/*

  * Copyright 1999-2001,2004 The Apache Software Foundation.

  * 

  * Licensed 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.

  */ 

 package org.apache.commons.workflow.io;

 import java.io.BufferedOutputStream;

 import java.io.File;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.OutputStreamWriter;

 import java.util.EmptyStackException;

 import org.apache.commons.workflow.Context;

 import org.apache.commons.workflow.StepException;

 import org.apache.commons.workflow.base.BaseStep;

 /**

  * <p>Pop the top value from the evaluation stack, and write its contents

  * as a string to the specified file in the filesystem (replacing any

  * previous contents in that file).</p>

  *

  * <p>Supported Attributes:</p>

  * <ul>

  * <li><strong>encoding</strong> - Character encoding in which to write

  *     the characters to the specified file, or omitted for the platform

  *     default encoding.</li>

  * <li><strong>file</strong> - Relative or absolute operating system pathname

  *     whose contents are to be written.</li>

  * </ul>

  *

  * <strong>DESIGN QUESTION - What about binary content?</strong>

  *

  * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $

  * @author Craig R. McClanahan

  */

 public class WriteStep extends BaseStep {

     // ----------------------------------------------------------= Constructors

     /**

      * Construct a default instance of this Step.

      */

     public WriteStep() {

         super();

     }

     /**

      * Construct an instance of this Step with the specified identifier.

      *

      * @param id Step identifier

      */

     public WriteStep(String id) {

         super();

         setId(id);

     }

     /**

      * Construct a fully configured instance of this Step.

      *

      * @param id Step identifier

      * @param encoding Character encoding to use

      * @param file Relative or absolute pathname

      */

     public WriteStep(String id, String encoding, String file) {

         super();

         setId(id);

         setEncoding(encoding);

         setFile(file);

     }

     // ------------------------------------------------------------- Properties

     /**

      * The character encoding used to write the contents of this file.

      */

     protected String encoding = null;

     public String getEncoding() {

         return (this.encoding);

     }

     public void setEncoding(String encoding) {

         this.encoding = encoding;

     }

     /**

      * The relative or absolute pathname of the operating system file.

      */

     protected String file = null;

     public String getFile() {

         return (this.file);

     }

     public void setFile(String file) {

         this.file = file;

     }

     // --------------------------------------------------------- Public Methods

     /**

      * Perform the executable actions related to this Step, in the context of

      * the specified Context.

      *

      * @param context The Context that is tracking our execution state

      *

      * @exception StepException if a processing error has occurred

      */

     public void execute(Context context) throws StepException {

         // Pop the top value from the evaluation stack

         Object value = null;

         try {

             value = context.pop();

         } catch (EmptyStackException e) {

             throw new StepException("Evaluation stack is empty", e, this);

         }

         String string = null;

         if (value instanceof String)

             string = (String) value;

         else

             string = value.toString();

         // Define variables we will need later

         FileOutputStream fos = null;

         BufferedOutputStream bos = null;

         OutputStreamWriter osw = null;

         StepException se = null;

         try {

             // Construct a suitable OutputStreamWriter

             fos = new FileOutputStream(file);

             bos = new BufferedOutputStream(fos, 2048);

             if (encoding == null)

                 osw = new OutputStreamWriter(bos);

             else

                 osw = new OutputStreamWriter(bos, encoding);

             // Copy all characters to this file

             osw.write(string, 0, string.length());

             // Close the output file

             osw.flush();

             osw.close();

             osw = null;

             bos = null;

             fos = null;

         } catch (IOException e) {

             se = new StepException("IOException processing '" + file + "'",

                                    e, this);

         } finally {

             if (osw != null) {

                 try {

                     osw.close();

                 } catch (Throwable t) {

                     ;

                 }

             } else if (bos != null) {

                 try {

                     bos.close();

                 } catch (Throwable t) {

                     ;

                 }

             } else if (fos != null) {

                 try {

                     fos.close();

                 } catch (Throwable t) {

                     ;

                 }

             }

             if (se != null)

                 (new File(file)).delete();

         }

     }

 }