TargetLobFile.java

/*
** Module   : TargetLobFile.java
** Abstract : A target file parameter to a LobCopy operation.
**
** Copyright (c) 2019-2025, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 ECF 20190510 Created initial version.
** 002 ECF 20190628 Implemented COPY-LOB runtime.
** 003 OM  20210328 Improved COPY-LOB engine and validations.
**     OM  20210404 Used a getter to expose the file name.
**     EVL 20220406 Catching more exceptions to inform the target file is missing or invalid.
**     TJD 20220607 Switch to OutputStreamWriter to allow chunked write
** 004 CA  20250422 The source and target in COPY-LOB can be POLY, added constructor overloads.
*/

/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
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**     name Golden Code, FWD, or the names of any author or contributor, for
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*/

package com.goldencode.p2j.util;

import java.io.*;

/**
 * Concrete implementation of a converted COPY-LOB target parameter, corresponding with the
 * {@code TO FILE target-filename [ APPEND ]} phrase.
 */
public class TargetLobFile
extends LobCopyOutput
{
   /** Name of target output file, which is a remote resource */
   private final String filename;
   
   /** Whether to append to current file; if {@code false}, overwrite any existing content */
   private boolean append = false;
   
   /**
    * Constructor which accepts a filename.
    * 
    * @param   filename
    *          Name of file from which to copy.
    */
   public TargetLobFile(BaseDataType filename)
   {
      if (!(filename instanceof character))
      {
         ErrorManager.recordOrThrowError(11346);
         this.filename = null;
         return;
      }

      this.filename = getFilename((character) filename);
   }

   /**
    * Constructor which accepts a filename.
    * 
    * @param   filename
    *          Name of file from which to copy.
    */
   public TargetLobFile(String filename)
   {
      this.filename = filename;
   }
   
   /**
    * Constructor which accepts a filename.
    * 
    * @param   filename
    *          Name of file from which to copy. Must not be unknown.
    */
   public TargetLobFile(character filename)
   {
      this(getFilename(filename));
   }
   
   /**
    * Obtain the type of the object wrapped by this parameter
    *
    * @return  Always {@code LobCopyParameter.TYPE_FILE}.
    */
   @Override
   public int getObjectType()
   {
      return TYPE_FILE;
   }
   
   /**
    * Configure the copy to append to the target file instead of overwriting it.
    * 
    * @return  This object instance, to allow method chaining.
    */
   public TargetLobFile append()
   {
      this.append = true;
      
      return this;
   }
   
   /**
    * Assign the given array of bytes as the data managed by this object.
    * 
    * @param   data
    *          Data to be assigned to this object.
    */
   @Override
   public void write(byte[] data)
   {
      if (data == null)
      {
         // if the source is unknown (so the [data] is null) the file will still be created but empty 
         data = new byte[0];
      }
      Stream stream = openStream();
      if (stream == null)
      {
         return;
      }
      // underlying stream will be closed by wrapper at the end of write
      try (OutputStreamWrapper os = new OutputStreamWrapper(stream))
      {
         os.write(data);
      }
      catch (IOException exc)
      {
         ErrorManager.recordOrThrowError(43, filename, "13");
         // ** Cannot find or open file <file-name>, errno = <number>. (43)
      }

   }
   
   /**
    * Assign the given character data as the data managed by this object.
    * 
    * @param   data
    *          Data to be assigned to this object.
    * @param   opcp
    *          Target OE codepage to be used in write operation.
    */
   @Override
   public void write(String data, String opcp)
   {
      String javaCS;
      if (opcp == null)
      {
         javaCS = I18nOps.getJavaCharset();
         
         if (javaCS == null)
         {
            javaCS = "UTF-8";
         }
      }
      else
      {
         javaCS = I18nOps.getJavaCharset(opcp);
         
         if (javaCS == null)
         {
            ErrorManager.recordOrThrowError(912, opcp.toUpperCase(), I18nOps.CONVERSION_MAP_FILE);
            // Code page attribute table for <code-page> was not found in <filename>. (912)
            return;
         }
      }
      
      Stream stream = openStream();
      if (stream == null)
      {
         return;
      }
      // underlying stream will be closed by wrapper at the end of write
      try (OutputStreamWrapper os = new OutputStreamWrapper(stream))
      {
         stream.write(data.getBytes(javaCS));
      }
      catch (IOException exc)
      {
         ErrorManager.recordOrThrowError(43, filename, "13");
         // ** Cannot find or open file <file-name>, errno = <number>. (43)
      }
   }
   
   /**
    * Obtain the file name of this wrapper.
    * 
    * @return  the file name of this wrapper.
    */
   public String getFilename()
   {
      return filename;
   }
   
   /**
    * Extract the filename from the given parameter. Raises an error if the specified object is
    * unknown value.
    *
    * @param   filename
    *          File name.
    *
    * @return  String value of file name.
    */
   private static String getFilename(character filename)
   {
      if (filename.isUnknown())
      {
         ErrorManager.recordOrThrowError(11346);
         // Unknown or invalid target file specified in COPY-LOB statement. (11346)
         return null;
      }
      
      return filename.toStringMessage();
   }
   
   /**
    * Open stream using StreamFactory for writing, optionally in append mode 
    * @return Stream object instance or null in case of failure
    */
   private Stream openStream()
   {
      /** File stream for output file, which is a remote resource */
      Stream stream = null;
      
      try
      {
         stream = StreamFactory.openFileStream(filename, true, append);
      }
      catch (DeferredLegacyErrorException dlee)
      {
         ErrorManager.recordOrThrowError(43, filename, "2");
         // ** Cannot find or open file <file-name>, errno = <number>. (43)
      }
      catch (ErrorConditionException ece)
      {
         ErrorManager.recordOrThrowError(43, filename, "3");
         // ** Cannot find or open file <file-name>, errno = <number>. (43)
      }
      return stream;
   }
}