Service层介绍
[toc]
和DAO的区别
数据层单纯的操作数据库 业务层将业务逻辑转化成代码
举例:
| 层 | 注册 | 登录 |
|---|---|---|
| DAO | 单纯加入数据库 | 查询是否存在 |
| Service | 账号不允许重复 | 超过五次禁止登陆 |
书写方式
在实体类的基础上, 创建业务接口类, 然后创建业务类实现接口类的方法(和DAO的单元测试类似, 不过是可以有返回值和参数的). 最后对业务类创建单元测试类进行测试.
实体类 -> 接口类 -> 业务类 -> 单元测试
注: 此处反复利用了DAO层的 UserMapper 类来封装底层结构
实体类
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// 实体类,在之前的基础上改成了MP模式,书写更加简单那
// com.neuedu/entity/User.java
@TableName("user")
@Data
public class User {
@TableId(value = "id", type = IdType.AUTO)
private Integer id;
private String username;
private String password;
private String birthday;
private String sex;
private String address;
}
接口类
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// 定义业务方法
// com.neuedu/service/UserService.java
public interface UserService {
// boolean login(String username,String pwd);
boolean login(User user);
// 参数封装为对象之后,如果在user加字段,就可以直接改变,不需要改变参数
boolean register(User user);
}
业务类
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// com.neuedu/service/impl/UserServiceImpl/UserServiceImpl.java
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserMapper userMapper;
public HashMap<String, Integer> userLoginCount = new HashMap<>();
@Override
public boolean login(User user) {
QueryWrapper queryWrapper = new QueryWrapper();
String userName = user.getUsername();
queryWrapper.eq("username", userName);
List<User> list = userMapper.selectList(queryWrapper);
if (list.size() > 0) {
String password = list.get(0).getPassword();
if (password.equals(user.getPassword())) {
return true;
} else {
int count = 0;
if (userLoginCount.containsKey(userName)) {
count = userLoginCount.get(userName);
}
if (count >= 5) {
return false;
} else {
userLoginCount.put(userName, count + 1);
return true;
}
}
}
return false;
}
@Override
public boolean register(User user) {
// 先查询,再插入
QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("username", user.getUsername());
List<User> list = userMapper.selectList(queryWrapper);
if (list.size() > 0) {
return false;
}
userMapper.insert(user);
return true;
}
}
单元测试
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// com.neuedu/service/impl/UserServiceImplTest.java
@SpringBootTest
@Slf4j
class UserServiceImplTest {
@Autowired
private UserService userService;
@Autowired
private PaginationInterceptor paginationInterceptor;
@Test
void testConfig() {
Assert.assertNotNull(paginationInterceptor);
}
@Test
void login() {
log.info(userService + "");
User user = new User();
user.setUsername("张三");
boolean bool = userService.login(user);
Assert.assertTrue(bool);
}
@Test
void login6times() {
for (int i = 0; i < 6; ++i) {
log.info(userService + "");
User user = new User();
user.setUsername("张三");
boolean bool = userService.login(user);
log.info(i + " " + bool);
if (i == 5) {
Assert.assertFalse(bool);
}
}
}
@Test
void register() {
log.info(userService + "");
User user = new User();
user.setUsername("zhangsan");
boolean bool = userService.register(user);
// 检查返回值
Assert.assertTrue(bool);
}
}
