Java注释处理器将忽略父类中的注释

Question

我有下面的课程。 两个注释（ AnnotA和AnnotB ），一个类' Child .java'（带有@AnnotA）和它的父类' Base .java'（带有@AnnotB）。

编译Child.java时，我的注释处理器会报告AnnotA，但不会报告在Base.java中找到的注释（ AnnotB ）。

AnnotA.java

import java.lang.annotation.*;
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE })
public @interface AnnotA
    {
    }

AnnotB.java

import java.lang.annotation.*;
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE })
public @interface AnnotB
    {
    }

Base.java

@AnnotB
public class Base
    {
    }

Child.java

@AnnotA
public class Child extends Base
    {
    }

MyProc.java

import javax.annotation.processing.*;
import java.lang.annotation.*;
import javax.lang.model.*;
import javax.lang.model.element.*;
import javax.tools.*;
import java.util.*;
import java.util.stream.*;

@SupportedSourceVersion(SourceVersion.RELEASE_8)
public class MyProc  extends AbstractProcessor
    {
    @Override
    public Set<String> getSupportedAnnotationTypes()  {
        final Set<String> set = new HashSet<>();
        set.add("AnnotA");
        set.add("AnnotB");
        return set;
        }
    @Override
    public boolean process(final Set<? extends TypeElement> annotations,
        final RoundEnvironment roundEnv
        ) {
        roundEnv.getElementsAnnotatedWith(AnnotA.class).stream().
            forEach(E->{System.err.println("AnnotA>>" + E + " "+ E.getAnnotation(AnnotA.class));});

        roundEnv.getElementsAnnotatedWith(AnnotB.class).stream().
            forEach(E->{System.err.println("AnnotB>>" + E + " "+ E.getAnnotation(AnnotB.class));});
        return true;
        }
    }

如您所见，这是编译过程及其输出，而Parent.java是Child.java的父级时，没有有关AnnotB的消息。

rm -rf tmp
mkdir -p tmp/META-INF/services
javac -d tmp MyProc.java
echo "MyProc" > tmp/META-INF/services/javax.annotation.processing.Processor
jar cvf myproc.jar -C tmp .
added manifest
ignoring entry META-INF/
adding: META-INF/services/(in = 0) (out= 0)(stored 0%)
adding: META-INF/services/javax.annotation.processing.Processor(in = 7) (out= 9)(deflated -28%)
adding: AnnotB.class(in = 363) (out= 221)(deflated 39%)
adding: MyProc.class(in = 2512) (out= 1118)(deflated 55%)
adding: AnnotA.class(in = 363) (out= 221)(deflated 39%)
##
mkdir -p tmp
javac -processorpath myproc.jar -d tmp Child.java
AnnotA>>Child @AnnotA()
warning: Implicitly compiled files were not subject to annotation processing.
  Use -implicit to specify a policy for implicit compilation.
1 warning
rm -rf tmp

此代码有什么问题？ 谢谢 。

Answer 1

使用@Inherited继承注释。

如何在Java中使用@inherited注释？