Mercurial > dive4elements > river
diff flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/AbstractChartService.java @ 4213:0674d89210f5
Added a new service to query a diagram with discharge tables.
This service takes a gauge (required) and a timerange (optional) as input parameters.
author | Ingo Weinzierl <ingo.weinzierl@intevation.de> |
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date | Tue, 23 Oct 2012 07:39:09 +0200 |
parents | |
children | 61f4d4164a30 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/AbstractChartService.java Tue Oct 23 07:39:09 2012 +0200 @@ -0,0 +1,162 @@ +package de.intevation.flys.artifacts.services; + +import java.awt.Dimension; +import java.awt.Transparency; +import java.awt.image.BufferedImage; +import java.io.ByteArrayOutputStream; +import java.io.IOException; + +import javax.imageio.ImageIO; + +import org.apache.log4j.Logger; +import org.jfree.chart.JFreeChart; +import org.w3c.dom.Document; +import org.w3c.dom.Element; +import org.w3c.dom.NodeList; + +import de.intevation.artifactdatabase.DefaultService; +import de.intevation.artifacts.CallMeta; +import de.intevation.artifacts.GlobalContext; +import de.intevation.artifacts.Service; + + +public abstract class AbstractChartService extends DefaultService { + + public static final int DEFAULT_WIDTH = 240; + public static final int DEFAULT_HEIGHT = 180; + + public static final String DEFAULT_FORMAT = "png"; + + private static final Logger log = Logger + .getLogger(AbstractChartService.class); + + // TODO: Load fancy image from resources. + public static final byte[] EMPTY = { (byte) 0x89, (byte) 0x50, (byte) 0x4e, + (byte) 0x47, (byte) 0x0d, (byte) 0x0a, (byte) 0x1a, (byte) 0x0a, + (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x0d, (byte) 0x49, + (byte) 0x48, (byte) 0x44, (byte) 0x52, (byte) 0x00, (byte) 0x00, + (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, + (byte) 0x01, (byte) 0x08, (byte) 0x00, (byte) 0x00, (byte) 0x00, + (byte) 0x00, (byte) 0x3a, (byte) 0x7e, (byte) 0x9b, (byte) 0x55, + (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x73, + (byte) 0x52, (byte) 0x47, (byte) 0x42, (byte) 0x00, (byte) 0xae, + (byte) 0xce, (byte) 0x1c, (byte) 0xe9, (byte) 0x00, (byte) 0x00, + (byte) 0x00, (byte) 0x09, (byte) 0x70, (byte) 0x48, (byte) 0x59, + (byte) 0x73, (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13, + (byte) 0x00, (byte) 0x00, (byte) 0x0b, (byte) 0x13, (byte) 0x01, + (byte) 0x00, (byte) 0x9a, (byte) 0x9c, (byte) 0x18, (byte) 0x00, + (byte) 0x00, (byte) 0x00, (byte) 0x07, (byte) 0x74, (byte) 0x49, + (byte) 0x4d, (byte) 0x45, (byte) 0x07, (byte) 0xdc, (byte) 0x04, + (byte) 0x04, (byte) 0x10, (byte) 0x30, (byte) 0x15, (byte) 0x7d, + (byte) 0x77, (byte) 0x36, (byte) 0x0b, (byte) 0x00, (byte) 0x00, + (byte) 0x00, (byte) 0x08, (byte) 0x74, (byte) 0x45, (byte) 0x58, + (byte) 0x74, (byte) 0x43, (byte) 0x6f, (byte) 0x6d, (byte) 0x6d, + (byte) 0x65, (byte) 0x6e, (byte) 0x74, (byte) 0x00, (byte) 0xf6, + (byte) 0xcc, (byte) 0x96, (byte) 0xbf, (byte) 0x00, (byte) 0x00, + (byte) 0x00, (byte) 0x0a, (byte) 0x49, (byte) 0x44, (byte) 0x41, + (byte) 0x54, (byte) 0x08, (byte) 0xd7, (byte) 0x63, (byte) 0xf8, + (byte) 0x0f, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, + (byte) 0x00, (byte) 0x1b, (byte) 0xb6, (byte) 0xee, (byte) 0x56, + (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x49, + (byte) 0x45, (byte) 0x4e, (byte) 0x44, (byte) 0xae, (byte) 0x42, + (byte) 0x60, (byte) 0x82 }; + + private static final Output empty() { + return new Output(EMPTY, "image/png"); + } + + protected abstract JFreeChart createChart(Document data, + GlobalContext globalContext, CallMeta callMeta); + + protected void init() { + }; + + protected void finish() { + }; + + @Override + public Service.Output process(Document data, GlobalContext globalContext, + CallMeta callMeta) { + log.debug("process"); + + init(); + try { + JFreeChart chart = createChart(data, globalContext, callMeta); + + if (chart == null) { + return empty(); + } + + Dimension extent = getExtent(data); + String format = getFormat(data); + + return encode(chart, extent, format); + } + finally { + finish(); + } + } + + protected static Output encode(JFreeChart chart, Dimension extent, + String format) { + BufferedImage image = chart.createBufferedImage(extent.width, + extent.height, Transparency.BITMASK, null); + + ByteArrayOutputStream out = new ByteArrayOutputStream(); + + try { + ImageIO.write(image, format, out); + } + catch (IOException ioe) { + log.warn("writing image failed", ioe); + return empty(); + } + + return new Output(out.toByteArray(), "image/" + format); + } + + protected static Dimension getExtent(Document input) { + + int width = DEFAULT_WIDTH; + int height = DEFAULT_HEIGHT; + + NodeList extents = input.getElementsByTagName("extent"); + + if (extents.getLength() > 0) { + Element element = (Element) extents.item(0); + String w = element.getAttribute("width"); + String h = element.getAttribute("height"); + + try { + width = Math.max(1, Integer.parseInt(w)); + } + catch (NumberFormatException nfe) { + log.warn("width '" + w + "' is not a valid."); + } + + try { + height = Math.max(1, Integer.parseInt(h)); + } + catch (NumberFormatException nfe) { + log.warn("height '" + h + "' is not a valid"); + } + } + + return new Dimension(width, height); + } + + protected static String getFormat(Document input) { + String format = DEFAULT_FORMAT; + + NodeList formats = input.getElementsByTagName("format"); + + if (formats.getLength() > 0) { + String type = ((Element) formats.item(0)).getAttribute("type"); + if (type.length() > 0) { + format = type; + } + } + + return format; + } +}