saxbeanwriter.java

JAVA 文章管理系统源码

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed 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.commons.betwixt.io;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

// FIX ME
// At the moment, namespaces are NOT supported!

/**
 * The SAXBeanwriter will send events to a ContentHandler
 * 
 * @author <a href="mailto:[e-mail]">Robert Burrell Donkin</a>
 * @author <a href="mailto:[e-mail]">Martin van den Bemt</a>
 */
public class SAXBeanWriter extends AbstractBeanWriter {

    /** Where the output goes */
    private ContentHandler contentHandler;    
    /** Log used for logging (Doh!) */
    private Log log = LogFactory.getLog( SAXBeanWriter.class );
    /** Should document events (ie. start and end) be called? */
    private boolean callDocumentEvents = true;
    
    /**
     * <p> Constructor sets writer used for output.</p>
     *
     * @param contentHandler feed events to this content handler
     */
    public SAXBeanWriter(ContentHandler contentHandler) {
        this.contentHandler = contentHandler;
    }

    /** 
     * Should document events (ie start and end) be called?
     *
     * @return true if this SAXWriter should call start 
     * and end of the content handler
     * @since 0.5
     */
    public boolean getCallDocumentEvents() {
        return callDocumentEvents;
    }
    
    /**
     * Sets whether the document events (ie start and end) should be called.
     *
     * @param callDocumentEvents should document events be called
     * @since 0.5
     */
    public void setCallDocumentEvents(boolean callDocumentEvents) {
        this.callDocumentEvents = callDocumentEvents;
    }

    /**
     * <p> Set the log implementation used. </p>
     *
     * @return <code>Log</code> implementation that this class logs to
     */ 
    public Log getLog() {
        return log;
    }

    /**
     * <p> Set the log implementation used. </p>
     *
     * @param log <code>Log</code> implementation to use
     */ 
    public void setLog(Log log) {
        this.log = log;
    }
    
        
    // Expression methods
    //-------------------------------------------------------------------------     
    
    // Replaced by new API

    // New API
    // -------------------------------------------------------------------------

        
    /**
     * Writes the start tag for an element.
     *
     * @param uri the element's namespace uri
     * @param localName the element's local name 
     * @param qName the element's qualified name
     * @param attributes the element's attributes
     * @throws SAXException if an SAX problem occurs during writing 
     * @since 0.5
     */
    protected void startElement(
                                WriteContext context,
                                String uri, 
                                String localName, 
                                String qName, 
                                Attributes attributes)
                                    throws
                                        SAXException {
        contentHandler.startElement(
                                uri, 
                                localName, 
                                qName, 
                                attributes);
    }
    
    /**
     * Writes the end tag for an element
     *
     * @param uri the element's namespace uri
     * @param localName the element's local name 
     * @param qName the element's qualified name
     * @throws SAXException if an SAX problem occurs during writing 
     * @since 0.5
     */
    protected void endElement(
                                WriteContext context,
                                String uri, 
                                String localName, 
                                String qName)
                                    throws
                                        SAXException {
        contentHandler.endElement(
                                uri, 
                                localName, 
                                qName);
    }

    /** 
     * Express body text 
     * @param text the element body text 
     * @throws SAXException if the <code>ContentHandler</code> has a problem
     * @since 0.5
     */
    protected void bodyText(WriteContext context, String text) throws SAXException  {
    	//TODO:
        // FIX ME
        // CHECK UNICODE->CHAR CONVERSION!
        // THIS WILL QUITE POSSIBLY BREAK FOR NON-ROMAN
        char[] body = text.toCharArray();
        contentHandler.characters(body, 0, body.length);
    }  
    
    /**
     * This will announce the start of the document
     * to the contenthandler.
     * 
     * @see org.apache.commons.betwixt.io.AbstractBeanWriter#end()
     */
    public void start() throws SAXException {
        if ( callDocumentEvents ) {
            contentHandler.startDocument();
        }
    }

    /**
     * This method will announce the end of the document to
     * the contenthandler.
     * 
     * @see org.apache.commons.betwixt.io.AbstractBeanWriter#start()
     */
    public void end() throws SAXException {
        if ( callDocumentEvents ) {
            contentHandler.endDocument();
        }
    }
}