com.lastcalc.servlets.StatelessServlet.java Source code

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Here is the source code for com.lastcalc.servlets.StatelessServlet.java

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/*******************************************************************************
 * LastCalc - The last calculator you'll ever need
 * Copyright (C) 2011, 2012 Uprizer Labs LLC
 * 
 * This program is free software: you can redistribute it and/or modify it 
 * under the terms of the GNU Affero General Public License as published 
 * by the Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version.
 * 
 * This program 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 Affero General Public License for more 
 * details.
 ******************************************************************************/
package com.lastcalc.servlets;

import java.io.IOException;
import java.util.*;
import java.util.Map.Entry;

import javax.servlet.ServletException;
import javax.servlet.http.*;

import com.google.common.collect.Maps;

import com.lastcalc.*;
import com.lastcalc.db.Line;
import com.lastcalc.parsers.UserDefinedParserParser.UserDefinedParser;
import com.lastcalc.parsers.currency.Currencies;

@SuppressWarnings("serial")
public class StatelessServlet extends HttpServlet {

    @Override
    public void init() throws ServletException {

    }

    @Override
    public void doPost(final HttpServletRequest req, final HttpServletResponse resp) throws IOException {
        final WorksheetRequest request = Misc.gson.fromJson(req.getReader(), WorksheetRequest.class);
        final WorksheetResponse response = new WorksheetResponse();
        if (request.getRecognizedWords) {
            response.recognizedWords = SequentialParser.recognizedWords;
        }
        final ArrayList<Line> qaPairs = new ArrayList<Line>();
        if (request.questions != null) {
            int earliestModified = Integer.MAX_VALUE;
            final TreeMap<Integer, String> orderedQuestions = Maps.newTreeMap();
            orderedQuestions.putAll(request.questions);
            for (final Entry<Integer, String> e : orderedQuestions.entrySet()) {
                final int pos = e.getKey() - 1;
                if (pos < qaPairs.size()) {
                    final Line qaPair = qaPairs.get(pos);
                    qaPair.question = e.getValue();
                    earliestModified = Math.min(earliestModified, pos);
                } else {
                    qaPairs.add(new Line(e.getValue(), null));
                }
            }
            for (int x = earliestModified; x < qaPairs.size(); x++) {
                final Line qaPair = qaPairs.get(x);
                qaPair.answer = null;
            }
            // Remove any qaPairs that have been removed from the browser DOM
            if (!orderedQuestions.isEmpty()) {
                while (qaPairs.size() > orderedQuestions.lastKey()) {
                    qaPairs.remove(qaPairs.size() - 1);
                }
            }
        }

        // Recompute worksheet
        final SequentialParser seqParser = SequentialParser.create();
        for (final Line qap : qaPairs) {
            if (qap.question.trim().length() == 0) {
                qap.answer = TokenList.createD();
            } else {
                if (qap.answer == null) {
                    qap.answer = seqParser.parseNext(Tokenizer.tokenize(qap.question));
                } else {
                    seqParser.processNextAnswer(qap.answer);
                }
            }
        }

        response.answers = Maps.newHashMap();
        response.answerTypes = Maps.newHashMap();
        response.variables = seqParser.getUserDefinedKeywordMap();

        for (int x = 0; x < qaPairs.size(); x++) {
            final TokenList answer = qaPairs.get(x).answer;
            final TokenList strippedAnswer = seqParser.stripUDF(answer);
            response.answers.put(x + 1, strippedAnswer.toString());
            response.answerTypes.put(x + 1,
                    strippedAnswer.size() == 1 && strippedAnswer.get(0) instanceof UserDefinedParser
                            ? AnswerType.FUNCTION
                            : AnswerType.NORMAL);
        }

        resp.setContentType("application/json; charset=UTF-8");
        Misc.gson.toJson(response, resp.getWriter());

        if (Currencies.shouldUpdate()) {
            Currencies.updateExchangeRates();
        }
    }

    public static class WorksheetRequest {
        public boolean getRecognizedWords = false;

        public String worksheetId;

        public Map<Integer, String> questions;
    }

    public static class WorksheetResponse {
        Set<String> recognizedWords;

        Map<Integer, String> answers;

        Map<Integer, AnswerType> answerTypes;

        Map<String, Integer> variables;
    }

    public enum AnswerType {
        NORMAL, FUNCTION, ERROR
    }
}