ExportField.java
/*
** Module : ExportField.java
** Abstract : handle export data fields for I/O helpers
**
** Copyright (c) 2006-2022, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ---------------------------Description----------------------------
** 001 GES 20060925 @29901 Created initial version to export data fields for I/O helpers.
** 002 SIY 20071001 @35319 Made class suitable for network transfers. Ref: #35314
** 003 SIY 20071003 @35350 Added default constructor. Header cleanup. Fixed NPE during
** serialization. Ref: #35347.
** 004 GES 20160530 Use lambdas instead of Resolvable instances.
** 005 IAS 20200908 Rework (de)serialization.
** EVL 20221222 Adding LOB fields export service methods to simplify processing.
*/
/*
** 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
** 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.
**
** You may not represent yourself as Golden Code Development Corporation or FWD.
**
** You may not represent yourself for publicity purposes as associated with
** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
** 3. No Misrepresentation of Source or Origin.
**
** You may not represent the covered work as solely your work. All modified
** 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 static com.goldencode.util.NativeTypeSerializer.*;
import java.io.*;
import java.lang.management.*;
import java.util.concurrent.atomic.*;
import java.util.function.*;
/**
* Handles export formatted output of data fields for I/O helpers.
*/
public class ExportField
extends FieldEntry
{
/** Unique number for next LOB related file export operation. */
private static AtomicLong nextFSId = new AtomicLong(0);
/** The PID associated with current JVM instance. */
private static final String jvmPId;
/** The data to output to the stream. */
private Supplier<BaseDataType> data = null;
/** Resolved variable value. */
private BaseDataType savedVar = null;
/** Getting the current PID. */
static
{
String jvmName = ManagementFactory.getRuntimeMXBean().getName();
int pNdx = jvmName.indexOf("@");
jvmPId = jvmName.substring(0, pNdx);
}
/**
* Default constructor which is necessary to restores instance when it is transferred via
* the network.
*/
public ExportField()
{
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type.
*
* @param val
* The value to be output.
*/
public ExportField(int val)
{
this(new integer(val));
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type.
*
* @param val
* The value to be output.
*/
public ExportField(double val)
{
this(new decimal(val));
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type.
*
* @param val
* The value to be output.
*/
public ExportField(boolean val)
{
this(new logical(val));
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type.
*
* @param val
* The value to be output.
*/
public ExportField(String val)
{
this(new character(val));
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type.
*
* @param val
* The value to be output.
*/
public ExportField(final BaseDataType val)
{
this.data = () -> val;
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type. This form is used for field references.
*
* @param val
* The value to be output.
*/
public ExportField(final Resolvable val)
{
this.data = () -> val.resolve();
}
/**
* Generate output formatted using the <code>toStringExport</code> method of the associated
* type. This form is used for complex expressions whose evaluation bmust be deferred.
*
* @param val
* The function which supplies the value to be output.
*/
public ExportField(Supplier<BaseDataType> val)
{
this.data = val;
}
/**
* Renders the contained field definition to the given stream.
*
* @param out
* The stream to which the field should be rendered.
* @throws ErrorConditionException
*/
public void output(Stream out)
throws ErrorConditionException
{
BaseDataType bdt = data.get();
// use different methods for different data types
if (bdt instanceof memptr)
{
out.writeBlock((BinaryData) bdt);
}
else if (bdt instanceof blob)
{
out.writeBlob((blob) bdt);
}
else if (bdt instanceof clob)
{
out.writeClob((clob) bdt);
}
else
{
out.writeField(bdt);
}
}
/**
* Notify instance that it is about to be transferred so all resolvable data should be
* resolved and prepared for sending via network.
*/
public void resolveData()
{
savedVar = data.get();
}
/**
* Replacement for the default object reading method. The latest state is read from the
* input source.
*
* @param in
* The input source from which fields will be restored.
*
* @throws IOException
* In case of I/O errors.
* @throws ClassNotFoundException
* If payload can't be instantiated.
*/
public void readExternal(ObjectInput in)
throws IOException,
ClassNotFoundException
{
final BaseDataType data = readBaseDataType(in);
this.data = () -> data;
}
/**
* Replacement for the default object writing method. The latest state is written to the
* output destination.
*
* @param out
* The output destination to which fields will be saved.
*
* @throws IOException
* In case of I/O errors.
*/
public void writeExternal(ObjectOutput out)
throws IOException
{
writeBaseDataType(out, savedVar);
}
/**
* Gets the next unique integer number per JVM running instance to be used in file name reconstruction.
*
* @return The next number for separate export operation into file system.
*/
public static long getNextFSId()
{
return nextFSId.incrementAndGet();
}
/**
* Gets the current process ID for data exporting process.
*
* @return The current process ID as string value.
*/
public static String getJavaPId()
{
return jvmPId;
}
}