@order注解 解答

注解@Order或者接口Ordered的作用是定义Spring IOC容器中Bean的执行顺序的优先级，而不是定义Bean的加载顺序，Bean的加载顺序不受@Order或Ordered接口的影响；

注解源码解读：

@Retention(RetentionPolicy.RUNTIME) @Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD}) @Documented public @interface Order {  	/** 	 * 默认是最低优先级,值越小优先级越高 	 */ 	int value() default Ordered.LOWEST_PRECEDENCE;  }

示例代码:

package com.runlion.tms.admin.constant;  public class AService {  } package com.runlion.tms.admin.constant;  public class BService {  }

package com.runlion.tms.admin.constant;  import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.annotation.Order;  @Configuration @Order(2) public class AConfig {   @Bean   public AService AService() {     System.out.println("AService 加载了");     return new AService();   }  } package com.runlion.tms.admin.constant;  import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.annotation.Order;  @Configuration @Order(1) public class BConfig {   @Bean   public BService bService() {     System.out.println("BService 加载了");     return new BService();   } }

package com.runlion.tms.admin.constant;  import org.springframework.context.annotation.AnnotationConfigApplicationContext;  public class OrderMain {   public static void main(String[] args) {     AnnotationConfigApplicationContext context =         new AnnotationConfigApplicationContext("com.runlion.tms.admin.constant");   } }