java连接mysql数据库示例，javamysql示例,import java.

java连接mysql数据库示例，javamysql示例,import java.

import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class classname {    public static String url = "jdbc:mysql://localhost:3306/test";//characterEncoding=GBK    public static String username = "root";    public static String password = "root";    public static Connection con;    public static Statement stmt;    public static ResultSet rs;    public static PreparedStatement pstmt;    public static void main(String[] args) throws SQLException {        connect();        //select();        //insert();        //update();        //delete();        close();    }    public static void connect() {        // 定位驱动        try {            Class.forName("com.mysql.jdbc.Driver");            System.out.println("加载驱动成功!");         } catch (ClassNotFoundException e) {            System.out.println("加载驱动失败!");            e.printStackTrace();        }        // 建立连接        try {            con = DriverManager.getConnection(url, username, password);            stmt = con.createStatement();            System.out.println("数据库连接成功!");         } catch(SQLException e) {            System.out.println("数据库连接失败!");            e.printStackTrace();        }    }    public static void select() {        try {         String sql="select * from test where name=? ";             pstmt=con.prepareStatement(sql);            pstmt.setString(1,"root");          //String sql="select * from test where name='root' ";             //rs = stmt.executeQuery(sql);           rs=pstmt.executeQuery();            while (rs.next()) {             System.out.println("你的第一个字段内容为："+rs.getString("name"));              System.out.println("你的第二个字段内容为："+rs.getInt(1));             }            rs.close();        }catch (Exception e) {            System.out.println("数据查询失败!");            e.printStackTrace();        }    }    public static void insert() {        try {         String sql="insert into test (id,name) values('2','admin')";         stmt.executeUpdate(sql);            System.out.println("数据插入成功!");        }catch (Exception e) {            System.out.println("数据插入失败!");            e.printStackTrace();        }    }    public static void update() {        try {         String sql="update test set name='rootroot' where id=1";            stmt.executeUpdate(sql);            System.out.println("数据更新成功!");        }catch (Exception e) {            System.out.println("数据更新失败!");            e.printStackTrace();        }    }    public static void delete() {        try {         String sql="delete from test where id=?";          pstmt = con.prepareStatement(sql);             pstmt.setInt(1,1);             pstmt.executeUpdate();            System.out.println("数据删除成功!");        }catch (Exception e) {            System.out.println("数据删除失败!");            e.printStackTrace();        }    }    public static void close() {     try{      if(rs!=null)             rs.close();      if(stmt!=null)             stmt.close();      if(con!=null)             con.close();     }catch(Exception e)     {      e.printStackTrace();     }    }}