Java学习 --- @Configuration注解

一、@Configuration 与@Bean注解

@Configuration //这个类就是配置类相当于配置文件
public class MyConfig {
    @Bean
    public User user(){
        return new User("老王",25);
    }
    @Bean("pet") //相当于组件
    public Pet pet(){
        return new Pet("小白",1);
    }
}

 二、加载的组件相当于单实例

@SpringBootApplication
public class MyApplicataion {
    public static void main(String[] args) {
        ConfigurableApplicationContext run = SpringApplication.run(MyApplicataion.class, args);
        String[] names = run.getBeanDefinitionNames();
        for (String name: names) {
            System.out.println(name);
        }
        Pet pet1 = run.getBean("pet", Pet.class);
        Pet pet2 = run.getBean("pet", Pet.class);
        System.out.println("pet1 与 pet2:"+ (pet1 == pet2));
    }
 
}

 三、配置类本身是组件

@SpringBootApplication
public class MyApplicataion {
    public static void main(String[] args) {
        ConfigurableApplicationContext run = SpringApplication.run(MyApplicataion.class, args);
        String[] names = run.getBeanDefinitionNames();
        for (String name: names) {
            System.out.println(name);
        }
        MyConfig bean = run.getBean(MyConfig.class);
        System.out.println(bean);
    }

四、@Configuration(proxyBeanMethods = true)

@Configuration(proxyBeanMethods = true) //这个类就是配置类相当于配置文件
public class MyConfig {
    @Bean
    public User user(){
        return new User("老王",25);
    }
    @Bean("pet") //相当于组件
    public Pet pet(){
        return new Pet("小白",1);
    }
}

---

原文链接：https://blog.csdn.net/qq_46093575/article/details/123719491