ingo@4213: package de.intevation.flys.artifacts.services;
ingo@4213: 
ingo@4213: import java.awt.Dimension;
ingo@4213: import java.awt.Transparency;
ingo@4213: import java.awt.image.BufferedImage;
ingo@4213: import java.io.ByteArrayOutputStream;
ingo@4213: import java.io.IOException;
ingo@4213: 
ingo@4213: import javax.imageio.ImageIO;
ingo@4213: 
ingo@4213: import org.apache.log4j.Logger;
ingo@4213: import org.jfree.chart.JFreeChart;
ingo@4213: import org.w3c.dom.Document;
ingo@4213: import org.w3c.dom.Element;
ingo@4213: import org.w3c.dom.NodeList;
ingo@4213: 
ingo@4213: import de.intevation.artifactdatabase.DefaultService;
ingo@4213: import de.intevation.artifacts.CallMeta;
ingo@4213: import de.intevation.artifacts.GlobalContext;
ingo@4213: import de.intevation.artifacts.Service;
ingo@4213: 
felix@5343: /** Serve chart. */
ingo@4213: public abstract class AbstractChartService extends DefaultService {
ingo@4213: 
ingo@4213:     public static final int DEFAULT_WIDTH = 240;
ingo@4213:     public static final int DEFAULT_HEIGHT = 180;
ingo@4213: 
ingo@4213:     public static final String DEFAULT_FORMAT = "png";
ingo@4213: 
ingo@4213:     private static final Logger log = Logger
ingo@4213:         .getLogger(AbstractChartService.class);
ingo@4213: 
ingo@4213:     // TODO: Load fancy image from resources.
ingo@4213:     public static final byte[] EMPTY = { (byte) 0x89, (byte) 0x50, (byte) 0x4e,
ingo@4213:         (byte) 0x47, (byte) 0x0d, (byte) 0x0a, (byte) 0x1a, (byte) 0x0a,
ingo@4213:         (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x0d, (byte) 0x49,
ingo@4213:         (byte) 0x48, (byte) 0x44, (byte) 0x52, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x01, (byte) 0x08, (byte) 0x00, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x3a, (byte) 0x7e, (byte) 0x9b, (byte) 0x55,
ingo@4213:         (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x73,
ingo@4213:         (byte) 0x52, (byte) 0x47, (byte) 0x42, (byte) 0x00, (byte) 0xae,
ingo@4213:         (byte) 0xce, (byte) 0x1c, (byte) 0xe9, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x09, (byte) 0x70, (byte) 0x48, (byte) 0x59,
ingo@4213:         (byte) 0x73, (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13,
ingo@4213:         (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13, (byte) 0x01,
ingo@4213:         (byte) 0x00, (byte) 0x9a, (byte) 0x9c, (byte) 0x18, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x00, (byte) 0x07, (byte) 0x74, (byte) 0x49,
ingo@4213:         (byte) 0x4d, (byte) 0x45, (byte) 0x07, (byte) 0xdc, (byte) 0x04,
ingo@4213:         (byte) 0x04, (byte) 0x10, (byte) 0x30, (byte) 0x15, (byte) 0x7d,
ingo@4213:         (byte) 0x77, (byte) 0x36, (byte) 0x0b, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x08, (byte) 0x74, (byte) 0x45, (byte) 0x58,
ingo@4213:         (byte) 0x74, (byte) 0x43, (byte) 0x6f, (byte) 0x6d, (byte) 0x6d,
ingo@4213:         (byte) 0x65, (byte) 0x6e, (byte) 0x74, (byte) 0x00, (byte) 0xf6,
ingo@4213:         (byte) 0xcc, (byte) 0x96, (byte) 0xbf, (byte) 0x00, (byte) 0x00,
ingo@4213:         (byte) 0x00, (byte) 0x0a, (byte) 0x49, (byte) 0x44, (byte) 0x41,
ingo@4213:         (byte) 0x54, (byte) 0x08, (byte) 0xd7, (byte) 0x63, (byte) 0xf8,
ingo@4213:         (byte) 0x0f, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01,
ingo@4213:         (byte) 0x00, (byte) 0x1b, (byte) 0xb6, (byte) 0xee, (byte) 0x56,
ingo@4213:         (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x49,
ingo@4213:         (byte) 0x45, (byte) 0x4e, (byte) 0x44, (byte) 0xae, (byte) 0x42,
ingo@4213:         (byte) 0x60, (byte) 0x82 };
ingo@4213: 
ingo@4213:     private static final Output empty() {
ingo@4213:         return new Output(EMPTY, "image/png");
ingo@4213:     }
ingo@4213: 
ingo@4213:     protected abstract JFreeChart createChart(Document data,
ingo@4213:         GlobalContext globalContext, CallMeta callMeta);
ingo@4213: 
ingo@4213:     protected void init() {
ingo@4213:     };
ingo@4213: 
ingo@4213:     protected void finish() {
ingo@4213:     };
ingo@4213: 
ingo@4213:     @Override
ingo@4213:     public Service.Output process(Document data, GlobalContext globalContext,
ingo@4213:         CallMeta callMeta) {
ingo@4213:         log.debug("process");
ingo@4213: 
ingo@4213:         init();
ingo@4213:         try {
ingo@4213:             JFreeChart chart = createChart(data, globalContext, callMeta);
ingo@4213: 
ingo@4213:             if (chart == null) {
ingo@4213:                 return empty();
ingo@4213:             }
ingo@4213: 
ingo@4213:             Dimension extent = getExtent(data);
ingo@4213:             String format = getFormat(data);
ingo@4213: 
ingo@4213:             return encode(chart, extent, format);
ingo@4213:         }
ingo@4213:         finally {
ingo@4213:             finish();
ingo@4213:         }
ingo@4213:     }
ingo@4213: 
ingo@4213:     protected static Output encode(JFreeChart chart, Dimension extent,
ingo@4213:         String format) {
ingo@4213:         BufferedImage image = chart.createBufferedImage(extent.width,
ingo@4213:             extent.height, Transparency.BITMASK, null);
ingo@4213: 
ingo@4213:         ByteArrayOutputStream out = new ByteArrayOutputStream();
ingo@4213: 
ingo@4213:         try {
ingo@4213:             ImageIO.write(image, format, out);
ingo@4213:         }
ingo@4213:         catch (IOException ioe) {
ingo@4213:             log.warn("writing image failed", ioe);
ingo@4213:             return empty();
ingo@4213:         }
ingo@4213: 
ingo@4213:         return new Output(out.toByteArray(), "image/" + format);
ingo@4213:     }
ingo@4213: 
ingo@4213:     protected static Dimension getExtent(Document input) {
ingo@4213: 
ingo@4213:         int width = DEFAULT_WIDTH;
ingo@4213:         int height = DEFAULT_HEIGHT;
ingo@4213: 
ingo@4213:         NodeList extents = input.getElementsByTagName("extent");
ingo@4213: 
ingo@4213:         if (extents.getLength() > 0) {
ingo@4213:             Element element = (Element) extents.item(0);
ingo@4213:             String w = element.getAttribute("width");
ingo@4213:             String h = element.getAttribute("height");
ingo@4213: 
ingo@4213:             try {
ingo@4213:                 width = Math.max(1, Integer.parseInt(w));
ingo@4213:             }
ingo@4213:             catch (NumberFormatException nfe) {
ingo@4213:                 log.warn("width '" + w + "' is not a valid.");
ingo@4213:             }
ingo@4213: 
ingo@4213:             try {
ingo@4213:                 height = Math.max(1, Integer.parseInt(h));
ingo@4213:             }
ingo@4213:             catch (NumberFormatException nfe) {
ingo@4213:                 log.warn("height '" + h + "' is not a valid");
ingo@4213:             }
ingo@4213:         }
ingo@4213: 
ingo@4213:         return new Dimension(width, height);
ingo@4213:     }
ingo@4213: 
ingo@4213:     protected static String getFormat(Document input) {
ingo@4213:         String format = DEFAULT_FORMAT;
ingo@4213: 
ingo@4213:         NodeList formats = input.getElementsByTagName("format");
ingo@4213: 
ingo@4213:         if (formats.getLength() > 0) {
ingo@4213:             String type = ((Element) formats.item(0)).getAttribute("type");
ingo@4213:             if (type.length() > 0) {
ingo@4213:                 format = type;
ingo@4213:             }
ingo@4213:         }
ingo@4213: 
ingo@4213:         return format;
ingo@4213:     }
ingo@4213: }