package com.ajjpj.amapper.javabean.builder.qualifier;
import com.ajjpj.amapper.core.tpe.AQualifier;
import com.ajjpj.amapper.javabean.annotation.AQualifierAnnotation;
import com.ajjpj.amapper.util.coll.AHashMap;
import com.ajjpj.amapper.util.coll.AMap;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* @author arno
*/
public class AAnnotationBasedQualifierExtractor implements AQualifierExtractor {
public static final AAnnotationBasedQualifierExtractor INSTANCE = new AAnnotationBasedQualifierExtractor();
private static final QualAnnotDesc NO_QUAL_ANNOT = new QualAnnotDesc(false, null, null);
private static class QualAnnotDesc {
public final boolean isQualifier;
public final String name;
public final Method valueGetter;
private QualAnnotDesc(boolean isQualifier, String name, Method valueGetter) {
this.isQualifier = isQualifier;
this.name = name;
this.valueGetter = valueGetter;
}
}
private final Map<Class<?>, QualAnnotDesc> cache = new ConcurrentHashMap<Class<?>, QualAnnotDesc>();
@Override
public AQualifier extract(AnnotatedElement el) throws Exception {
AMap<String, String> map = AHashMap.empty();
for(Annotation a: el.getAnnotations()) {
final QualAnnotDesc desc = isQualifierAnnotation(a.annotationType());
if(desc.isQualifier) {
final Object valueRaw = desc.valueGetter != null ? desc.valueGetter.invoke(a) : null;
final String value = valueRaw != null ? valueRaw.toString() : null;
map = map.updated(desc.name, value);
}
}
return AQualifier.create(map);
}
private QualAnnotDesc isQualifierAnnotation(Class<?> annotClass) {
final QualAnnotDesc cached = cache.get(annotClass);
if(cached != null) {
return cached;
}
QualAnnotDesc result;
final AQualifierAnnotation annot = annotClass.getAnnotation(AQualifierAnnotation.class);
if (annot == null) {
result = NO_QUAL_ANNOT;
}
else {
final String name = annot.name();
result = new QualAnnotDesc(true, name, valueGetter(annotClass));
}
cache.put(annotClass, result);
return result;
}
private Method valueGetter(Class<?> annotClass) {
try {
return annotClass.getMethod("value");
} catch (NoSuchMethodException e) {
return null;
}
}
}