What purpose does Class.forName() serve if you don't use the return value?

Question

I've seen this line in a sample application for using a commercial JDBC driver:

Class.forName("name.of.a.jcdb.driver") 

The return value is not used.

What purpose does this line serve?

Answer 1

It performs a static loading of that class. So anything in the static { } block, will run.

Answer 2

Maybe some code snippet will help. This is from Sun's JDBC-ODBC bridge driver,

//-------------------------------------------------------------------- // Static method to be executed when the class is loaded. //--------------------------------------------------------------------   static {            JdbcOdbcTracer tracer1 = new JdbcOdbcTracer();     if (tracer1.isTracing ()) {         tracer1.trace ("JdbcOdbcDriver class loaded");     }      JdbcOdbcDriver driver = new JdbcOdbcDriver ();      // Attempt to register the driver      try {         DriverManager.registerDriver (driver);     }     catch (SQLException ex) {         if (tracer1.isTracing ()) {             tracer1.trace ("Unable to register driver");         }       } } 

the DriverManager.registerDriver() call in a static block is executed whenever the driver is loaded through Class.forName().

This used to be the only way to register the driver. JDBC 4.0 introduced a new service registration mechanism so you don't need to do this anymore with newer JDBC 4.0 compliant drivers.