KwCheng's blog

Before we do any operation for database , we should know how to connect the Mysql database 

throuth JDBC.

The example is as below :

 
import java.sql.*; 
 
public class DBConnectionDemo 

{ 
    public static void main(String[] args) 

   { 
        String driver = "com.mysql.jdbc.Driver"; 

 String url = "jdbc:mysql://localhost:3306/GUESTBOOK"; 

        String user = "root"; 

        String password = "123456"; 

        try 

       { 
            Class.forName(driver); 

 Connection conn = DriverManager.getConnection(url, user, password);
 
            if(conn != null && !conn.isClosed()) 

           {
                System.out.println("資料庫連線測試成功！"); 

                conn.close();
            }
            
        } 
        catch(ClassNotFoundException e) 

       { 

            System.out.println("找不到驅動程式類別"); 

            e.printStackTrace(); 

        } 

        catch(SQLException e) 

        { 

            e.printStackTrace(); 

        } 

    } 

} 

First , We should load the JDBC driver into the JVM environment , so we use the code :

 String driver = "com.mysql.jdbc.Driver"; 

 Class.forName(driver); 

Then , we can connect to the database , we tell JDBC driver the database we used , the ip address and port of our database , 

and we also tell him the database which we want to connect.

String url = "jdbc:mysql://localhost:3306/GUESTBOOK"; 

Connection conn = DriverManager.getConnection(url, user, password);

ref : http://caterpillar.onlyfun.net/Gossip/JavaGossip-V2/ConnectDB.htm