database?

Further reading (read: questions this is a dup of)

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