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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: FuncConcat.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.functions;
     22 
     23 import org.apache.xalan.res.XSLMessages;
     24 import org.apache.xpath.XPathContext;
     25 import org.apache.xpath.objects.XObject;
     26 import org.apache.xpath.objects.XString;
     27 
     28 /**
     29  * Execute the Concat() function.
     30  * @xsl.usage advanced
     31  */
     32 public class FuncConcat extends FunctionMultiArgs
     33 {
     34     static final long serialVersionUID = 1737228885202314413L;
     35 
     36   /**
     37    * Execute the function.  The function must return
     38    * a valid object.
     39    * @param xctxt The current execution context.
     40    * @return A valid XObject.
     41    *
     42    * @throws javax.xml.transform.TransformerException
     43    */
     44   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
     45   {
     46 
     47     StringBuffer sb = new StringBuffer();
     48 
     49     // Compiler says we must have at least two arguments.
     50     sb.append(m_arg0.execute(xctxt).str());
     51     sb.append(m_arg1.execute(xctxt).str());
     52 
     53     if (null != m_arg2)
     54       sb.append(m_arg2.execute(xctxt).str());
     55 
     56     if (null != m_args)
     57     {
     58       for (int i = 0; i < m_args.length; i++)
     59       {
     60         sb.append(m_args[i].execute(xctxt).str());
     61       }
     62     }
     63 
     64     return new XString(sb.toString());
     65   }
     66 
     67   /**
     68    * Check that the number of arguments passed to this function is correct.
     69    *
     70    *
     71    * @param argNum The number of arguments that is being passed to the function.
     72    *
     73    * @throws WrongNumberArgsException
     74    */
     75   public void checkNumberArgs(int argNum) throws WrongNumberArgsException
     76   {
     77     if (argNum < 2)
     78       reportWrongNumberArgs();
     79   }
     80 
     81   /**
     82    * Constructs and throws a WrongNumberArgException with the appropriate
     83    * message for this function object.
     84    *
     85    * @throws WrongNumberArgsException
     86    */
     87   protected void reportWrongNumberArgs() throws WrongNumberArgsException {
     88       throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("gtone", null));
     89   }
     90 }
     91