Javaee-jdbc, javaee

Javaee-jdbc, javaee

1. First import the jdbc-mysql package

2. Program Framework:

3. Database Configuration File

Driver = com. mysql. jdbc. Driver
Url = jdbc: mysql: // localhost: 3306/jdbc_db
Username = root
Password = 1234

4. Access the underlying data:

Package cn.com. dale. utils;

Import java. io. IOException;
Import java. SQL. Connection;
Import java. SQL. DriverManager;
Import java. SQL. SQLException;
Import java. util. Properties;

Public class Utils {

Public Connection openConnection (){
Properties pro = new Properties ();
Try {
Pro. load (this. getClass (). getClassLoader (). getResourceAsStream ("DBConfig. properties "));
String driver = pro. getProperty ("driver ");
String url = pro. getProperty ("url ");
String username = pro. getProperty ("username ");
String password = pro. getProperty ("password ");

Class. forName (driver );
Return DriverManager. getConnection (url, username, password );
} Catch (IOException e ){
E. printStackTrace ();
} Catch (Exception e ){
E. printStackTrace ();
}
Return null;
}

Public void closeConnection (Connection conn ){
Try {
Conn. close ();
} Catch (SQLException e ){
E. printStackTrace ();
}
}
}

5. javabean:

Package cn.com. dale. Bean;

Public class User {
Private String name;
Private String password;
Public String getName (){
Return name;
}
Public void setName (String name ){
This. name = name;
}
Public String getPassword (){
Return password;
}
Public void setPassword (String password ){
This. password = password;
}

}

6. interface:

Package cn.com. dale. Dao;

Import cn.com. dale. Bean. User;

Public interface UserDao {

// Denglu
Public User login (User user );
// Zhuce
Public void register (User user );
// Jiancha
Public boolean check (String name );

}

7. Interface implementation class:

Package cn.com. dale. DaoImpl;

Import java. SQL. Connection;
Import java. SQL. PreparedStatement;
Import java. SQL. ResultSet;
Import java. SQL. SQLException;

Import cn.com. dale. Bean. User;
Import cn.com. dale. Dao. UserDao;
Import cn.com. dale. utils. Utils;

Public class UserDaoImpl implements UserDao {

Public void register (User user ){

If (check (user. getName () = false ){
System. out. println ("this user name already exists! ");
Return;
}
String SQL = "insert into usertab (username, password) values (?,?) ";
Utils utils = new Utils ();
Connection conn = utils. openConnection ();
Try {
PreparedStatement stmt = conn. prepareStatement (SQL );
Stmt. setString (1, user. getName ());
Stmt. setString (2, user. getPassword ());

Stmt.exe cuteUpdate ();
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Finally {
Utils. closeConnection (conn );
}
}

Public User login (User user ){
String SQL = "select * from usertab where username =? And password =? ";
Utils utils = new Utils ();
Connection conn = utils. openConnection ();
Try {
PreparedStatement stmt = conn. prepareStatement (SQL );
Stmt. setString (1, user. getName ());
Stmt. setString (2, user. getPassword ());
ResultSet rs = stmt.exe cuteQuery ();
If (rs. next ()){
Return user;
}
} Catch (SQLException e ){
// TODO Auto-generated catch block
E. printStackTrace ();
} Finally {
Utils. closeConnection (conn );
}
Return null;
}


Public boolean check (String name ){
String SQL = "select * from usertab where username =? ";

Utils utils = new Utils ();
Connection conn = utils. openConnection ();
Try {
PreparedStatement stmt = conn. prepareStatement (SQL );
Stmt. setString (1, name );
ResultSet rs = stmt.exe cuteQuery ();
If (rs. next ()){
Return false;
}
} Catch (SQLException e ){
E. printStackTrace ();
} Finally {
Utils. closeConnection (conn );
}
Return true;
}
}

8. test:

Package cn.com. dale. test;

Import org. junit. Test;

Import cn.com. dale. Bean. User;
Import cn.com. dale. Dao. UserDao;
Import cn.com. dale. DaoImpl. UserDaoImpl;

Public class test01 {

@ Test
Public void test (){
// Utils utils = new Utils ();
// System. out. println (utils. openConnection ());

User user = new User ();
User. setName ("Small non ");
User. setPassword ("123 ");

UserDao userDao = new UserDaoImpl ();
UserDao. register (user );

User user1 = userDao. login (user );
System. out. println (user1.getName () + ":" + user1.getPassword ());

}
}