org.tohu.examples.simple.pdf.PdfServlet.java Source code

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Here is the source code for org.tohu.examples.simple.pdf.PdfServlet.java

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/*
 * Copyright 2009 Solnet Solutions Limited (http://www.solnetsolutions.co.nz/)
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.tohu.examples.simple.pdf;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.drools.runtime.StatefulKnowledgeSession;
import org.tohu.util.QueryHelper;

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Paragraph;
import com.lowagie.text.pdf.PdfPTable;
import com.lowagie.text.pdf.PdfWriter;

import drools.rex.ExecutionServerHelper;

/**
 * Example of how you could extract the questions and their answers out. This calls the execution server and uses the output to
 * generate a simple PDF.
 *
 * @author Damon Horrell
 */
public class PdfServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        StatefulKnowledgeSession knowledgeSession = new ExecutionServerHelper(request.getSession())
                .getKnowledgeSession();
        Map<String, Object> answers = new QueryHelper(knowledgeSession).getAnswers();
        try {
            Document document = new Document();
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            PdfWriter.getInstance(document, baos);
            document.open();
            Paragraph title = new Paragraph("Simple Example");
            title.setAlignment("center");
            document.add(title);
            document.add(new Paragraph(" "));
            PdfPTable table = new PdfPTable(2);
            for (Map.Entry<String, Object> entry : answers.entrySet()) {
                table.addCell(entry.getKey());
                table.addCell(entry.getValue().toString());
            }
            document.add(table);
            document.add(new Paragraph(" "));
            document.add(new Paragraph(
                    new SimpleDateFormat("dd/MM/yyyy HH:mm").format(Calendar.getInstance().getTime())));
            document.close();
            response.setContentType("application/pdf");
            response.setContentLength(baos.size());
            ServletOutputStream out = response.getOutputStream();
            baos.writeTo(out);
            out.flush();
        } catch (DocumentException e) {
            throw new ServletException(e);
        }
    }
}