Handler.java

/****************************************************************************

 The contents of this file are subject to the Mozilla Public License
 Version 1.1 (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.mozilla.org/MPL/

 Software distributed under the License is distributed on an "AS IS" basis,
 WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
 the specific language governing rights and limitations under the License.

 The Original Code is TEAM Engine.

 The Initial Developer of the Original Code is Northrop Grumman Corporation
 jointly with The National Technology Alliance.  Portions created by
 Northrop Grumman Corporation are Copyright (C) 2005-2006, Northrop
 Grumman Corporation. All Rights Reserved.

 Contributor(s):
 Andreas Schmitz
 lat/lon GmbH
 Aennchenstr. 19, 53177 Bonn
 Germany
 http://lat-lon.de/

 ****************************************************************************/
package com.occamlab.te.util.protocols.data;

import static java.net.URLDecoder.decode;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.ArrayList;

import org.apache.xerces.impl.dv.util.Base64;

/**
 * 
 * @author <a href="mailto:schmitz@lat-lon.de">Andreas Schmitz</a>
 * @author last edited by: $Author: stranger $
 * 
 * @version $Revision$, $Date: 2010-08-09 00:08:36 -0700 (Mon, 09 Aug
 *          2010) $
 */
public class Handler extends URLStreamHandler {

    @Override
    protected URLConnection openConnection(URL u) throws IOException {
        String[] ss = u.getPath().split(",", 2);
        final String data = ss[1];
        ss = cleanup(ss[0].split(";"));

        String mime = "text/plain";
        String charset = "US-ASCII";
        String encoding = null;

        if (ss.length == 3) {
            mime = ss[0];
            charset = ss[1].split("=")[1];
            encoding = ss[2];
        } else if (ss.length == 2) {
            if (ss[0].startsWith("charset")) {
                charset = ss[0].split("=")[1];
                encoding = ss[1];
            } else {
                mime = ss[0];
                if (ss[1].startsWith("charset")) {
                    charset = ss[1].split("=")[1];
                } else {
                    encoding = ss[1];
                }
            }
        } else if (ss.length == 1) {
            if (ss[0].startsWith("charset")) {
                charset = ss[0].split("=")[1];
            } else {
                encoding = ss[0];
            }
        } else if (ss.length > 0) {
            System.out.println("too many fields");
        }

        if (encoding != null && !encoding.equalsIgnoreCase("base64")) {
            throw new IOException("The '" + encoding
                    + "' encoding is not supported by the data URL. "
                    + "Only base64 and the default of url-encoded is allowed.");
        }

        final String contentType = mime.length() == 0 ? "text/plain" : mime;
        final String characterEncoding = charset;

        if (encoding == null) {
            return new URLConnection(u) {
                InputStream in;

                {
                    connect();
                }

                @Override
                public void connect() throws IOException {
                    in = new ByteArrayInputStream(decode(data,
                            characterEncoding).getBytes("UTF-8"));
                }

                @Override
                public InputStream getInputStream() {
                    return in;
                }

                @Override
                public String getContentEncoding() {
                    return "UTF-8";
                }

                @Override
                public String getContentType() {
                    return contentType;
                }
            };
        }

        return new URLConnection(u) {
            InputStream in;

            {
                connect();
            }

            @Override
            public void connect() throws IOException {
                in = new ByteArrayInputStream(Base64.decode(data));
            }

            @Override
            public InputStream getInputStream() {
                return in;
            }

            @Override
            public String getContentEncoding() {
                return characterEncoding;
            }

            @Override
            public String getContentType() {
                return contentType;
            }
        };
    }

    private static String[] cleanup(String[] ss) {
        ArrayList<String> list = new ArrayList<String>();
        for (String s : ss) {
            if (s.length() > 0) {
                list.add(s);
            }
        }
        return list.toArray(new String[list.size()]);
    }

}