appserver/web/web-core/src/main/java/org/apache/catalina/util/SchemaResolver.java

/*
 * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
 * Copyright 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.catalina.util;


import org.apache.tomcat.util.digester.Digester;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
// END PWC 6457880

/**
 * This class implements a local SAX's <code>EntityResolver</code>. All
 * DTDs and schemas used to validate the web.xml file will re-directed
 * to a local file stored in the servlet-api.jar and jsp-api.jar.
 *
 * @author Jean-Francois Arcand
 */
public class SchemaResolver implements EntityResolver {

    /**
     * The digester instance for which this class is the entity resolver.
     */
    protected Digester digester;


    /**
     * The URLs of dtds and schemas that have been registered, keyed by the
     * public identifier that corresponds.
     */
    protected HashMap<String, String> entityValidator = new HashMap<String, String>();


    /**
     * Extension to make the difference between DTD and Schema.
     */
    protected String schemaExtension = "xsd";

    // START PWC 6457880
    /**
     * Attribute value used to turn on/off network access of dtd/schema
     */
    private static boolean forceLocalSchema = false;
    // END PWC 6457880

    /**
     * Create a new <code>EntityResolver</code> that will redirect
     * all remote dtds and schema to a local destination.
     * @param digester schemaLocation the XML Schema used to validate xml instance.
     */
    public SchemaResolver(Digester digester) {
        this.digester = digester;
    }


    /**
     * Register the specified DTD/Schema URL for the specified public
     * identifier. This must be called before the first call to
     * <code>parse()</code>.
     *
     * When adding a schema file (*.xsd), only the name of the file
     * will get added. If two schemas with the same name are added,
     * only the last one will be stored.
     *
     * @param publicId Public identifier of the DTD to be resolved
     * @param entityURL The URL to use for reading this DTD
     */
     public void register(String publicId, String entityURL) {
         String key = publicId;
         if (publicId.indexOf(schemaExtension) != -1)
             key = publicId.substring(publicId.lastIndexOf('/')+1);
         entityValidator.put(key, entityURL);
     }


    /**
     * Resolve the requested external entity.
     *
     * @param publicId The public identifier of the entity being referenced
     * @param systemId The system identifier of the entity being referenced
     *
     * @exception SAXException if a parsing exception occurs
     *
     */
    public InputSource resolveEntity(String publicId, String systemId)
        throws SAXException {

        if (publicId != null) {
            digester.setPublicId(publicId);
        }

        // Has this system identifier been registered?
        String entityURL = null;
        if (publicId != null) {
            entityURL = entityValidator.get(publicId);
        }

        // Redirect the schema location to a local destination
        String key = null;
        if (entityURL == null && systemId != null) {
            key = systemId.substring(systemId.lastIndexOf('/')+1);
            entityURL = entityValidator.get(key);
        }

/* PWC 6457880
        if (entityURL == null) {
           return (null);
        }

*/
        // START PWC 6457880
        if (entityURL == null) {
            if (forceLocalSchema) {
                URI u;
                try {
                    u  = new URI(systemId);
                } catch (URISyntaxException e) {
                    throw new SAXException(e);
                }
                String scheme = u.getScheme();
                // if the scheme is local, let the digester look it up
                // otherwise, throw an exception
                if (scheme != null && (scheme.equals("file") ||
                    scheme.equals("jar"))) {
                    return (null);
                }
                else {
                    throw new SAXException("Unable to find local schema for "+key);
                }
            }
            else {
                return (null);
            }
        }
        // END PWC 6457880
        try {
            return (new InputSource(entityURL));
        } catch (Exception e) {
            throw new SAXException(e);
        }

    }

    // START PWC 6457880
    public static void setForceLocalSchema(boolean flag) {
        forceLocalSchema = flag;
    }
    // END PWC 6457880
}