org.apache.tika.sax.PhoneExtractingContentHandler 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.sax;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.sax.CleanPhoneText;
import org.apache.tika.sax.ContentHandlerDecorator;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import java.util.Arrays;
import java.util.List;
/**
* Class used to extract phone numbers while parsing.
*
* Every time a document is parsed in Tika, the content is split into SAX events.
* Those SAX events are handled by a ContentHandler. You can think of these events
* as marking a tag in an HTML file. Once you're finished parsing, you can call
* handler.toString(), for example, to get the text contents of the file. On the other
* hand, any of the metadata of the file will be added to the Metadata object passed
* in during the parse() call. So, the Parser class sends metadata to the Metadata
* object and content to the ContentHandler.
*
* This class is an example of how to combine a ContentHandler and a Metadata.
* As content is passed to the handler, we first check to see if it matches a
* textual pattern for a phone number. If the extracted content is a phone number,
* we add it to the metadata under the key "phonenumbers". So, if you used this
* ContentHandler when you parsed a document, then called
* metadata.getValues("phonenumbers"), you would get an array of Strings of phone
* numbers found in the document.
*
* Please see the PhoneExtractingContentHandlerTest for an example of how to use
* this class.
*
*/
public class PhoneExtractingContentHandler extends ContentHandlerDecorator {
private Metadata metadata;
private static final String PHONE_NUMBERS = "phonenumbers";
private StringBuilder stringBuilder;
/**
* Creates a decorator for the given SAX event handler and Metadata object.
*
* @param handler SAX event handler to be decorated
*/
public PhoneExtractingContentHandler(ContentHandler handler, Metadata metadata) {
super(handler);
this.metadata = metadata;
this.stringBuilder = new StringBuilder();
}
/**
* Creates a decorator that by default forwards incoming SAX events to
* a dummy content handler that simply ignores all the events. Subclasses
* should use the {@link #setContentHandler(ContentHandler)} method to
* switch to a more usable underlying content handler.
* Also creates a dummy Metadata object to store phone numbers in.
*/
protected PhoneExtractingContentHandler() {
this(new DefaultHandler(), new Metadata());
}
/**
* The characters method is called whenever a Parser wants to pass raw...
* characters to the ContentHandler. But, sometimes, phone numbers are split
* accross different calls to characters, depending on the specific Parser
* used. So, we simply add all characters to a StringBuilder and analyze it
* once the document is finished.
*/
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
try {
String text = new String(Arrays.copyOfRange(ch, start, start + length));
stringBuilder.append(text);
super.characters(ch, start, length);
} catch (SAXException e) {
handleException(e);
}
}
/**
* This method is called whenever the Parser is done parsing the file. So,
* we check the output for any phone numbers.
*/
@Override
public void endDocument() throws SAXException {
super.endDocument();
List numbers = CleanPhoneText.extractPhoneNumbers(stringBuilder.toString());
for (String number : numbers) {
metadata.add(PHONE_NUMBERS, number);
}
}
}