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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one
      3  * or more contributor license agreements. See the NOTICE file
      4  * distributed with this work for additional information
      5  * regarding copyright ownership. The ASF licenses this file
      6  * to you under the Apache License, Version 2.0 (the  "License");
      7  * you may not use this file except in compliance with the License.
      8  * You may obtain a copy of the License at
      9  *
     10  *     http://www.apache.org/licenses/LICENSE-2.0
     11  *
     12  * Unless required by applicable law or agreed to in writing, software
     13  * distributed under the License is distributed on an "AS IS" BASIS,
     14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15  * See the License for the specific language governing permissions and
     16  * limitations under the License.
     17  */
     18 /*
     19  * $Id: FuncSum.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.functions;
     22 
     23 import org.apache.xml.dtm.DTM;
     24 import org.apache.xml.dtm.DTMIterator;
     25 import org.apache.xml.utils.XMLString;
     26 import org.apache.xpath.XPathContext;
     27 import org.apache.xpath.objects.XNumber;
     28 import org.apache.xpath.objects.XObject;
     29 
     30 /**
     31  * Execute the Sum() function.
     32  * @xsl.usage advanced
     33  */
     34 public class FuncSum extends FunctionOneArg
     35 {
     36     static final long serialVersionUID = -2719049259574677519L;
     37 
     38   /**
     39    * Execute the function.  The function must return
     40    * a valid object.
     41    * @param xctxt The current execution context.
     42    * @return A valid XObject.
     43    *
     44    * @throws javax.xml.transform.TransformerException
     45    */
     46   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
     47   {
     48 
     49     DTMIterator nodes = m_arg0.asIterator(xctxt, xctxt.getCurrentNode());
     50     double sum = 0.0;
     51     int pos;
     52 
     53     while (DTM.NULL != (pos = nodes.nextNode()))
     54     {
     55       DTM dtm = nodes.getDTM(pos);
     56       XMLString s = dtm.getStringValue(pos);
     57 
     58       if (null != s)
     59         sum += s.toDouble();
     60     }
     61     nodes.detach();
     62 
     63     return new XNumber(sum);
     64   }
     65 }
     66