org.apache.tika.parser.xml.AttributeDependantMetadataHandler 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.xml;
import org.apache.tika.metadata.Metadata;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
/**
* This adds a Metadata entry for a given node.
* The textual content of the node is used as the
* value, and the Metadata name is taken from
* an attribute, with a prefix if required.
*/
public class AttributeDependantMetadataHandler extends DefaultHandler {
private final Metadata metadata;
private final String nameHoldingAttribute;
private final String namePrefix;
private String name;
private final StringBuilder buffer = new StringBuilder();
public AttributeDependantMetadataHandler(Metadata metadata, String nameHoldingAttribute, String namePrefix) {
this.metadata = metadata;
this.nameHoldingAttribute = nameHoldingAttribute;
this.namePrefix = namePrefix;
}
public void addMetadata(String value) {
if(name == null || name.length() == 0) {
// We didn't find the attribute which holds the name
return;
}
if (value.length() > 0) {
String previous = metadata.get(name);
if (previous != null && previous.length() > 0) {
value = previous + ", " + value;
}
metadata.set(name, value);
}
}
public void endElement(String uri, String localName, String name) {
addMetadata(buffer.toString());
buffer.setLength(0);
}
public void startElement(
String uri, String localName, String name, Attributes attributes) {
String rawName = attributes.getValue(nameHoldingAttribute);
if (rawName != null) {
if (namePrefix == null) {
this.name = rawName;
} else {
this.name = namePrefix + rawName;
}
}
// All other attributes are ignored
}
public void characters(char[] ch, int start, int length) {
buffer.append(ch, start, length);
}
}