view flys-aft/src/main/java/de/intevation/aft/Notification.java @ 5779:ebec12def170

Datacage: Add a pool of builders to make it multi threadable. XML DOM is not thread safe. Therefore the old implementation only allowed one thread to use the builder at a time. As the complexity of the configuration has increased over time this has become a bottleneck of the whole application because it took quiet some time to build a result. Furthermore the builder code path is visited very frequent. So many concurrent requests were piled up resulting in long waits for the users. To mitigate this problem a round robin pool of builders is used now. Each of the pooled builders has an independent copy of the XML template and can be run in parallel. The number of builders is determined by the system property 'flys.datacage.pool.size'. It defaults to 4.
author Sascha L. Teichmann <teichmann@intevation.de>
date Sun, 21 Apr 2013 12:48:09 +0200
parents f939e1e6cfa4
children
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package de.intevation.aft;

import de.intevation.utils.XML;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

import org.apache.log4j.Logger;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Notification
{
    private static Logger log = Logger.getLogger(Notification.class);

    protected Document message;

    public Notification() {
    }

    public Notification(Document message) {
        this.message = message;
    }

    public Notification(Node message) {
        this(wrap(message));
    }

    public static Document wrap(Node node) {
        Document document = XML.newDocument();

        // Send first element as message.
        // Fall back to root node.
        Node toImport = node;

        NodeList children = node.getChildNodes();
        for (int i = 0, N = children.getLength(); i < N; ++i) {
            Node child = children.item(i);
            if (child.getNodeType() == Node.ELEMENT_NODE) {
                toImport = child;
                break;
            }
        }

        toImport = document.importNode(toImport, true);
        document.appendChild(toImport);
        document.normalizeDocument();
        return document;
    }

    public Document sendPOST(URL url) {

        OutputStream out    = null;
        InputStream  in     = null;
        Document     result = null;

        try {
            URLConnection ucon = url.openConnection();

            if (!(ucon instanceof HttpURLConnection)) {
                log.warn("NOTIFY: '" + url + "' is not an HTTP(S) connection.");
                return null;
            }

            HttpURLConnection con = (HttpURLConnection)ucon;

            con.setRequestMethod("POST");
            con.setDoInput(true);
            con.setDoOutput(true);
            con.setUseCaches(false);
            con.setRequestProperty("Content-Type", "text/xml");

            out = con.getOutputStream();
            XML.toStream(message, out);
            out.flush();
            in = con.getInputStream();
            result = XML.parseDocument(in);
        }
        catch (IOException ioe) {
            log.error("NOTIFY: Sending message to '" + url + "' failed.", ioe);
        }
        finally {
            if (out != null) {
                try { out.close(); } catch (IOException ioe) {}
            }
            if (in != null) {
                try { in.close(); } catch (IOException ioe) {}
            }
        }

        return result;
    }
}
// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

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