Condition机遇条件创建bean

1. bean接口

   public interface EncodingConvert {
   }

    

2. 实现类

   public class UTF8EncodingConvert implements EncodingConvert {
   }

   public class GBKEncodingConvert implements EncodingConvert {
   }

    

3. Condition实现

   public class GBKCondition implements Condition {
       @Override
       public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata annotatedTypeMetadata) {
           String property = System.getProperty("file.encoding");
           return "GBK".equalsIgnoreCase(property);
       }
   }

   public class UTF8Condition implements Condition {
       @Override
       public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata annotatedTypeMetadata) {
           String property = System.getProperty("file.encoding");
           return "UTF-8".equalsIgnoreCase(property);
       }
   }

    

4.  

   配置类

   @SpringBootConfiguration
   public class EncodingConfiguration {
       @Bean
       @Conditional(UTF8Condition.class)
       public EncodingConvert getUTF8Encoding(){
           return new UTF8EncodingConvert();
       }
       @Bean
       @Conditional(GBKCondition.class)
       public EncodingConvert getGBKEncoding(){
           return new GBKEncodingConvert();
       }
   }

5. 启动类

   @SpringBootApplication
   public class SpringbootApplication {
   
   	public static void main(String[] args) {
   		ConfigurableApplicationContext context = SpringApplication.run(SpringbootApplication.class, args);
   		System.out.println(System.getProperty("file.encoding"));
   		System.out.println(context.getBeansOfType(EncodingConvert.class));
   	}
   
   }

    

6.  

   启动时设置参数

   运行结果