我已经阅读了有关DAO类和Service类的信息,但我不了解它们的用途。
我已经在Spring和Hibernate的Maven中启动了一个项目,直到现在,我还在servlet.xml中添加了hibernate的配置:
<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
<property name="annotatedClasses">
<list>
<value>com.fabbydesign.model.Useradmin</value>
</list>
</property>
</bean>
控制器登录的方法是这样的:
@RequestMapping(value = "/do.html", method = RequestMethod.POST)
public String doLogin(@Valid @ModelAttribute("userLogin") LoginForm lf, BindingResult bindingResult, Map<String, Object> model, HttpServletRequest request){
//bindingResult.rejectValue("username", "label.title"); - to add new message error
logger.trace("showLogin - post");
//check fields if the filds are filled and respects the size from beans
if(bindingResult.hasErrors())
return "login";
boolean userExists = loginService.checkLogin(lf.getUsername(), lf.getPassword());
if(!userExists){
bindingResult.rejectValue("username", "login.username.wrongUserOrPassword");
return "login";
}
else{//set session
request.getSession().setAttribute(adminSesName, true);
}
return "redirect:/admin/dashboard.html";
}
loginServiceImpl:
@Service("loginService")
公共类LoginServiceImpl实现LoginService {
@Autowired
private LoginDAO loginDAO;
public void setLoginDAO(LoginDAO loginDAO) {
this.loginDAO = loginDAO;
}
public Boolean checkLogin(String userName, String userPassword) {
return loginDAO.checkLogin(userName, userPassword);
}
和loginDAOimpl:
@Repository("loginDAO")
公共类LoginDAOImpl实现LoginDAO {
@Resource(name = "sessionFactory")
protected SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
protected Session getSession() {
return sessionFactory.openSession();
}
final static Logger logger = Logger.getLogger(LoginDAOImpl.class);
public boolean checkLogin(String username, String password) {
Boolean userFound = false;
Session session = sessionFactory.openSession();
String sql = "from Useradmin where username = ?";
Query<?> query = session.createQuery(sql);
query.setParameter(0, username);
List<?> list = query.list();
if ((list != null) && (list.size() == 1)) {
Useradmin ua = (Useradmin) list.get(0);
if (BCrypt.checkpw(password, ua.getPassword())) {
userFound = true;
}
}
return userFound;
}
那么,我应该在服务类和DAO类中写什么?
我了解的是,用于处理数据库中数据的代码需要保留在DAO类中,但是服务类却适用于什么?
谢谢!
最佳答案
您可以参考以下简单示例:
1. PersonDao
仅关心数据库操作。
package com.pechen.dao;
import java.util.List;
import com.pechen.entity.Person;
public interface PersonDao {
public void save(Person p);
public List<Person> list();
}
2.
PersonDaoImpl
是实现。package com.pechen.dao;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.springframework.beans.factory.annotation.Autowired;
import com.pechen.entity.Person;
public class PersonDaoImpl implements PersonDao {
@Autowired
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public void save(Person p) {
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
session.save(p);
tx.commit();
session.close();
}
@SuppressWarnings("unchecked")
public List<Person> list() {
Session session = sessionFactory.openSession();
List<Person> rst = session.createQuery("from person").getResultList();
session.close();
return rst;
}
}
3.
PersonService
关心业务逻辑,您可以在数据库操作之前做任何想做的事情。package com.pechen.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import com.pechen.dao.PersonDao;
import com.pechen.dao.PersonDaoImpl;
import com.pechen.entity.Person;
public class PersonService {
@Autowired
private PersonDao personDao;
public void setPersonDao(PersonDaoImpl personImpl) {
this.personDao = personImpl;
}
public void savePerson(Person person) {
// other business logic
this.personDao.save(person);
System.out.println("Save person successfully: " + person);
}
public List<Person> getPersons() {
// other business logic
return this.personDao.list();
}
}
关于java - 有关如何使用DAO类和Service类,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/41585560/