如何强制Java子类定义注释？

Question

如果一个类定义了一个注释,是否有可能强制其子类定义相同的注释？

例如,我们有一个简单的类/子类对,它们共享@Author @interface. 我想要做的是强制每个进一步的子类来定义相同的@Author注释,从而防止出现在RuntimeException某个地方.

TestClass.java:

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@interface Author { String name(); }

@Author( name = "foo" )
public abstract class TestClass
{
    public static String getInfo( Class<? extends TestClass> c )
    {
        return c.getAnnotation( Author.class ).name();
    }

    public static void main( String[] args )
    {
        System.out.println( "The test class was written by "
                        + getInfo( TestClass.class ) );
        System.out.println( "The test subclass was written by " 
                        + getInfo( TestSubClass.class ) );
    }
}

TestSubClass.java:

@Author( name = "bar" )
public abstract class TestSubClass extends TestClass {}

我知道我可以在运行时枚举所有注释并检查缺失@Author,但我真的很想在编译时执行此操作,如果可能的话.

Answer 1

您可以在编译时使用 JSR 269 来做到这一点。请参阅： http: //today.java.net/pub/a/today/2006/06/29/validate-java-ee-annotations-with-annotation-processors.html#pluggable-annotation-processing-api

编辑2020-09-20：链接已死，存档版本在这里：https://web.archive.org/web/20150516080739/http ://today.java.net/pub/a/today/2006/06/29 /validate-java-ee-annotations-with-annotation-processors.html