@Configuration注解的proxyBeanMethods属性的作用

本文主要是介绍@Configuration注解的proxyBeanMethods属性的作用，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、proxybeanMethods源码注释

    /*** Specify whether {@code @Bean} methods should get proxied in order to enforce* bean lifecycle behavior, e.g. to return shared singleton bean instances even* in case of direct {@code @Bean} method calls in user code. This feature* requires method interception, implemented through a runtime-generated CGLIB* subclass which comes with limitations such as the configuration class and* its methods not being allowed to declare {@code final}.* <p>The default is {@code true}, allowing for 'inter-bean references' via direct* method calls within the configuration class as well as for external calls to* this configuration's {@code @Bean} methods, e.g. from another configuration class.* If this is not needed since each of this particular configuration's {@code @Bean}* methods is self-contained and designed as a plain factory method for container use,* switch this flag to {@code false} in order to avoid CGLIB subclass processing.* <p>Turning off bean method interception effectively processes {@code @Bean}* methods individually like when declared on non-{@code @Configuration} classes,* a.k.a. "@Bean Lite Mode" (see {@link Bean @Bean's javadoc}). It is therefore* behaviorally equivalent to removing the {@code @Configuration} stereotype.* @since 5.2*/boolean proxyBeanMethods() default true;

指定是否@Bean方法应以执行bean的生命周期行为，例如，即使在直接的情况下返回共享单bean实例获得代理@Bean用户代码的方法调用。该功能要求的方法的拦截，通过它配有限制的运行时生成的CGLIB子类实现如配置类及其方法不被允许声明final 。
默认为true ，允许通过配置类内部以及外部调用该配置的直接方法调用“bean间引用” @Bean方法，例如从另一个配置类。如果这不是因为每个的这种特定配置的需要@Bean方法是自包含的并且设计为用于容器使用一个普通的工厂的方法，切换该标志来false以免CGLIB子类的处理。
关闭bean方法拦截有效地处理@Bean方法来单独像非申报时@Configuration类，又名“@Bean精简版模式”（见@Bean's javadoc ）。因此，它是行为上等同于除去@Configuration铅板。从5.2版版本开始。

二、简单来说

注解的意思是proxyBeanMethods配置类是用来指定@Bean注解标注的方法是否使用代理，

2.1 默认是true使用代理，直接从IOC容器之中取得对象；

package com.tree.securitydemo.config;import lombok.extern.java.Log;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** proxybeanMethods** @author zhong* @create 2020-10-11 12:14* @contact 1478168700@qq.com**/
@Configuration(proxyBeanMethods = true)
@Log
public class ProxyBeanMethodsConfig {@BeanMyBean1 myBean1(){MyBean1 myBean1 = new MyBean1();//调用myBean2()方法myBean1.setMyBean2(myBean2());return myBean1;}@BeanMyBean2 myBean2(){log.info("myBean2()被调用啦");MyBean2 myBean2 = new MyBean2();log.info(myBean2.toString());return myBean2;}
}
class MyBean1{private MyBean2 myBean2;public MyBean2 getMyBean2() {return myBean2;}public void setMyBean2(MyBean2 myBean2) {this.myBean2 = myBean2;}
}
class MyBean2{public MyBean2(){}}

此时控制台只会调用一次myBean2P()方法

2.2 如果设置为false,也就是不使用注解，每次调用@Bean标注的方法获取到的对象和IOC容器中的都不一样，是一个新的对象，所以我们可以将此属性设置为false来提高性能。

package com.tree.securitydemo.config;import lombok.extern.java.Log;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** proxybeanMethods** @author zhong* @create 2020-10-11 12:14* @contact 1478168700@qq.com**/
@Configuration(proxyBeanMethods = false)
@Log
public class ProxyBeanMethodsConfig {@BeanMyBean1 myBean1(){MyBean1 myBean1 = new MyBean1();//调用myBean2()方法myBean1.setMyBean2(myBean2());return myBean1;}@BeanMyBean2 myBean2(){log.info("myBean2()被调用啦");MyBean2 myBean2 = new MyBean2();log.info(myBean2.toString());return myBean2;}
}
class MyBean1{private MyBean2 myBean2;public MyBean2 getMyBean2() {return myBean2;}public void setMyBean2(MyBean2 myBean2) {this.myBean2 = myBean2;}
}
class MyBean2{public MyBean2(){}}

此时控制台调用了两次myBean2()