MyValidator.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://oss.oracle.com/licenses/CDDL+GPL-1.1
 * or LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package taglib;

import java.io.InputStream;
import java.io.IOException;

import javax.servlet.jsp.tagext.PageData;
import javax.servlet.jsp.tagext.TagLibraryValidator;
import javax.servlet.jsp.tagext.ValidationMessage;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class MyValidator extends TagLibraryValidator {

    public ValidationMessage[] validate(String prefix, String uri,
                                        PageData page) {

	/*
        StringBuffer sb = new StringBuffer();

        sb.append("---------- Prefix=" + prefix + " URI=" + uri +
                  "----------\n");

        InputStream is = page.getInputStream();
        while (true) {
            try {
                int ch = is.read();
                if (ch < 0) {
                    break;
                }
                sb.append((char) ch);
            } catch (IOException e) {
                break;
            }
        }
        sb.append("-----------------------------------------------");
        System.out.println(sb.toString());
	*/

        try {
	    DefaultHandler h = new DefaultHandler();

	    // parse the page
	    SAXParserFactory f = SAXParserFactory.newInstance();
	    f.setValidating(false);
	    f.setNamespaceAware(true);
	    SAXParser p = f.newSAXParser();
	    p.parse(page.getInputStream(), h);

	} catch (SAXException ex) {
	    return vmFromString(ex.toString());
	} catch (ParserConfigurationException ex) {
	    return vmFromString(ex.toString());
	} catch (IOException ex) {
	    return vmFromString(ex.toString());
	}

        return null;
    }

    // constructs a ValidationMessage[] from a single String and no ID
    private static ValidationMessage[] vmFromString(String message) {
	return new ValidationMessage[] {
	    new ValidationMessage(null, message)
	};
    }

}