用ssm框架写登陆注册

好的，下面是使用SSM框架实现用户登录和注册的基本步骤：

1. 配置数据库连接信息

在Spring配置文件中配置数据库连接信息，例如MySQL数据库的连接信息：

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost:3306/dbname" />
    <property name="username" value="root" />
    <property name="password" value="password" />
</bean>

2. 创建数据表

创建用于存储用户信息的数据表，例如：

CREATE TABLE user (
    id INT(11) NOT NULL AUTO_INCREMENT,
    username VARCHAR(50) NOT NULL,
    password VARCHAR(50) NOT NULL,
    PRIMARY KEY (id)
);

3. 创建User实体类

创建User类，用于表示用户信息：

public class User {
    private int id;
    private String username;
    private String password;

    // getter and setter methods
}

4. 创建UserDao接口和实现类

创建UserDao接口和实现类，用于操作用户信息的数据库表：

public interface UserDao {
    public User getUserById(int id);
    public User getUserByUsername(String username);
    public void addUser(User user);
    public void updateUser(User user);
}

@Repository
public class UserDaoImpl implements UserDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public User getUserById(int id) {
        String sql = "SELECT * FROM user WHERE id = ?";
        RowMapper<User> rowMapper = new BeanPropertyRowMapper<>(User.class);
        User user = jdbcTemplate.queryForObject(sql, rowMapper, id);
        return user;
    }

    public User getUserByUsername(String username) {
        String sql = "SELECT * FROM user WHERE username = ?";
        RowMapper<User> rowMapper = new BeanPropertyRowMapper<>(User.class);
        User user = jdbcTemplate.queryForObject(sql, rowMapper, username);
        return user;
    }

    public void addUser(User user) {
        String sql = "INSERT INTO user(username, password) VALUES(?, ?)";
        jdbcTemplate.update(sql, user.getUsername(), user.getPassword());
    }

    public void updateUser(User user) {
        String sql = "UPDATE user SET username=?, password=? WHERE id=?";
        jdbcTemplate.update(sql, user.getUsername(), user.getPassword(), user.getId());
    }
}

5. 创建UserController类

创建UserController类，用于处理用户登录和注册的请求：

@Controller
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserDao userDao;

    @RequestMapping(value = "/login", method = RequestMethod.POST)
    public String login(String username, String password, Model model) {
        User user = userDao.getUserByUsername(username);
        if (user == null) {
            model.addAttribute("error", "用户不存在");
            return "login";
        } else if (!user.getPassword().equals(password)) {
            model.addAttribute("error", "密码错误");
            return "login";
        } else {
            model.addAttribute("user", user);
            return "home";
        }
    }

    @RequestMapping(value = "/register", method = RequestMethod.POST)
    public String register(User user, Model model) {
        User existUser = userDao.getUserByUsername(user.getUsername());
        if (existUser != null) {
            model.addAttribute("error", "用户名已存在");
            return "register";
        } else {
            userDao.addUser(user);
            return "redirect:/user/login";
        }
    }
}

6. 创建登录和注册页面

创建登录和注册页面，例如login.jsp和register.jsp：

<!-- login.jsp -->
<form action="${pageContext.request.contextPath}/user/login" method="post">
    <label for="username">用户名：</label>
    <input type="text" name="username" required="required" /><br />
    <label for="password">密码：</label>
    <input type="password" name="password" required="required" /><br />
    <button type="submit">登录</button>
</form>

<!-- register.jsp -->
<form action="${pageContext.request.contextPath}/user/register" method="post">
    <label for="username">用户名：</label>
    <input type="text" name="username" required="required" /><br />
    <label for="password">密码：</label>
    <input type="password" name="password" required="required" /><br />
    <button type="submit">注册</button>
</form>

以上就是使用SSM框架实现用户登录和注册的基本步骤，您可以根据需要进行修改和扩展。