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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: FuncTranslate.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.functions;
     22 
     23 import org.apache.xpath.XPathContext;
     24 import org.apache.xpath.objects.XObject;
     25 import org.apache.xpath.objects.XString;
     26 
     27 /**
     28  * Execute the Translate() function.
     29  * @xsl.usage advanced
     30  */
     31 public class FuncTranslate extends Function3Args
     32 {
     33     static final long serialVersionUID = -1672834340026116482L;
     34 
     35   /**
     36    * Execute the function.  The function must return
     37    * a valid object.
     38    * @param xctxt The current execution context.
     39    * @return A valid XObject.
     40    *
     41    * @throws javax.xml.transform.TransformerException
     42    */
     43   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
     44   {
     45 
     46     String theFirstString = m_arg0.execute(xctxt).str();
     47     String theSecondString = m_arg1.execute(xctxt).str();
     48     String theThirdString = m_arg2.execute(xctxt).str();
     49     int theFirstStringLength = theFirstString.length();
     50     int theThirdStringLength = theThirdString.length();
     51 
     52     // A vector to contain the new characters.  We'll use it to construct
     53     // the result string.
     54     StringBuffer sbuffer = new StringBuffer();
     55 
     56     for (int i = 0; i < theFirstStringLength; i++)
     57     {
     58       char theCurrentChar = theFirstString.charAt(i);
     59       int theIndex = theSecondString.indexOf(theCurrentChar);
     60 
     61       if (theIndex < 0)
     62       {
     63 
     64         // Didn't find the character in the second string, so it
     65         // is not translated.
     66         sbuffer.append(theCurrentChar);
     67       }
     68       else if (theIndex < theThirdStringLength)
     69       {
     70 
     71         // OK, there's a corresponding character in the
     72         // third string, so do the translation...
     73         sbuffer.append(theThirdString.charAt(theIndex));
     74       }
     75       else
     76       {
     77 
     78         // There's no corresponding character in the
     79         // third string, since it's shorter than the
     80         // second string.  In this case, the character
     81         // is removed from the output string, so don't
     82         // do anything.
     83       }
     84     }
     85 
     86     return new XString(sbuffer.toString());
     87   }
     88 }
     89