JPA之@EnableJpaAuditing注解使用

@EnableScheduling
@EnableJpaAuditing //利用jpa可以给MySQL列属性自动赋值,例如一些创建时间，修改时间
@EnableEurekaClient
@SpringBootApplication
public class CouponTemplateApplication {
    public static void main(String[] args) {
        SpringApplication.run(CouponTemplateApplication.class, args);
    }
 /**
     * 测试中如果无法自动识别,可能是包路径的问题，采用手动声明bean的方式
     * @return
     */
    @Bean
    public UserAuditor setUserAuditorAware(){
        return new UserAuditor();
    }
}

@Data
@NoArgsConstructor
@AllArgsConstructor
@Entity  //实体类
@EntityListeners(AuditingEntityListener.class) //监听器，自动赋值创建时间
@Table(name = "coupon_template")
@JsonSerialize(using = CouponTemplateSerialize.class) //绑定自定义的序列化器
public class CouponTemplate implements Serializable {
    /** 自增主键 */
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id",nullable = false)
    @Basic //指定属于我们数据表的一个列，相反的@Transient，表示该列不属于数据表
    private Integer id;
    /** 是否是可用状态 */
    @Column(name = "available",nullable = false)
    private Boolean available;
    /** 是否过期 */
    @Column(name = "expired",nullable = false)
    private Boolean expired;
    /** 优惠券名称 */
    @Column(name = "name",nullable = false)
    private String name;
    /** 优惠券 logo */
    @Column(name = "logo",nullable = false)
    private String logo;
    /** 优惠券描述 */
    @Column(name = "intro",nullable = false)
    private String desc;
    
    /** 优惠券模板 创建时间
     *      使用@CreateDate注解在插入的时候，自动生成创建时间，与监听注解有关
     * */
    @CreatedDate
    @Column(name = "create_time",nullable = false)
    private Date createTime;
}

@Configuration
@Slf4j
public class UserAuditor implements AuditorAware<String> {
    /**
     * 获取当前创建或修改的用户
     * @return
     */
    @Override
    public Optional<String> getCurrentAuditor() {
        UserDetails user;
        try {
            user = (UserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
            return Optional.ofNullable(user.getUsername());
        }catch (Exception e){
            return Optional.empty();
        }
    }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.data.domain.AuditorAware;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import java.util.Optional;
/**
 *  使用@CreatedBy或@LastModifiedBy 则必须实现AuditorAware接口重写getCurrentAuditor方法
 * 在定义使用@CreatedBy或@LastModifiedBy时，属性类型必须与AuditorAware接口的泛型类型相同
 */
@Configuration
public class SpringSecurityAuditorAware  implements AuditorAware<String> {
    @Override
    public Optional<String> getCurrentAuditor() {
        UserDetails userDetails;
        try {
            userDetails =  (UserDetails)SecurityContextHolder.getContext().getAuthentication().getPrincipal();
            return Optional.ofNullable(userDetails.getUsername());
        }catch (Exception e){
            return Optional.empty();
        }
    }