1 import java.sql.Connection; 2 import java.sql.DriverManager; 3 import java.sql.ResultSet; 4 import java.sql.SQLException; 5 import java.sql.Statement; 6  7 public class DBConnection 8 { 9 10     public static void main(String[] args)11     {12         String driver = "com.mysql.jdbc.Driver";13 14         //localhost指本机，也可以用本地ip地址代替，3306为MySQL数据库的默认端口号，“user”为要连接的数据库名15         String url = "jdbc:mysql://localhost:3306/user";16 17         //填入数据库的用户名跟密码18         String username = "test";19         String password = "test";20         String sql = "select * from user";//编写要执行的sql语句，此处为从user表中查询所有用户的信息21 22         try23         {24             Class.forName(driver);//加载驱动程序，此处运用隐式注册驱动程序的方法25 26         }27         catch(ClassNotFoundException e)28         {29             e.printStackTrace();30         }31         try32         {33             Connection con = DriverManager.getConnection(url,username,password);//创建连接对象34             Statement st = con.createStatement();//创建sql执行对象35             ResultSet rs = st.executeQuery(sql);//执行sql语句并返回结果集36 37             while(rs.next())//对结果集进行遍历输出38             {39 40                 System.out.println("username: "+rs.getString(1));//通过列的标号来获得数据41                 System.out.println("useradd: "+rs.getString("useradd"));//通过列名来获得数据42                 System.out.println("userage: "+rs.getInt("userage"));43             }44             //关闭相关的对象45             if(rs != null)46             {47                 try48                 {49                     rs.close();50                 }51                 catch(SQLException e)52                 {53                     e.printStackTrace();54                 }55             }56 57             if(st != null)58             {59                 try60                 {61                     st.close();62                 }63                 catch(SQLException e)64                 {65 66                     e.printStackTrace();67                 }68             }69 70             if(con !=null)71             {72 73                 try74                 {75 76                     con.close();77                 }78                 catch(SQLException e)79                 {80                     e.printStackTrace();81                 }82             }83         }84         catch(SQLException e)85         {86             e.printStackTrace();87         }88     }89 }