enhancement-engines/tika/src/main/java/org/apache/stanbol/enhancer/engines/tika/handler/MultiHandler.java

/*
* 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.stanbol.enhancer.engines.tika.handler;

import java.util.Arrays;
import java.util.List;

import org.apache.tika.sax.ContentHandlerDecorator;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Similar to {@link ContentHandlerDecorator} - as it processed the exact same
 * methods - but supports forwarding such calls to several parsed {@link ContentHandler}s
 * 
 * @author Rupert Westenthaler
 *
 */
public class MultiHandler extends DefaultHandler {

    List<ContentHandler> handlers;

    public MultiHandler(ContentHandler...handlers) {
        if(handlers == null || handlers.length < 1){
            throw new IllegalArgumentException("The parsed ContentHandler array MUST NOT be NULL or empty!");
        }
        this.handlers = Arrays.asList(handlers);
        if(this.handlers.contains(null)){
            throw new IllegalArgumentException("Tha parsed ContentHandlers array MUST NOT contain an NULL entry!");
        }
    }

    @Override
    public void startPrefixMapping(String prefix, String uri) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.startPrefixMapping(prefix, uri);
        }
    }

    @Override
    public void endPrefixMapping(String prefix) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.endPrefixMapping(prefix);
        }
    }

    @Override
    public void processingInstruction(String target, String data) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.processingInstruction(target, data);
        }
    }

    @Override
    public void setDocumentLocator(Locator locator) {
        for(ContentHandler handler : handlers){
            handler.setDocumentLocator(locator);
        }
    }

    @Override
    public void startDocument() throws SAXException {
        for(ContentHandler handler : handlers){
            handler.startDocument();
        }
    }

    @Override
    public void endDocument() throws SAXException {
        for(ContentHandler handler : handlers){
            handler.endDocument();
        }
    }

    @Override
    public void startElement(String uri, String localName, String name, Attributes atts) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.startElement(uri, localName, name, atts);
        }
    }

    @Override
    public void endElement(String uri, String localName, String name) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.endElement(uri, localName, name);
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.characters(ch, start, length);
        }
    }

    @Override
    public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.ignorableWhitespace(ch, start, length);
        }
    }

    @Override
    public void skippedEntity(String name) throws SAXException {
        for(ContentHandler handler : handlers){
            handler.skippedEntity(name);
        }
    }
    
}