Question

I’m fairly confused about the Class.forName in java. how do we explain what Class.forName is from a C# perspective?

use case: java.lang.Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);

Answer 1

Class.forName returns an instance of a Class object. Class is equivalent to the c# class object.

Class.forName forces classes to load, if they have not already been loaded. As part of the class loading process is invoking any static blocks defined in the class. A static block looks like,

class Foo {
    static {
         System.out.println("loaded Foo");
    }
}

//running this will print "loaded Foo"
Class.forName("Foo");

Static blocks are invoked only once, the first time a class is loaded, so repeatedly calling Class.forName(“Foo”) will only cause “loaded Foo” to be printed once. Creating a new instance of Foo will also cause the class to be loaded, if it has not already been loaded.

Generally, JDBC drivers will register themselves by calling DriverManager.registerDriver() in a static block, which is why calling Class.forName() loads the driver.