/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * 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 com.sun.org.apache.xerces.internal.util;

import java.io.InputStream;

import java.io.IOException;

import java.io.Reader;

import com.sun.org.apache.xerces.internal.xni.XNIException;

import com.sun.org.apache.xerces.internal.xni.XMLResourceIdentifier;

import com.sun.org.apache.xerces.internal.xni.parser.XMLEntityResolver;

import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;

import javax.xml.catalog.CatalogException;

import org.xml.sax.EntityResolver;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

/**

 * This class wraps a SAX entity resolver in an XNI entity resolver.

 *

 * @see EntityResolver

 *

 * @author Andy Clark, IBM

 *

 */

public class EntityResolverWrapper

    implements XMLEntityResolver {

    //

    // Data

    //

    /** The SAX entity resolver. */

    protected EntityResolver fEntityResolver;

    //

    // Constructors

    //

    /** Default constructor. */

    public EntityResolverWrapper() {}

    /** Wraps the specified SAX entity resolver. */

    public EntityResolverWrapper(EntityResolver entityResolver) {

        setEntityResolver(entityResolver);

    } // <init>(EntityResolver)

    //

    // Public methods

    //

    /** Sets the SAX entity resolver. */

    public void setEntityResolver(EntityResolver entityResolver) {

        fEntityResolver = entityResolver;

    } // setEntityResolver(EntityResolver)

    /** Returns the SAX entity resolver. */

    public EntityResolver getEntityResolver() {

        return fEntityResolver;

    } // getEntityResolver():EntityResolver

    //

    // XMLEntityResolver methods

    //

    /**

     * Resolves an external parsed entity. If the entity cannot be

     * resolved, this method should return null.

     *

     * @param resourceIdentifier        contains the physical co-ordinates of the resource to be resolved

     *

     * @throws XNIException Thrown on general error.

     * @throws IOException  Thrown if resolved entity stream cannot be

     *                      opened or some other i/o error occurs.

     */

    public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)

        throws XNIException, IOException {

        // When both pubId and sysId are null, the user's entity resolver

        // can do nothing about it. We'd better not bother calling it.

        // This happens when the resourceIdentifier is a GrammarDescription,

        // which describes a schema grammar of some namespace, but without

        // any schema location hint. -Sg

        String pubId = resourceIdentifier.getPublicId();

        String sysId = resourceIdentifier.getExpandedSystemId();

        if (pubId == null && sysId == null)

            return null;

        // resolve entity using SAX entity resolver

        if (fEntityResolver != null && resourceIdentifier != null) {

            try {

                InputSource inputSource = fEntityResolver.resolveEntity(pubId, sysId);

                if (inputSource != null) {

                    String publicId = inputSource.getPublicId();

                    String systemId = inputSource.getSystemId();

                    String baseSystemId = resourceIdentifier.getBaseSystemId();

                    InputStream byteStream = inputSource.getByteStream();

                    Reader charStream = inputSource.getCharacterStream();

                    String encoding = inputSource.getEncoding();

                    XMLInputSource xmlInputSource =

                        new XMLInputSource(publicId, systemId, baseSystemId, true);

                    xmlInputSource.setByteStream(byteStream);

                    xmlInputSource.setCharacterStream(charStream);

                    xmlInputSource.setEncoding(encoding);

                    return xmlInputSource;

                }

            }

            // error resolving entity

            catch (SAXException e) {

                Exception ex = e.getException();

                if (ex == null) {

                    ex = e;

                }

                throw new XNIException(ex);

            }

            catch (CatalogException e) {

                throw new XNIException(e);

            }

        }

        // unable to resolve entity

        return null;

    } // resolveEntity(String,String,String):XMLInputSource

}