SourceLobFile.java
/*
** Module : SourceLobFile.java
** Abstract : A source 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 CA 20200427 I18nOps.convmap2Java uses uppercase keys.
** 004 OM 20210328 Improved copy lob engine and validations.
** OM 20210406 Delayed the stream opening for a later time when the file is actually accessed.
** 005 HC 20230118 Eliminated some of the uses of String.toUpperCase and/or String.toLowerCase
** for performance.
** 006 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
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** of Golden Code Development Corporation. You are not authorized to use the
** name Golden Code, FWD, or the names of any author or contributor, for
** publicity purposes without written authorization.
**
** 2. No Misrepresentation of Affiliation.
**
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**
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** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
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**
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** versions of the covered work must be marked in a reasonable way to make it
** clear that the modified work is not originating from Golden Code Development
** Corporation or FWD. All modified versions must contain the notices of
** attribution required in this license.
*/
package com.goldencode.p2j.util;
import java.io.*;
/**
* An object which represents a client-side file which is the source of a converted COPY-LOB statement.
*/
public class SourceLobFile
extends LobCopyInput
{
/** File stream for input file, which is a remote resource */
private Stream stream = null;
/** Marks the attempt to open the stream was performed. If it was successful, {@code stream != null}. */
private boolean opened = false;
/** The name of the actual file. */
private final String myFile;
/**
* Constructor which accepts a filename.
*
* @param filename
* Name of file from which to copy.
*/
public SourceLobFile(BaseDataType filename)
{
if (!(filename instanceof character))
{
ErrorManager.recordOrThrowError(11345);
myFile = null;
return;
}
myFile = getFilename((character) filename);
}
/**
* Constructor which accepts a filename.
*
* @param filename
* Name of file from which to copy.
*/
public SourceLobFile(String filename)
{
myFile = filename;
}
/**
* Constructor which accepts a filename.
*
* @param filename
* Name of file from which to copy. Must not be unknown.
*/
public SourceLobFile(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;
}
/**
* Read a specific number of characters from the file, starting at this parameter's offset.
*
* @return String read from the file.
*/
@Override
public String readString(String codePage)
{
if (!openStream())
{
// failed to open the stream
return null;
}
String charset = codePage != null && I18nOps.isSupported(codePage)
? I18nOps.convmap2Java.get(codePage)
: null;
InputStreamWrapper isw = new InputStreamWrapper(stream);
try (InputStreamReader reader = charset != null
? new InputStreamReader(isw, charset)
: new InputStreamReader(isw))
{
int off = getOffset();
int len = getLength();
char[] buf = new char[len];
reader.read(buf, off, len);
return new String(buf);
}
catch (IOException exc)
{
ErrorManager.recordOrThrowError(43, this.myFile, "13");
// ** Cannot find or open file <file-name>, errno = <number>. (43)
}
return null;
}
/**
* Read a specific number of bytes from the file, starting at this parameter's offset.
*
* @return Byte array read from the file.
*/
@Override
public byte[] readBytes()
{
if (!openStream())
{
// failed to open the stream
return null;
}
int off = getOffset();
int len = getLength();
try (InputStreamWrapper is = new InputStreamWrapper(stream))
{
// make sure we fit, and adjust parameters
int size = getSize();
if (size < len + off)
{
len = size - off;
if (len <= 0)
{
return new byte[0];
}
}
// skip first [offset] bytes
if (off > 0)
{
byte[] skip = new byte[off];
is.read(skip, 0, off);
}
// now we can grab the bytes we are interested, no more, no less
byte[] buf = new byte[len];
is.read(buf, 0, len);
return buf;
}
catch (IOException exc)
{
ErrorManager.recordOrThrowError(43, this.myFile, "13");
// ** Cannot find or open file <file-name>, errno = <number>. (43)
}
return null;
}
/**
* Obtain the name of the file.
*
* @return the name of the file.
*/
public String getFileName()
{
return myFile;
}
/**
* Checks if the optional offset is valid.
*
* @param targetType
* The type of the target object. The error messages are different in some cases (ignored?).
*
* @return {@code true} if the optional offset is valid.
*/
@Override
public boolean validateOffset(int targetType)
{
if (offset != null && (offset.isUnknown() || offset.intValue() <= 0))
{
ErrorManager.recordOrThrowError(11343);
// Unknown or invalid file offset specified in COPY-LOB statement. (11343)
return false;
}
return true;
}
/**
* Get the size of the object to be copied.
*
* @return Size of object, in bytes or characters, as appropriate to the object type.
*/
@Override
protected int getSize()
{
if (!openStream())
{
// failed to open the stream
return 0;
}
try
{
// cast is ok; max 4GL LOB size fits in integer
return (int) stream.getLen();
}
catch (IOException exc)
{
return 0;
}
}
/**
* Opens the stream if not already open. Otherwise nothing is performed.
*
* @return {@code true} if the stream can be used (ie. {@code stream != null}).
*/
private boolean openStream()
{
if (opened)
{
return stream != null;
}
opened = true;
try
{
stream = StreamFactory.openFileStream(myFile, false, false);
}
catch (DeferredLegacyErrorException dlee)
{
ErrorManager.recordOrThrowError(43, myFile, "2");
// ** Cannot find or open file <file-name>, errno = <number>. (43)
}
return stream != null;
}
/**
* 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(11345);
// Unknown or invalid source file specified in COPY-LOB statement. (11345)
return null;
}
return filename.toStringMessage();
}
}