Lombok使用(二)

• Data

@Data  // 相当于 @getter  @setter  @ToString  @EqualsAndHashCode，但需要所有属性的值相同才是同一个对象
@EqualsAndHashCode(of = {"id"})
public class UserInfoData {
    private Long id;
    private String name;
    private String phone;
    private Date birthDay;
    private String address;
}      

• Accessors

@Accessors(
//        chain = true, // 链式编程
        fluent = true
)
public class UserInfoAccessors {
    private Long id;
    private String name;
    private String phone;
    private Date birthDay;
    private String address;
}      

• 测试



• Builder

@Builder
public class User {
    private Long id;
    private String name;
    private String phone;
    private Date birthDay;
    private String address;
}      

• 查看编译后的类

public class User {
    private Long id;
    private String name;
    private String phone;
    private Date birthDay;
    private String address;

    User(Long id, String name, String phone, Date birthDay, String address) {
        this.id = id;
        this.name = name;
        this.phone = phone;
        this.birthDay = birthDay;
        this.address = address;
    }

    public static User.UserBuilder builder() {
        return new User.UserBuilder();
    }

    public static class UserBuilder {
        private Long id;
        private String name;
        private String phone;
        private Date birthDay;
        private String address;

        UserBuilder() {
        }

        public User.UserBuilder id(Long id) {
            this.id = id;
            return this;
        }

        public User.UserBuilder name(String name) {
            this.name = name;
            return this;
        }

        public User.UserBuilder phone(String phone) {
            this.phone = phone;
            return this;
        }

        public User.UserBuilder birthDay(Date birthDay) {
            this.birthDay = birthDay;
            return this;
        }

        public User.UserBuilder address(String address) {
            this.address = address;
            return this;
        }

        public User build() {
            return new User(this.id, this.name, this.phone, this.birthDay, this.address);
        }

        public String toString() {
            return "User.UserBuilder(id=" + this.id + ", name=" + this.name + ", phone=" + this.phone + ", birthDay=" + this.birthDay + ", address=" + this.address + ")";
        }
    }
}      

• 测试

public class Test {
    public static void main(String[] args) {
        User.UserBuilder builder = User.builder();
        User user = builder.id(1L).build();
        System.out.print(user);
    }
}      

• 日志

# 导入依赖
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>1.2.3</version>
    </dependency>

# 写法1
public class UserInfoService {
    private static final Logger LOGGER = LoggerFactory.getLogger(UserInfoService.class);
    public List<UserInfo> getAll() {
        LOGGER.info("进入getAll方法");
        return new ArrayList<>();
    }
}

# 写法2
@Slf4j // 专门针对项目里面使用的是slf4j
public class UserInfoService {
    public List<UserInfo> getAll() {
        log.info("进入getAll方法");
        return new ArrayList<>();
    }
}      

• 其他

@Log @Log4j @Log4j2      

• 原理

jsr	描述	相关实现
jsr107	缓存规范	spring基于此实现的缓存体系
jsr250	java平台Common Annotations 如@PostConstruct	spring
jsr269	Pluggable Annotation Processing API	lombok,mapstruct
jsr303,jsr349,jsr380	bean validation