org.springframework.web.method.ControllerAdviceBean#isApplicableToBeanType(@Nullable Class<?> beanType)
判断当前类是否被ControllerAdviceBean修饰，判断依据位 ControllerAdviceBean上设置的注解@ControllerAdvice内的参数
package org.springframework.web.bind.annotation;
import java.lang.annotation.Annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.springframework.core.annotation.AliasFor;
import org.springframework.stereotype.Component;
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface ControllerAdvice {
@AliasFor("basePackages")
String[] value() default {};
@AliasFor("value")
String[] basePackages() default {};
Class<?>[] basePackageClasses() default {};
Class<?>[] assignableTypes() default {};
Class<? extends Annotation>[] annotations() default {};
}
其内部使用 HandlerTypePredicate beanTypePredicate 进行判断，如果@ControllerAdvice注解内无参数 则可以修饰所有类。
由该段代码判断：
ControllerAdvice annotation = (beanType != null ?
AnnotatedElementUtils.findMergedAnnotation(beanType, ControllerAdvice.class) : null);
if (annotation != null) {
this.beanTypePredicate = HandlerTypePredicate.builder()
.basePackage(annotation.basePackages())
.basePackageClass(annotation.basePackageClasses())
.assignableType(annotation.assignableTypes())
.annotation(annotation.annotations())
.build();
}
else {
this.beanTypePredicate = HandlerTypePredicate.forAnyHandlerType();
}
HandlerTypePredicate.forAnyHandlerType(); 改方法实现如下：
return new HandlerTypePredicate(Collections.emptySet(), Collections.emptyList(), Collections.emptyList());
=====
实际会调用org.springframework.web.method.HandlerTypePredicate#test
if (!hasSelectors()) {
return true;
}
org.springframework.web.method.HandlerTypePredicate#hasSelectors
private boolean hasSelectors() {
return (!this.basePackages.isEmpty() || !this.assignableTypes.isEmpty() || !this.annotations.isEmpty());
}
org.springframework.web.method.ControllerAdviceBean#isApplicableToBeanType 作用