import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.io.Serializable;

@Entity
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "src.User[ id=" + id + " ]";
    }
}

import java.util.List;

public interface UserDao {

    public List<User> getAllUsers();

}

import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
@Component
public class UserDaoImpl implements UserDao {
    @Override
    public List<User> getAllUsers() {
        return null;
    }
}

public class UserProvider {

// здесь будут разные методы, возвращающие листы данных по тем или иным параметрам.

}

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
public class UserController {

    private static final Logger log = Logger.getLogger(UserController.class);
    private UserDao userDao;

    @Autowired
    public UserController(UserDao userDao) {
        this.userDao = userDao;
    }

    @RequestMapping(value = "/users", method = RequestMethod.GET)
    @ResponseBody
    public List<User> getAllUsers() {
//        List<User> usersList =
        return null;
    }
}