JAVA知识：Class.forName的含义

Class aClass = Class.forName(xxx.xx.xx);
Object anInstance = aClass.newInstance();
Class.forName("").newInstance()返回的是object
but there is some limit for this method to create instance
that is your class constructor should no contain parameters, 
and you should cast the instance manually.
Class Driver{
protected static Driver current;
public static Driver getDriver(){
return current;
}
}
Class MyDriver extends Driver{
static{
Driver.current=new MyDriver();
}
MyDriver(){}
                        }

Class.forName("MyDriver");
            Driver d=Driver.getDriver();c

public class MyJDBCDriver implements Driver {
static {
DriverManager.registerDriver(new MyJDBCDriver());
}
            }