spring @condition 注解

spring @condition注解是用来在不同条件下注入不同实现的

demo如下:

package com.foreveross.service.weixin.test.condition;import org.springframework.context.annotation.Condition;import org.springframework.context.annotation.ConditionContext;import org.springframework.core.type.AnnotatedTypeMetadata;/** *  * windows下的环境 * */public class WindowsCondition implements Condition{@Overridepublic boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {retu context.getEnvironment().getProperty("os.name").contains("Windows");}}

package com.foreveross.service.weixin.test.condition;import org.springframework.context.annotation.Condition;import org.springframework.context.annotation.ConditionContext;import org.springframework.core.type.AnnotatedTypeMetadata;public class LinuxCondition implements Condition{@Overridepublic boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {retu context.getEnvironment().getProperty("os.name").contains("Linux");}}

package com.foreveross.service.weixin.test.condition;public interface ListService {String showListCmd();}

package com.foreveross.service.weixin.test.condition;import org.springframework.stereotype.Service;@Servicepublic class LinuxService implements ListService {public String showListCmd(){retu "ls";}}

package com.foreveross.service.weixin.test.condition;import org.springframework.stereotype.Service;@Servicepublic class WindowsService implements ListService{public String showListCmd(){retu "dir";}}

package com.foreveross.service.weixin.test.condition;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Conditional;import org.springframework.context.annotation.Configuration;@Configurationpublic class MyConfiguration {@Bean(name = "service")@Conditional(WindowsCondition.class)public ListService windowsService() {retu new WindowsService();}@Bean(name = "service")@Conditional(LinuxCondition.class)public ListService linuxEmailerService() {retu new LinuxService();}}

package com.foreveross.service.weixin.test.condition;import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class Test {public static void main(String[] args) {AnnotationConfigApplicationContext context=new AnnotationConfigApplicationContext(MyConfiguration.class);ListService service= context.getBean(ListService.class);System.out.println("操作符为:"+service.showListCmd()+",系统为:"+context.getEnvironment().getProperty("os.name"));context.close();}}