jdbc 操作步骤

 package org.db;

 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;

 public class DBConn {

 //    public final static String URL = "jdbc:mysql://localhost:3306/test?useSSL=false";
     public final static String URL = "jdbc:mysql://localhost:3306/test?characterEncoding=utf8"; //可以指定jdbc编码方式
     public final static String USERNAME = "root";
     public final static String PASSWORD = "000000";
     public final static String DRIVER = "com.mysql.jdbc.Driver";

     public static Connection conn;
     public static Connection getConn(){
         try {
             Class.forName(DRIVER);
             conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
             if (conn!=null) {
                 System.out.println("连接成功");
             }
             return conn;
         } catch (Exception e) {
             e.printStackTrace();
             System.out.println("连接失败");
             return null;
         }
     }
     public static void closeConn(){
         try {
             if(conn!=null){
                 conn.close();
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }
 }

 package org.test;

 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;

 import org.db.DBConn;
 import org.model.Login;

 public class test {

     public static void main(String[] args) {
         Connection conn = DBConn.getConn();
         if (conn!=null) {
             System.out.println("连接成功");
             try {
                 conn = DBConn.getConn();
                 String sql = "select id,name,password,role from mbook where name=? and password=?";
                 PreparedStatement ps = conn.prepareStatement(sql);
                 ps.setString(1,"张三");
                 ps.setString(2,"000000");
                 ResultSet rs = ps.executeQuery();

                     while (rs.next()) {
                     Login login = new Login();
                     login.setId(rs.getInt(1));
                     login.setName(rs.getString(2));
                     login.setPassword(rs.getString(3));
                     login.setRole(rs.getBoolean(4));
                     System.out.println("得到数据："+login);
                     }
             } catch (SQLException e) {
                 e.printStackTrace();
             }finally{
                 DBConn.closeConn();
             }
         }
     }
 }