Java example source code file (ParserDelegator.java)

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Java - Java tags/keywords

appcontext, awt, bufferedinputstream, classnotfoundexception, datainputstream, dtd, dtd_key, inputstream, ioexception, object, parserdelegator, serializable, string, throwable

The ParserDelegator.java Java example source code

/*
 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.swing.text.html.parser;

import sun.awt.AppContext;

import javax.swing.text.html.HTMLEditorKit;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.DataInputStream;
import java.io.ObjectInputStream;
import java.io.Reader;
import java.io.Serializable;

/**
 * Responsible for starting up a new DocumentParser
 * each time its parse method is invoked. Stores a
 * reference to the dtd.
 *
 * @author  Sunita Mani
 */

public class ParserDelegator extends HTMLEditorKit.Parser implements Serializable {

    private static final Object DTD_KEY = new Object();

    protected static void setDefaultDTD() {
        getDefaultDTD();
    }

    private static synchronized DTD getDefaultDTD() {
        AppContext appContext = AppContext.getAppContext();

        DTD dtd = (DTD) appContext.get(DTD_KEY);

        if (dtd == null) {
            DTD _dtd = null;
            // (PENDING) Hate having to hard code!
            String nm = "html32";
            try {
                _dtd = DTD.getDTD(nm);
            } catch (IOException e) {
                // (PENDING) UGLY!
                System.out.println("Throw an exception: could not get default dtd: " + nm);
            }
            dtd = createDTD(_dtd, nm);

            appContext.put(DTD_KEY, dtd);
        }

        return dtd;
    }

    protected static DTD createDTD(DTD dtd, String name) {

        InputStream in = null;
        boolean debug = true;
        try {
            String path = name + ".bdtd";
            in = getResourceAsStream(path);
            if (in != null) {
                dtd.read(new DataInputStream(new BufferedInputStream(in)));
                dtd.putDTDHash(name, dtd);
            }
        } catch (Exception e) {
            System.out.println(e);
        }
        return dtd;
    }


    public ParserDelegator() {
        setDefaultDTD();
    }

    public void parse(Reader r, HTMLEditorKit.ParserCallback cb, boolean ignoreCharSet) throws IOException {
        new DocumentParser(getDefaultDTD()).parse(r, cb, ignoreCharSet);
    }

    /**
     * Fetch a resource relative to the ParserDelegator classfile.
     * If this is called on 1.2 the loading will occur under the
     * protection of a doPrivileged call to allow the ParserDelegator
     * to function when used in an applet.
     *
     * @param name the name of the resource, relative to the
     *  ParserDelegator class.
     * @returns a stream representing the resource
     */
    static InputStream getResourceAsStream(String name) {
        try {
            return ResourceLoader.getResourceAsStream(name);
        } catch (Throwable e) {
            // If the class doesn't exist or we have some other
            // problem we just try to call getResourceAsStream directly.
            return ParserDelegator.class.getResourceAsStream(name);
        }
    }

    private void readObject(ObjectInputStream s)
        throws ClassNotFoundException, IOException {
        s.defaultReadObject();
        setDefaultDTD();
    }
}