Class.forName () and newinstance ()

1 Importjava.sql.Connection;2 ImportJava.sql.DriverManager;3 ImportJava.sql.ResultSet;4 Importjava.sql.Statement;5 Importjava.util.Date;6 7 8  Public classNewinstanceexample {9 Ten      Public Static voidMain (string[] args)throwsException { One         //Class.forName () requires the JVM to find and load the specified class A         //newinstance () Gets an instance of the class -         //newinstance () method differs from the New keyword: one is a method, one is a keyword, and newinstance () can only call a parameterless constructor -         //forname and newinstance gain greater flexibility and provide a means of decoupling theDate date = Java.util.Date.class. newinstance (); -         LongTime =date.gettime (); - System.out.println (time); -          +class<?> Dateclass = Class.forName ("Java.util.Date"); -Date Date2 =(Date) dateclass.newinstance (); +         LongTime2 =date2.gettime (); A System.out.println (time2); at          - mysqlconnection (); -          -     } -      -      Public Static voidMysqlconnection ()throwsException { in         //It is explicitly required in the JDBC specification that the driver class must register itself with DriverManager -         //similar to the following: to         /* + Public class Myjdbcdriver implements Driver { - Static { the Drivermanager.registerdriver (New Myjdbcdriver ()); *             } $         }Panax Notoginseng         */ -         //Class.forName () executes a static block of code when the Com.mysql.jdbc.Driver is loaded, registering itself with DriverManager theClass.forName ("Com.mysql.jdbc.Driver"); +String url = "Jdbc:mysql://localhost/test?useunicode=true&&characterencoding=utf-8&autoreconnect=true "; AString user = "root"; theString password = "123456"; +          -Connection conn =NULL;  $Statement stmt =NULL;  $ResultSet rs =NULL;  -         Try {   -conn =drivermanager.getconnection (URL, user, password); thestmt =conn.createstatement (); -String sql = "Select Deptno,deptname from dept";//Dept This table has a deptno,deptname fieldWuyirs = stmt.executequery (SQL);//Execute SQL statement the              while(Rs.next ()) { -System.out.print (Rs.getint ("deptno") + ""); WuSystem.out.println (rs.getstring ("Deptname")); -             } About}Catch(Exception e) { $             Throwe; -}finally { - rs.close (); - stmt.close (); A conn.close (); +         }   the     } -}

Class.forName () and newinstance ()