--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/software/eXist/mpdl-modules/src/org/exist/xquery/modules/mpdldoc/CheckUri.java	Wed Nov 24 17:24:23 2010 +0100
@@ -0,0 +1,91 @@
+/*
+ *  eXist Open Source Native XML Database: Extension module
+ *  Copyright (C) 2008 Josef Willenborg
+ *  jwillenborg@mpiwg-berlin.mpg.de
+ *  http://www.mpiwg-berlin.mpg.de
+ *  
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  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 Lesser General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *  
+ *  $Id:  $
+ */
+package org.exist.xquery.modules.mpdldoc;
+
+import java.io.IOException;
+import org.apache.commons.httpclient.HttpClient;
+import org.apache.commons.httpclient.methods.GetMethod;
+import org.apache.commons.httpclient.params.HttpClientParams;
+import org.apache.commons.httpclient.params.HttpMethodParams;
+import org.exist.dom.QName;
+import org.exist.xquery.BasicFunction;
+import org.exist.xquery.Cardinality;
+import org.exist.xquery.FunctionSignature;
+import org.exist.xquery.XPathException;
+import org.exist.xquery.XQueryContext;
+import org.exist.xquery.value.BooleanValue;
+import org.exist.xquery.value.NumericValue;
+import org.exist.xquery.value.Sequence;
+import org.exist.xquery.value.SequenceType;
+import org.exist.xquery.value.Type;
+
+/**
+ * @author Josef Willenborg (jwillenborg@mpiwg-berlin.mpg.de)
+ */
+public class CheckUri extends BasicFunction {
+
+	public final static FunctionSignature signature =
+		new FunctionSignature(
+			new QName("check-uri", MPDLDocModule.NAMESPACE_URI, MPDLDocModule.PREFIX),
+			"A function which checks the uri-string if it is available within a timeout value (in ms).",
+			new SequenceType[] { 
+			  new SequenceType(Type.STRING, Cardinality.ZERO_OR_ONE),
+        new SequenceType(Type.INTEGER, Cardinality.ZERO_OR_ONE)
+			  },
+			new SequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE));
+
+	public CheckUri(XQueryContext context) {
+		super(context, signature);
+	}
+
+  public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
+    Sequence isOk = BooleanValue.TRUE;
+    HttpClient httpClient = new HttpClient();
+    GetMethod method = null;
+    try {
+      Sequence firstSeq = args[0];
+      Sequence secondSeq = args[1];
+      if (firstSeq.isEmpty())
+        return isOk;
+      String uriStr = firstSeq.getStringValue();
+      int milliseconds = 2000; // default value
+      if (! secondSeq.isEmpty()) {
+        NumericValue value = (NumericValue) secondSeq.convertTo(Type.NUMBER);
+        milliseconds = value.getInt();
+      }
+      httpClient.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, new Integer(milliseconds));
+      httpClient.getParams().setParameter(HttpClientParams.CONNECTION_MANAGER_TIMEOUT, new Long(milliseconds));
+      method = new GetMethod(uriStr);
+      method.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, new Integer(milliseconds));
+      method.setFollowRedirects(true); 
+      httpClient.executeMethod(method); 
+    } catch (IOException e) {
+      isOk = BooleanValue.FALSE;  // if timeout exception is thrown
+    } finally {
+      if (method != null) {
+        method.releaseConnection();
+      }
+    }
+    return isOk;
+  }
+}