以SSM框架为基础的JAVA项目编写代码

好的，下面是一个基于SSM框架的Java项目的代码示例，供参考：

1. 实体类代码示例：

public class User {
    private int id;
    private String username;
    private String password;
    
    // 省略 getter 和 setter 方法
}

2. DAO层代码示例：

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

@Repository
public class UserDaoImpl implements UserDao {
    
    @Autowired
    private SqlSessionTemplate sqlSessionTemplate;
    
    public User getUserById(int id) {
        return sqlSessionTemplate.selectOne("getUserById", id);
    }

    public void addUser(User user) {
        sqlSessionTemplate.insert("addUser", user);
    }

    public void updateUser(User user) {
        sqlSessionTemplate.update("updateUser", user);
    }

    public void deleteUser(int id) {
        sqlSessionTemplate.delete("deleteUser", id);
    }
}

3. Service层代码示例：

public interface UserService {
    User getUserById(int id);
    void addUser(User user);
    void updateUser(User user);
    void deleteUser(int id);
}

@Service
public class UserServiceImpl implements UserService {
    
    @Autowired
    private UserDao userDao;
    
    public User getUserById(int id) {
        return userDao.getUserById(id);
    }

    public void addUser(User user) {
        userDao.addUser(user);
    }

    public void updateUser(User user) {
        userDao.updateUser(user);
    }

    public void deleteUser(int id) {
        userDao.deleteUser(id);
    }
}

4. Controller层代码示例：

@Controller
@RequestMapping("/user")
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @RequestMapping("/get/{id}")
    @ResponseBody
    public User getUserById(@PathVariable("id") int id) {
        return userService.getUserById(id);
    }

    @RequestMapping("/add")
    public String addUser(User user) {
        userService.addUser(user);
        return "redirect:/user/list";
    }

    @RequestMapping("/update")
    public String updateUser(User user) {
        userService.updateUser(user);
        return "redirect:/user/list";
    }

    @RequestMapping("/delete/{id}")
    public String deleteUser(@PathVariable("id") int id) {
        userService.deleteUser(id);
        return "redirect:/user/list";
    }
}

以上代码示例仅供参考，实际项目中可能需要根据具体需求进行调整和优化。