org.rifidi.emulator.reader.thingmagic.commandobjects.DeclareCommand.java Source code

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Here is the source code for org.rifidi.emulator.reader.thingmagic.commandobjects.DeclareCommand.java

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/*
 *  DeclareCommand.java
 *
 *  Created:   August 7, 2008
 *  Project:   RiFidi Emulator - A Software Simulation Tool for RFID Devices
 *              http://www.rifidi.org
 *              http://rifidi.sourceforge.net
 *  Copyright:   Pramari LLC and the Rifidi Project
 *  License:   Lesser GNU Public License (LGPL)
 *              http://www.opensource.org/licenses/lgpl-license.html
 */
package org.rifidi.emulator.reader.thingmagic.commandobjects;

import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.rifidi.emulator.reader.thingmagic.commandobjects.exceptions.CommandCreationException;
import org.rifidi.emulator.reader.thingmagic.module.ThingMagicReaderSharedResources;

/**
 * @author Jerry Maine - jerry@pramari.com
 * 
 */
public class DeclareCommand extends Command {
    private static Log logger = LogFactory.getLog(DeclareCommand.class);

    private String cursorName;

    private Command cursorCommand;

    private ThingMagicReaderSharedResources tmsr;

    String command;

    public DeclareCommand(String command, ThingMagicReaderSharedResources tmsr) throws CommandCreationException {

        this.tmsr = tmsr;
        this.command = command;

        List<String> tokens = tokenizer(command);

        ListIterator<String> tokenIterator = tokens.listIterator();

        String token = tokenIterator.next();

        if (!token.equals("declare"))
            throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

        try {
            token = tokenIterator.next();

            if (!token.matches(WHITE_SPACE))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            token = tokenIterator.next();
            if (token.matches(A_WORD)) {
                cursorName = token;
                logger.debug("Cursor name is " + cursorName);
            } else {
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");
            }
            token = tokenIterator.next();

            if (!token.matches(WHITE_SPACE))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            token = tokenIterator.next();

            if (!token.equals("cursor"))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            token = tokenIterator.next();

            if (!token.matches(WHITE_SPACE))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            token = tokenIterator.next();

            if (!token.equals("for"))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            token = tokenIterator.next();

            if (!token.matches(WHITE_SPACE))
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

            StringBuffer cursorCommandBuf = new StringBuffer();
            token = tokenIterator.next();

            cursorCommandBuf.append(token);

            while (tokenIterator.hasNext()) {
                cursorCommandBuf.append(tokenIterator.next());
            }

            logger.debug("Command is \"" + cursorCommandBuf.toString() + "\"");

            if (token.equals("select")) {
                cursorCommand = new SelectCommand(cursorCommandBuf.toString(), tmsr);
            } else if (token.equals("update")) {
                cursorCommand = new UpdateCommand(cursorCommandBuf.toString(), tmsr);
            } else {
                throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");
            }

            /*
             * The SelectCommand and UpdateCommand both check for the semicolon
             * at the end, so we don't have to do that here.
             */
        } catch (NoSuchElementException e) {
            /*
             * if we get here... we run out of tokens prematurely... Our job now
             * is to walk backwards to find the last non space tokens and throw
             * an exception saying that there is an syntax error at that point.
             */

            /*
             * look for the last offending command block that is not a series of
             * whitespaces.
             */

            token = tokenIterator.previous();
            while (token.matches("\\s+")) {
                token = tokenIterator.previous();
            }
            logger.debug("Premature end of token list detected.");
            throw new CommandCreationException("Error 0100:     syntax error at '" + token + "'");

        }

        // if (!(tmsr.getCursorCommandRegistry().size() <= 16)) {
        // /* we can only hold no more than 16 cursors
        // *
        // */
        //         
        // //TODO Correct the messsage.
        // throw new CommandCreationExeption(
        // "Error 0100:     Can not old no more than 16 cursors.");
        // }

        if (tmsr.getCursorCommandRegistry().containsKey(cursorName)) {
            // TODO Correct the message.
            throw new CommandCreationException("Error 0100:   Cursor already exists");
        }

    }

    @Override
    public ArrayList<Object> execute() {

        tmsr.getCursorCommandRegistry().put(cursorName, cursorCommand);

        ArrayList<Object> retVal = new ArrayList<Object>();

        /*
         * there must be a blank line at the end.. even if we didn't send
         * something useful back.
         * 
         * When the messages are formated for return (in
         * ThingMagicRQLCommandFormatter) a new line is appended to each string
         * even if it is an empty string.
         */
        // place holder for newline.
        retVal.add("");

        return retVal;
    }

    @Override
    public String toCommandString() {
        // TODO Auto-generated method stub
        return command;
    }

}