xmlformatter.java

High performance DB query

/*
 * @(#)$Id: XMLFormatter.java,v 1.4 2004/07/02 23:59:21 huebsch Exp $
 *
 * Copyright (c) 2001-2004 Regents of the University of California.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached BERKELEY-LICENSE
 * file. If you do not find these files, copies can be found by writing to:
 * Computer Science Division, Database Group, Universite of California,
 * 617 Soda Hall #1776, Berkeley, CA 94720-1776. Attention: Berkeley License
 *
 * Copyright (c) 2003-2004 Intel Corporation. All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE file.
 * If you do not find these files, copies can be found by writing to:
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300,
 * Berkeley, CA, 94704.  Attention:  Intel License Inquiry.
 */


package pier.helpers.formatters;

import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.util.Iterator;
import pier.data.Tuple;
import pier.data.TupleCollection;
import pier.query.QueryPlan;
import pier.query.QueryTag;

/**
 * Class XMLFormatter
 *
 * Need to:
 * - Create overall document header (and footer...)
 * - create tuple format
 * - error message schema (<error> string </error>)
 * - generic message schema  (<message> string </message>)
 *
 */
public class XMLFormatter extends SimpleFormatter {

    // xml tag
    public final static String XML_STRING =
        "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";

    // xml namespace stuff
    public final static String XIP_NAMESPACE_STRING =
        "xmlns:xip=\"urn:publicid:IDN+cde.berkeley.edu:schemas:XIP:200404\"";
    public final static String XMLSCHEMA_NAMESPACE_STRING =
        "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"";
    public final static String XIP_NAMESPACE_PREFIX = "xip";

    // XIPResultResponse Tags
    public final static String RESULT_RESPONSE_TAG = "XIPResultResponse";
    public final static String NUM_TUPLES_TAG = "NumTuples";
    public final static String TUPLE_COLLECTION_TAG = "Tuples";
    public final static String TUPLE_TAG = "Tuple";
    public final static String FIELD_TAG = "Field";

    // XipQueryResponse Tags
    public final static String QUERY_RESPONSE_TAG = "XIPQueryResponse";
    public final static String QID_TAG = "QID";
    public final static String REFNUM_TAG = "Refnum";
    public final static String QUERY_TAG_TAG = "QueryTag";
    public final static String QUERY_TAG = "Query";
    public final static String QUERY_STRING_TAG = "QueryString";

    // XipSchemaResponse Tags
    public final static String SCHEMA_RESPONSE_TAG = "XIPQueryResponse";

    // XIPMessage Tags
    public final static String MESSAGE_TAG = "XIPMessage";

    // XIPError Tags
    public final static String ERROR_TAG = "XIPError";

    /**
     * Method convertStringToBuffer
     *
     * @param string
     * @return
     */
    protected ByteBuffer convertStringToBuffer(String string) {
        ByteBuffer buffer = ByteBuffer.wrap(string.getBytes());

        buffer.position(0);

        return buffer;
    }

    /**
     * Method convertStringToBuffer
     *
     * @param stringBuffer
     * @return
     */
    protected ByteBuffer convertStringToBuffer(StringBuffer stringBuffer) {
        return convertStringToBuffer(stringBuffer.toString());
    }

    /**
     * Method escapeString
     * Escape XML characters
     *
     * @param string
     * @return
     */
    protected String escapeString(String string) {

        // Convert: & -> &amp;
        string = string.replaceAll("&", "&amp;");

        // Convert: < -> &lt;
        string = string.replaceAll("<", "&lt;");

        // Convert: > -> &gt;
        string = string.replaceAll(">", "&gt;");

        // Convert: ' -> &apos;
        string = string.replaceAll("\'", "&apos;");

        // Convert: " -> &quot;
        string = string.replaceAll("\"", "&quot;");

        return string;
    }

    /**
     * Method convertTupleToElement
     *
     * @param tuple
     * @return
     */
    public String convertTupleToElement(Tuple tuple) {
        String string = new String();

        string = string + "<" + TUPLE_TAG + ">";

        for (int i = 0; i < tuple.numFields(); i++) {
            string = string + "<" + FIELD_TAG + ">"
                     + escapeString(tuple.getValue(i).toString()) + "</"
                     + FIELD_TAG + ">";
        }

        string = string + "</" + TUPLE_TAG + ">";

        return string;
    }

    /**
     * Method formatTuple
     *
     * @param tuple
     * @param refnum
     * @param queryTag
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatTuple(Tuple tuple, int refnum, QueryTag queryTag,
                                  InetSocketAddress source, long time) {
        String tupleString = "<" + TUPLE_COLLECTION_TAG + ">";

        tupleString = tupleString + convertTupleToElement(tuple);
        tupleString = tupleString + "</" + TUPLE_COLLECTION_TAG + ">";

        return convertStringToBuffer(tupleString);
    }

    /**
     * Method formatTuples
     *
     * @param tuples
     * @param refnum
     * @param queryTag
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatTuples(TupleCollection tuples, int refnum,
                                   QueryTag queryTag, InetSocketAddress source,
                                   long time) {
        StringBuffer buffer = new StringBuffer();
        Iterator tupleIterator = tuples.iterator();

        buffer.append("<" + TUPLE_COLLECTION_TAG + ">");

        while (tupleIterator.hasNext()) {
            Tuple theTuple = (Tuple) tupleIterator.next();

            convertTupleToElement(theTuple);
        }

        buffer.append("</" + TUPLE_COLLECTION_TAG + ">");

        return convertStringToBuffer(buffer);
    }

    /**
     * Method formatQuery
     *
     * @param theQuery
     * @param refnum
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatQuery(String theQuery, int refnum,
                                  InetSocketAddress source, long time) {
        StringBuffer buffer = new StringBuffer();

        buffer.append("<" + QID_TAG + ">");
        buffer.append("<" + REFNUM_TAG + ">");
        buffer.append(refnum);
        buffer.append("</" + REFNUM_TAG + ">");
        buffer.append("</" + QID_TAG + ">");
        buffer.append("<" + QUERY_TAG + ">");
        buffer.append("<" + QUERY_STRING_TAG + ">");
        buffer.append(escapeString(theQuery));
        buffer.append("</" + QUERY_STRING_TAG + ">");
        buffer.append("</" + QUERY_TAG + ">");

        return convertStringToBuffer(buffer);
    }

    /**
     * Method formatQuery
     *
     * @param thePlan
     * @param refnum
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatQuery(QueryPlan thePlan, int refnum,
                                  InetSocketAddress source, long time) {
        return formatQuery(
            thePlan.toString(), refnum, source,
            time);    // dont distinguish between plan and query, for now
    }

    /**
     * Method formatMessage
     *
     * @param message
     * @param refnum
     * @param queryTag
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatMessage(String message, int refnum,
                                    QueryTag queryTag,
                                    InetSocketAddress source, long time) {
        StringBuffer buffer = new StringBuffer();

        buffer.append("<" + MESSAGE_TAG + ">");
        buffer.append(escapeString(message));
        buffer.append("</" + MESSAGE_TAG + ">");

        return convertStringToBuffer(buffer);
    }

    /**
     * Method formatError
     *
     * @param errorMessage
     * @param refnum
     * @param queryTag
     * @param source
     * @param time
     * @return
     */
    public ByteBuffer formatError(String errorMessage, int refnum,
                                  QueryTag queryTag, InetSocketAddress source,
                                  long time) {
        StringBuffer buffer = new StringBuffer();

        buffer.append("<" + ERROR_TAG + ">");
        buffer.append(escapeString(errorMessage));
        buffer.append("</" + ERROR_TAG + ">");

        return convertStringToBuffer(buffer);
    }

    /**
     * Method messagePreamble
     *
     *
     * @param messageType
     * @param time
     * @return
     */
    public ByteBuffer messagePreamble(int messageType, long time) {
        String str = XML_STRING;

        switch (messageType) {
        case MESSAGE_TYPE_QUERY_ECHO:
            str += "<" + XIP_NAMESPACE_PREFIX + ":" + QUERY_RESPONSE_TAG + " "
                   + XIP_NAMESPACE_STRING + " " + XMLSCHEMA_NAMESPACE_STRING
                   + " " + "xsi:schemaLocation=\"" + XIP_NAMESPACE_STRING + " "
                   + QUERY_RESPONSE_TAG + ".xsd\"" + ">";
            break;
        case MESSAGE_TYPE_ERROR:
            str += "<" + XIP_NAMESPACE_PREFIX + ":" + ERROR_TAG + " "
                   + XIP_NAMESPACE_STRING + " " + XMLSCHEMA_NAMESPACE_STRING
                   + " " + "xsi:schemaLocation=\"" + XIP_NAMESPACE_STRING + " "
                   + ERROR_TAG + ".xsd\"" + ">";
            break;
        case MESSAGE_TYPE_MESSAGE:
            str += "<" + XIP_NAMESPACE_PREFIX + ":" + MESSAGE_TAG + " "
                   + XIP_NAMESPACE_STRING + " " + XMLSCHEMA_NAMESPACE_STRING
                   + " " + "xsi:schemaLocation=\"" + XIP_NAMESPACE_STRING + " "
                   + MESSAGE_TAG + ".xsd\"" + ">";
            break;
        case MESSAGE_TYPE_SCHEMA:
            str += "<" + XIP_NAMESPACE_PREFIX + ":" + SCHEMA_RESPONSE_TAG + " "
                   + XIP_NAMESPACE_STRING + " " + XMLSCHEMA_NAMESPACE_STRING
                   + " " + "xsi:schemaLocation=\"" + XIP_NAMESPACE_STRING + " "
                   + SCHEMA_RESPONSE_TAG + ".xsd\"" + ">";
            break;
        case MESSAGE_TYPE_RESULT:
            str += "<" + XIP_NAMESPACE_PREFIX + ":" + RESULT_RESPONSE_TAG + " "
                   + XIP_NAMESPACE_STRING + " " + XMLSCHEMA_NAMESPACE_STRING
                   + " " + "xsi:schemaLocation=\"" + XIP_NAMESPACE_STRING + " "
                   + RESULT_RESPONSE_TAG + ".xsd\"" + ">";
            break;
        default:
            str = "</>";
        }

        return convertStringToBuffer(str);
    }

    /**
     * Method messagePostamble
     *
     *
     * @param messageType
     * @param time
     * @return
     */
    public ByteBuffer messagePostamble(int messageType, long time) {
        String str = "";

        switch (messageType) {
        case MESSAGE_TYPE_QUERY_ECHO:
            str = "</" + XIP_NAMESPACE_PREFIX + ":" + QUERY_RESPONSE_TAG + ">";
            break;
        case MESSAGE_TYPE_ERROR:
            str = "</" + XIP_NAMESPACE_PREFIX + ":" + ERROR_TAG + ">";
            break;
        case MESSAGE_TYPE_MESSAGE:
            str = "</" + XIP_NAMESPACE_PREFIX + ":" + MESSAGE_TAG + ">";
            break;
        case MESSAGE_TYPE_SCHEMA:
            str = "</" + XIP_NAMESPACE_PREFIX + ":" + SCHEMA_RESPONSE_TAG + ">";
            break;
        case MESSAGE_TYPE_RESULT:
            str = "</" + XIP_NAMESPACE_PREFIX + ":" + RESULT_RESPONSE_TAG + ">";
            break;
        default:
            str = "</>";
        }

        return convertStringToBuffer(str);
    }
}