code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the  "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id$
   */
  package org.apache.xpath.functions;
  
  import org.apache.xalan.res.XSLMessages;
  import org.apache.xpath.XPathContext;
  import org.apache.xpath.objects.XObject;
  import org.apache.xpath.objects.XString;
  
  /**
   * Execute the Concat() function.
   * @xsl.usage advanced
   */
  public class FuncConcat extends FunctionMultiArgs
  {
      static final long serialVersionUID = 1737228885202314413L;
  
    /**
     * Execute the function.  The function must return
     * a valid object.
     * @param xctxt The current execution context.
     * @return A valid XObject.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
    {
  
      StringBuffer sb = new StringBuffer();
  
      // Compiler says we must have at least two arguments.
      sb.append(m_arg0.execute(xctxt).str());
      sb.append(m_arg1.execute(xctxt).str());
  
      if (null != m_arg2)
        sb.append(m_arg2.execute(xctxt).str());
  
      if (null != m_args)
      {
        for (int i = 0; i < m_args.length; i++)
        {
          sb.append(m_args[i].execute(xctxt).str());
        }
      }
  
      return new XString(sb.toString());
    }
  
    /**
     * Check that the number of arguments passed to this function is correct.
     *
     *
     * @param argNum The number of arguments that is being passed to the function.
     *
     * @throws WrongNumberArgsException
     */
    public void checkNumberArgs(int argNum) throws WrongNumberArgsException
    {
      if (argNum < 2)
        reportWrongNumberArgs();
    }
  
    /**
     * Constructs and throws a WrongNumberArgException with the appropriate
     * message for this function object.
     *
     * @throws WrongNumberArgsException
     */
    protected void reportWrongNumberArgs() throws WrongNumberArgsException {
        throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("gtone", null));
    }
  }
  