try{ 
 //加载MySql的驱动类 
 Class.forName("com.mysql.jdbc.Driver") ; 
 }catch(ClassNotFoundException e){ 
 System.out.println("找不到驱动程序类 ，加载驱动失败！"); 
 e.printStackTrace() ; 
 }

//连接MySql数据库，用户名和密码都是root 
  String url = "jdbc:mysql://localhost:3306/test" ;  
  String username = "root" ; 
  String password = "root" ; 
  try{ 
 Connection con =  
    DriverManager.getConnection(url , username , password ) ; 
  }catch(SQLException se){ 
 System.out.println("数据库连接失败！"); 
 se.printStackTrace() ; 
  } 

Statement stmt = con.createStatement() ; 
PreparedStatement pstmt = con.prepareStatement(sql) ; 
CallableStatement cstmt = con.prepareCall("{CALL demoSp(? , ?)}") ; 

ResultSet rs = stmt.executeQuery("SELECT * FROM ...") ; 
int rows = stmt.executeUpdate("INSERT INTO ...") ; 
boolean flag = stmt.execute(String sql) ; 

while(rs.next()){ 
   String name = rs.getString("name") ; 
 String pass = rs.getString(1) ; // 此方法比较高效 
  } 

 if(rs != null){ // 关闭记录集 
 try{ 
  rs.close() ; 
 }catch(SQLException e){ 
  e.printStackTrace() ; 
 } 
 } 
 if(stmt != null){ // 关闭声明 
 try{ 
  stmt.close() ; 
 }catch(SQLException e){ 
  e.printStackTrace() ; 
 } 
 } 
 if(conn != null){ // 关闭连接对象 
 try{ 
  conn.close() ; 
 }catch(SQLException e){ 
  e.printStackTrace() ; 
 } 
 }

package com.b510; 
 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
/** 
 * 
 * @author Hongten</br> 
 * @date 2012-7-16 
 * 
 */
public class JDBCTest { 
  public static void main(String[] args) { 
    String driver = "com.mysql.jdbc.Driver"; 
    String dbName = "spring"; 
    String passwrod = "root"; 
    String userName = "root"; 
    String url = "jdbc:mysql://localhost:3308/" + dbName; 
    String sql = "select * from users"; 
 
    try { 
      Class.forName(driver); 
      Connection conn = DriverManager.getConnection(url, userName, 
          passwrod); 
      PreparedStatement ps = conn.prepareStatement(sql); 
      ResultSet rs = ps.executeQuery(); 
      while (rs.next()) { 
        System.out.println("id : " + rs.getInt(1) + " name : "
            + rs.getString(2) + " password : " + rs.getString(3)); 
      } 
 
      // 关闭记录集 
      if (rs != null) { 
        try { 
          rs.close(); 
        } catch (SQLException e) { 
          e.printStackTrace(); 
        } 
      } 
 
      // 关闭声明 
      if (ps != null) { 
        try { 
          ps.close(); 
        } catch (SQLException e) { 
          e.printStackTrace(); 
        } 
      } 
 
      // 关闭链接对象 
      if (conn != null) { 
        try { 
          conn.close(); 
        } catch (SQLException e) { 
          e.printStackTrace(); 
        } 
      } 
 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
  } 
 
}