注解 @Resource 和 @Autowire

素颜马尾好姑娘i 2022-10-25 15:27 289阅读 0赞

@Autowire

*  作用：可以对类成员变量，方法以及构造函数进行标注，让spring完成bean自动装配（spring通过依赖注入创建实例）的工作。
 *      @Target({ElementType.CONSTRUCTOR, ElementType.METHOD, ElementType.PARAMETER, ElementType.FIELD, ElementType.ANNOTATION_TYPE})
        @Retention(RetentionPolicy.RUNTIME)
        @Documented
        //java项目www.fhadmin.org
        public @interface Autowired {
        
        	/**
        	 * Declares whether the annotated dependency is required.
        	 * <p>Defaults to {@code true}.
        	 */
        	boolean required() default true;
        
        }
    
    使用：
 *      //java项目www.fhadmin.org
        public class ConditionTitleServiceImpl implements IConditionTitleService {
         
         	//创建类的实例，无需new对象
            @Autowired
            private IDataResourceDao iDataResourceDao;
            
            //set方法使用
            private People people;
            @Autowired
            public void setPeople(People people){
        		this.people = people;
        	}
            
            //构造法方法的使用
            private People people;
            @Autowired
            public ConditionTitleServiceImpl(People people){
        		this.people = people;
        	}
        	……
        }
    
    @Resource
 *  作用：按照名字进行匹配，如果没有找到同名bean，则按照类型进行匹配，最终实现让spring完成bean自动装配（spring通过依赖注入创建实例）的工作。
 *      @Target({TYPE, FIELD, METHOD})
        @Retention(RUNTIME)
        @Repeatable(Resources.class)
        public @interface Resource {
          ……
        }
    
    使用
 *      //java项目www.fhadmin.org
        public class ConditionTitleServiceImpl implements IConditionTitleService {
            @Resource
            private IConditionTitleDao iConditionTitleDao;
        	……
        }
    
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