org.kawanfw.sql.transport.TransportConverter.java Source code

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Here is the source code for org.kawanfw.sql.transport.TransportConverter.java

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/*
 * This file is part of AceQL. 
 * AceQL: Remote JDBC access over HTTP.                                     
 * Copyright (C) 2015,  KawanSoft SAS
 * (http://www.kawansoft.com). All rights reserved.                                
 *                                                                               
 * AceQL is free software; you can redistribute it and/or                 
 * modify it under the terms of the GNU Lesser General Public                    
 * License as published by the Free Software Foundation; either                  
 * version 2.1 of the License, or (at your option) any later version.            
 *                                                                               
 * AceQL 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             
 * Lesser General Public License for more details.                               
 *                                                                               
 * You should have received a copy of the GNU Lesser General Public              
 * License along with this library; if not, write to the Free Software           
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  
 * 02110-1301  USA
 *
 * Any modifications to this file must keep this entire header
 * intact.
 */
package org.kawanfw.sql.transport;

import java.util.logging.Level;

import org.apache.commons.lang3.StringUtils;
import org.kawanfw.commons.util.Base64;
import org.kawanfw.commons.util.ClientLogger;
import org.kawanfw.commons.util.FrameworkDebug;
import org.kawanfw.commons.util.Tag;

/**
 * @author Nicolas de Pomereu
 * 
 *         Convert a String to a transportable format, aka ascii 7 & HTML
 */
public class TransportConverter {
    /** Debug flag */
    private static boolean DEBUG = FrameworkDebug.isSet(TransportConverter.class);

    public static String CR_LF = System.getProperty("line.separator");

    public static final String KAWANFW_BYTES = "**!kawanfw_bytes!**";

    // To say there is a file to fetch from the server
    public static final String KAWANFW_BYTES_STREAM_FILE = "**!kawanfw_stream_file!**";
    public static final String KAWANFW_STREAM_FAILURE = "**!kawanfw_stream_failure!**";
    public static final String KAWANFW_STREAM_NULL = "**!kawanfw_stream_null!**";

    /**
     * Constructor
     */
    protected TransportConverter() {
        // Not allowed
    }

    /**
     * Convert a byte array to a "transportable" format: - Transform it to Hex
     * value as String - Prefix it with **!kawanfw_bytes!**"
     * 
     * @param x
     *            the byte array to transport
     * @return a byte array in transportable format
     */
    public static String toTransportFormat(byte[] x) {
        String encodedString = null;

        // Allow to set null values and "transport it":
        if (x == null) {
            encodedString = KAWANFW_BYTES + "null";
        } else {
            encodedString = KAWANFW_BYTES + Base64.byteArrayToBase64(x);
        }

        return encodedString;
    }

    /**
     * Transform a byte [] transported in hex prefixed by "**!kawanfw_bytes!**"
     * to it's orginal byte []
     * 
     * @param string
     *            the string that contains the bytes prefixed by
     *            "**!kawanfw_bytes!**"
     * @return the bytes
     */
    public static byte[] fromTransportFormatToBytes(String string) {
        String encodedString = StringUtils.substringAfter(string, KAWANFW_BYTES);

        if (encodedString.equals("null")) {
            return null;
        }

        try {
            byte[] bytes = Base64.base64ToByteArray(encodedString);
            return bytes;
        } catch (Exception e) {
            throw new IllegalArgumentException(
                    Tag.PRODUCT_PRODUCT_FAIL + "String is not in BASE64 format: " + encodedString, e);
        }

    }

    /**
     * Displays the given message if DEBUG is set.
     * 
     * @param s
     *            the debug message
     */

    @SuppressWarnings("unused")
    private static void debug(String s) {
        if (DEBUG) {
            ClientLogger.getLogger().log(Level.WARNING, s);
        }
    }

}