Spring中@Lazy注解的使用示例教程

@Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Lazy {
	/**
	 * Whether lazy initialization should occur.
	 */
	boolean value() default true;
}

@Data
@NoArgsConstructor
public class User {
    private String name;
    private String phone;
    private Integer age;
    private Person person;
    public User(String name, String phone, Integer age) {
        System.out.println("我User被初始化了.............");
        this.name = name;
        this.phone = phone;
        this.age = age;
    }
}

@Data
@NoArgsConstructor
public class Person {
    private String name;
    private String phone;
    private Integer age;
    private User user;
    public Person(String name, String phone, Integer age) {
        System.out.println("我Person被初始化了.............");
        this.name = name;
        this.phone = phone;
        this.age = age;
    }
}

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
    @Bean
    public User createUser() {
        return new User("韩宣生", "11111", 24);
    }
    @Bean
    @Lazy
    public Person createPerson() {
        return new Person("韩立", "11111", 24);
    }
}

@Component
public class PersonConfig {
    private UserConfig userConfig;
    public PersonConfig( UserConfig userConfig) {
        this.userConfig = userConfig;
        System.out.println("我是用户配置 PersonConfig");
    }
}

@Component
public class UserConfig {
    private PersonConfig personConfig;
    public UserConfig(PersonConfig personConfig) {
        this.personConfig = personConfig;
        System.out.println("我是用户配置 UserConfig");
    }
}

Description:
The dependencies of some of the beans in the application context form a cycle:

@Component
public class PersonConfig {
    private UserConfig userConfig;
    public PersonConfig(@Lazy UserConfig userConfig) {
        this.userConfig = userConfig;
        System.out.println("我是用户配置 PersonConfig");
    }
}