Springboot常用注解之@Inherited和@interface

1. @Inherited：允许子类继承父类的注解，仅限于类注解有用，对于方法和属性无效。 

   测试元注解

   1.1 包含@Inherited注解

[code]@Documented
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface InheritedTrue {
String value();
}

  1.2 不包含@Inherited注解

[code]@Documented
@Retention(RetentionPolicy.RUNTIME)
public @interface InheritedFalse {
String value();
}

1.3 测试父类

[code]@InheritedTrue("InheritedTrue class")
@InheritedFalse("InheritedFalse class")
public class InheritedParent {

@InheritedTrue("InheritedTrue method")
@InheritedFalse("InheritedFalse method")
public void methodTest(){ }

@InheritedTrue("InheritedTrue no override method")
@InheritedFalse("InheritedFalse no override method")
public void methodInherttTest(){ }

@InheritedTrue("InheritedTrue field")
@InheritedFalse("InheritedFalse field")
public String stringTest;
}

   1.4 测试子类

[code]public class InheritedChild extends InheritedParent{

@Override
public void methodTest(){}
}

  1.5  单元测试父类

[code]@RunWith(SpringRunner.class)
@SpringBootTest
public class WalletTests {

private Logger logger = LoggerFactory.getLogger(WalletTests.class);

@Before
public void init() {
logger.info("开始测试-----------------");
}

@After
public void after() {
logger.info("测试结束-----------------");
}
}

 1.6 单元测试

[code]public class InheritedTest extends WalletTests {

private Logger logger = LoggerFactory.getLogger(InheritedTest.class);

@Test
public void InheritTest() throws NoSuchMethodException, NoSuchFieldException {
Class<InheritedChild> child = InheritedChild.class;
logger.info("对类进行测试");
if(child.isAnnotationPresent(InheritedTrue.class)){
logger.info(child.getAnnotation(InheritedTrue.class).value());
}
if(child.isAnnotationPresent(InheritedFalse.class)){
logger.info(child.getAnnotation(InheritedFalse.class).value());
}

logger.info("对重写方法进行测试");
Method method = child.getMethod("methodTest", null);
if(method.isAnnotationPresent(InheritedTrue.class)){
logger.info(method.getAnnotation(InheritedTrue.class).value());
}
if(method.isAnnotationPresent(InheritedFalse.class)){
logger.info(method.getAnnotation(InheritedFalse.class).value());
}

logger.info("对继承方法进行测试");
Method methodInherit = child.getMethod("methodInherttTest", null);
if(methodInherit.isAnnotationPresent(InheritedTrue.class)){
logger.info(methodInherit.getAnnotation(InheritedTrue.class).value());
}
if(methodInherit.isAnnotationPresent(InheritedFalse.class)){
logger.info(methodInherit.getAnnotation(InheritedFalse.class).value());
}

logger.info("对属性进行测试");
Field field = child.getField("stringTest");
if(field.isAnnotationPresent(InheritedTrue.class)){
logger.info(field.getAnnotation(InheritedTrue.class).value());
}
if(field.isAnnotationPresent(InheritedFalse.class)){
logger.info(field.getAnnotation(InheritedFalse.class).value());
}
}
}

1.7 测试结果

     可以看出只对类的继承有用，对于方法的重写和继承以及属性无效。

 2.@Interface

    自定义注释类型。java用  @interface Annotation{ } 定义一个注解 @Annotation，一个注解是一个类。

[code]@Documented
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface InterfaceTest {
String value() default "InterfaceTest";
}