Spring源码分析(五)-注解@Conditional条件注册bean

学无止境 lv.1

发布时间：2022-12-05 20:22:06 281

相关标签： # java# spring# linux# 容器# 信息

Conditional条件注册bean

假设有这么一个场景，需要根据操作系统加载不同的实例

将IOC容器注册bean时, 当操作系统为WINDOWS时,注册caojiulu实例; 当操作系统为LINUX时, 注册hujinxiao实例,此时要用得@Conditional注解进行定制化条件选择注册bean

新建Cap5MainConfig.java

package com.caojiulu.cap5.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Conditional;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

import com.caojiulu.cap1.bean.Person;
import com.caojiulu.cap5.condition.LinuxCondition;
import com.caojiulu.cap5.condition.WinConditin;

@Configuration
public class Cap5MainConfig {

  @Conditional({WinConditin.class})
  @Bean
  public Person caojiulu(){
    return new Person("caojiulu",20);
  }
  @Conditional({LinuxCondition.class})
  @Bean
  public Person huinxiao(){
    return new Person("huinxiao",28);
  }
}

新建WinConditin.java

package com.caojiulu.cap5.condition;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.type.AnnotatedTypeMetadata;

public class WinConditin implements Condition{

  /**
   * ConditionContext :上下文环境
   * AnnotatedTypeMetadata ： 注释信息
   */
  public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
    //是否window系统
    
    //获取beanFactory
    ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
    //获取类加载器
    ResourceLoader resourceLoader = context.getResourceLoader();
    //获取环境信息
    Environment environment = context.getEnvironment();
    //获取bean定义的注册类
    BeanDefinitionRegistry registry = context.getRegistry();
    String property = environment.getProperty("os.name");
    if(property.contains("Windows")){
      return true;
    }
    return false;
  }

  
}

新建LinuxCondition.java

package com.caojiulu.cap5.condition;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.env.Environment;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.type.AnnotatedTypeMetadata;

public class LinuxCondition implements Condition{

  /**
   * ConditionContext :上下文环境
   * AnnotatedTypeMetadata ： 注释信息
   */
  public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
    //是否window系统
    
    //获取beanFactory
    ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
    //获取类加载器
    ResourceLoader resourceLoader = context.getResourceLoader();
    //获取环境信息
    Environment environment = context.getEnvironment();
    //获取bean定义的注册类
    BeanDefinitionRegistry registry = context.getRegistry();
    String property = environment.getProperty("os.name");
    if(property.contains("linux")){
      return true;
    }
    return false;
  }

  
}

测试类：

模拟linux环境：

Spring源码分析(五)-注解@Conditional条件注册bean_spring

Spring源码分析(五)-注解@Conditional条件注册bean_java_02

文章来源： https://blog.51cto.com/u_14906615/5899337

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