jdbc的操作流程代码

` // dbhelp help类，封装数据库基本信息以及关闭资源的方法

1class DbHelp{
2    //数据库连接信息
3    public static String url = "jdbc:mysql://localhost:3306/blog";
4    public static String user = "root";
5    public static String password = "root";
6    public static String driver = "com.mysql.jdbc.Driver";
7
8    public static PreparedStatement ps = null;
9
10    public static Connection conn = null;
11
12    public ResultSet rs = null;
13
14    //获取数据库连接的方法
15    public static void getConnection(){
16    try {
17	        Class.forName(driver);
18	        conn = DriverManager.getConnection(url, user, password);
19	        } catch (ClassNotFoundException e) {
20	                e.printStackTrace();
21	        } catch (SQLException e) {
22	                e.printStackTrace();
23	        }
24    }
25
26    // 关闭资源
27    public void close(){
28      try {
29		        ps.close();
30		        conn.close();
31                rs.close();
32	        } catch (SQLException e) {
33		            e.printStackTrace();
34	        }
35        }
36    }
37
38// User实体类
39public class User{
40private int id;
41private String name;
42private  String contact;
43private String telephone;
44private String email;
45private String remark;
46private String userName;
47private String address;
48
49
50@Override
51public String toString() {
52return "User [id=" + id + ", name=" + name + ", contact=" + contact
53+ ", telephone=" + telephone + ", email=" + email + ", remark="
54+ remark + ", userName=" + userName + ", address=" + address+ "]";
55}
56    // get/set 方法
57    。。。。。。
58}    
59
60
61
62 //数据库操作类
63public class UserDemo extends DbHelp{
64
65    public User getUser(){
66        getConnection();
67        User user = new User();
68        String sql = "select * from t_sys_user where user_id = ?";
69        try{
70            ps = conn.prepareStatement(sql);
71            // 设置参数，第一个问号的值为 8
72            ps.setInt(1,8)
73            rs = ps.executeQuery();
74            while(rs.next()){
75                user.setId(rs.getInt("id"));
76                user.setName(rs.getString("name"));
77                user.setContact(rs.getString("contact"));
78                user.setEmail(rs.getString("email"));
79                user.setRemark(rs.getString("remark"));
80                user.setTelephone(rs.getString("telephone"));
81            }
82            }catch(SQLException e){
83                e.printStackTrace();
84        } 
85            //关闭资源
86            close();
87            return user;
88        }
89    }
90
91  //测试方法
92public static void main(String[] a){
93        UserDemo demo = new UserDemo();
94        User user = demo.get();
95        System.out.println(user.toString());
96}

`