Package info. Cannot be modified using java 8 Java comments

I'm facing a problem. I have to modify the package information

package-info. java

@javax.xml.bind.annotation.XmlSchema(namespace = "http://some.url/soap/style/document_literal")
package org.example.wsdl.wsdl;

The following codes apply to 1.7 0_ forty-five

//          do not load any classes before,this Could break the following code.
            Class<?> pkgInfo = Class.forName("org.example.wsdl.package-info",true,NameSpaceModifier.class.getClassLoader());
            Field field = Class.class.getDeclaredField("annotations");
            field.setAccessible(true);

            final XmlSchema oldAnnotation = (XmlSchema) pkgInfo.getAnnotations()[0];
            logger.debug("Old Annotation namespace value was: " + oldAnnotation.namespace());
            XmlSchema newAnnotation = new XmlSchema() {

                @Override
                public XmlNs[] xmlns() {
                    return oldAnnotation.xmlns();
                }

                @Override
                public String namespace() {
                    return "newNs";
                }

                @Override
                public XmlNsForm elementFormDefault() {
                    return oldAnnotation.elementFormDefault();
                }

                @Override
                public XmlNsForm attributeFormDefault() {
                    return oldAnnotation.attributeFormDefault();
                }

                @Override
                public String location() {
                    return oldAnnotation.location();
                }

                @Override
                public Class<? extends Annotation> annotationType() {
                    return oldAnnotation.annotationType();
                }
            };

            @SuppressWarnings("unchecked")
            Map<Class<? extends Annotation>,Annotation> annotations = (Map<Class<? extends Annotation>,Annotation>) field.get(pkgInfo);
            annotations.put(XmlSchema.class,newAnnotation);

            XmlSchema modifiedAnnotation = (XmlSchema) pkgInfo.getAnnotations()[0];

Use 1.8 0_ 05 when compiling and executing the same code, I receive the following error message:

java.lang.NoSuchFieldException: annotations
    at java.lang.Class.getDeclaredField(Class.java:2057)

I know it's a Huck, at least it looks like a Huck But does Java 8 work as expected? How do I change the code that it uses with Java 8?

Javassist's answer is also very popular;)

Solution

Java 8 has changed the way annotations are stored internally Because you are using a malicious reflection hacker with hard coded field names, any Java update may re destroy your code

java. In lang.class:

/**
 * @since 1.5
 */
public Annotation[] getAnnotations() {
    return AnnotationParser.toArray(annotationData().annotations);
}

private volatile transient AnnotationData annotationData;

private AnnotationData annotationData() {
    while (true) { // retry loop
        AnnotationData annotationData = this.annotationData;
        int classredefinedCount = this.classredefinedCount;
        if (annotationData != null &&
            annotationData.redefinedCount == classredefinedCount) {
            return annotationData;
        }
        // null or stale annotationData -> optimistically create new instance
        AnnotationData newAnnotationData = createAnnotationData(classredefinedCount);
        // try to install it
        if (Atomic.casAnnotationData(this,annotationData,newAnnotationData)) {
            // successfully installed new AnnotationData
            return newAnnotationData;
        }
    }
}

private static class AnnotationData {
    final Map<Class<? extends Annotation>,Annotation> annotations;
    final Map<Class<? extends Annotation>,Annotation> declaredAnnotations;

    // Value of classredefinedCount when we created this AnnotationData instance
    final int redefinedCount;

    AnnotationData(Map<Class<? extends Annotation>,Annotation> annotations,Map<Class<? extends Annotation>,Annotation> declaredAnnotations,int redefinedCount) {
        this.annotations = annotations;
        this.declaredAnnotations = declaredAnnotations;
        this.redefinedCount = redefinedCount;
    }
}

I think you can use the new field values to fix your code temporarily A permanent fix is to change the annotation itself, not dynamically modify it at run time

Field annotationdatafield = Class.class.getDeclaredField("annotationData");
annotationdatafield.setAccessible(true);

Object annotationData = annotationdatafield.get(pkgInfo);

Field annotationsField = annotationData.getClass().getDeclaredField("annotations");
annotationsField.setAccessible(true);

Map<Class<? extends Annotation>,Annotation>) annotationsField
        .get(annotationData);
annotations.put(XmlSchema.class,newAnnotation);

XmlSchema modifiedAnnotation = (XmlSchema) pkgInfo.getAnnotations()[0];