/**
* Simple facade for accessing class metadata,
* as read by an ASM {@link org.springframework.asm.ClassReader}.
*
* @author Juergen Hoeller
* @since 2.5
*/
public interface MetadataReader {
/**
* Return the resource reference for the class file.
*/
Resource getResource();
/**
* Read basic class metadata for the underlying class.
*/
ClassMetadata getClassMetadata();
/**
* Read full annotation metadata for the underlying class,
* including metadata for annotated methods.
*/
AnnotationMetadata getAnnotationMetadata();
}
SimpleMetadataReader
/** 把resource通过asm读取出来信息
* {@link MetadataReader} implementation based on an ASM
* {@link org.springframework.asm.ClassReader}.
*
* @author Juergen Hoeller
* @author Costin Leau
* @since 2.5
*/
final class SimpleMetadataReader implements MetadataReader {
private static final int PARSING_OPTIONS = ClassReader.SKIP_DEBUG
| ClassReader.SKIP_CODE | ClassReader.SKIP_FRAMES;
private final Resource resource;
private final AnnotationMetadata annotationMetadata;
SimpleMetadataReader(Resource resource, @Nullable ClassLoader classLoader) throws IOException {
SimpleAnnotationMetadataReadingVisitor visitor = new SimpleAnnotationMetadataReadingVisitor(classLoader);
getClassReader(resource).accept(visitor, PARSING_OPTIONS);
this.resource = resource;
this.annotationMetadata = visitor.getMetadata();
}
private static ClassReader getClassReader(Resource resource) throws IOException {
try (InputStream is = resource.getInputStream()) {
try {
return new ClassReader(is);
}
catch (IllegalArgumentException ex) {
throw new NestedIOException("ASM ClassReader failed to parse class file - " +
"probably due to a new Java class file version that isn't supported yet: " + resource, ex);
}
}
}
@Override
public Resource getResource() {
return this.resource;
}
@Override
public ClassMetadata getClassMetadata() {
return this.annotationMetadata;
}
@Override
public AnnotationMetadata getAnnotationMetadata() {
return this.annotationMetadata;
}
}