org.apache.tika.parser.image.MetadataFields Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tika.parser.image;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashSet;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.Property;
import org.apache.tika.metadata.TikaCoreProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Knowns about all declared {@link Metadata} fields.
* Didn't find this functionality anywhere so it was added for
* ImageMetadataExtractor, but it can be generalized.
*/
public abstract class MetadataFields {
private static final Logger LOG = LoggerFactory.getLogger(MetadataFields.class);
private static HashSet known;
static {
known = new HashSet();
setKnownForClass(TikaCoreProperties.class);
setKnownForClass(Metadata.class);
}
private static void setKnownForClass(Class clazz) {
Field[] fields = clazz.getFields();
for (Field f : fields) {
int mod = f.getModifiers();
if (Modifier.isPublic(mod) && Modifier.isStatic(mod) && Modifier.isFinal(mod)) {
Class c = f.getType();
if (String.class.equals(c)) {
try {
String p = (String) f.get(null);
if (p != null) {
known.add(p);
}
} catch (IllegalArgumentException e) {
LOG.warn("Illegal argument in field", e);
} catch (IllegalAccessException e) {
LOG.warn("Illegal access in field", e);
}
}
if (Property.class.isAssignableFrom(c)) {
try {
Property p = (Property) f.get(null);
if (p != null) {
known.add(p.getName());
}
} catch (IllegalArgumentException e) {
LOG.warn("Illegal argument in field", e);
} catch (IllegalAccessException e) {
LOG.warn("Illegal access in field", e);
}
}
}
}
}
public static boolean isMetadataField(String name) {
return known.contains(name);
}
public static boolean isMetadataField(Property property) {
return known.contains(property.getName());
}
}