LookAheadXmlStreamReader.java
/*
** Module : LookAheadXmlStreamReader.java
** Abstract : XMLStreamReader with 'peek' operation.
**
** Copyright (c) 2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 IAS 20230426 Created initial version.
*/
/*
** 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.
**
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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.persist.serial;
import java.io.*;
import java.nio.*;
import java.util.*;
import javax.xml.namespace.*;
import javax.xml.stream.*;
import org.apache.commons.io.input.*;
/** XMLStreamReader with 'peek' operation. */
public class LookAheadXmlStreamReader
implements XMLStreamReader
{
/** Actual reader */
private final XMLStreamReader delegate;
/** Flag indicating that reader is used not for inferring DATASET/TEMP-TABLE structure */
private boolean notForInfer = true;
/** Last result of 'peek' */
private OptionalInt next = OptionalInt.empty();
/** Last saved local name */
private Optional<String> localName = Optional.empty();
/** Last saved list of attributes' names */
private List<QName> attrNames = new ArrayList<>();
/** Last saved list of attributes' local names */
private List<String> attrLocalNames = new ArrayList<>();
/** Last saved list of attributes' names */
private List<String> attrValues = new ArrayList<>();
/** Last saved namespace */
private String nsUri = null;
/** Last saved namespace prefix */
private String nsPrefix = null;
/**
* Factory method. Creates and returns a {@code LookAheadXmlStreamReader} which adds 'peek()' feature to
* the {@code delegate} reader.
*
* @param delegate
* The underlying reader instance.
*
* @return The wrapper instance.
*/
public static LookAheadXmlStreamReader wrap(XMLStreamReader delegate)
{
return new LookAheadXmlStreamReader(delegate);
}
/**
* Private c'tor used by the static factory method.
*
* @param delegate
* The underlying reader instance.
*/
private LookAheadXmlStreamReader(XMLStreamReader delegate)
{
this.delegate = delegate;
}
/**
* Set the flag indicating the reader is used for inferring DATASET/TEMP-TABLE structure.
*
* @param forInfer
* <code>true</true> if the reader is used for inferring DATASET/TEMP-TABLE structure.
*
* @return self object. Allows chained calls.
*/
public LookAheadXmlStreamReader inferMode(boolean forInfer)
{
this.notForInfer = !forInfer;
if (!forInfer)
{
localName = Optional.empty();
}
else
{
saveAttr();
}
return this;
}
/**
* Save attributes of the current element
*/
public void saveAttr()
{
if (notForInfer || delegate.getEventType() != XMLStreamReader.START_ELEMENT)
{
return;
}
localName = Optional.of(delegate.getLocalName());
nsPrefix = delegate.getPrefix();
nsUri = delegate.getNamespaceURI();
int attrs = delegate.getAttributeCount();
attrLocalNames.clear();
attrNames.clear();
attrValues.clear();
for (int i = 0; i < attrs; i++)
{
attrLocalNames.add(delegate.getAttributeLocalName(i));
attrNames.add(delegate.getAttributeName(i));
attrValues.add(delegate.getAttributeValue(i));
}
}
/**
* Peek the next parsing event.
*
* @return the next parsing event.
*
* @throws XMLStreamException
* if there is an error processing the underlying XML source.
*/
public int peek()
throws XMLStreamException
{
if (!next.isPresent())
{
next = OptionalInt.of(delegate.next());
}
return next.getAsInt();
}
/**
* @see javax.xml.stream.XMLStreamReader#close()
*/
public void close()
throws XMLStreamException
{
delegate.close();
}
/**
* Returns the numbers of saved attributes or calls delegate.
*
* @see javax.xml.stream.XMLStreamReader#getAttributeCount()
*
*/
public int getAttributeCount()
{
return localName.isPresent() ? attrNames.size() : delegate.getAttributeCount();
}
/**
* Returns the qname of the saved attribute at the provided index or calls delegate.
*
* @see javax.xml.stream.XMLStreamReader#getAttributeLocalName(int)
*/
public String getAttributeLocalName(int index)
{
return localName.isPresent() ? attrLocalNames.get(index) : delegate.getAttributeLocalName(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#getAttributeName(int)
*/
public QName getAttributeName(int index)
{
return localName.isPresent() ? attrNames.get(index) : delegate.getAttributeName(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#getAttributeNamespace(int)
*/
public String getAttributeNamespace(int index)
{
return delegate.getAttributeNamespace(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#getAttributePrefix(int)
*/
public String getAttributePrefix(int index)
{
return delegate.getAttributePrefix(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#getAttributeType(int)
*/
public String getAttributeType(int index)
{
return delegate.getAttributeType(index);
}
/**
* Returns the value of the saved attribute at the index or call delegate.
*
* @see javax.xml.stream.XMLStreamReader#getAttributeValue(int)
*/
public String getAttributeValue(int index)
{
return localName.isPresent() ? attrValues.get(index) : delegate.getAttributeValue(index);
}
/**
* Returns the normalized attribute value of the saved attribute with the namespace and localName
* or calls delegate.
*
* @see javax.xml.stream.XMLStreamReader#getAttributeValue(java.lang.String, java.lang.String)
*/
public String getAttributeValue(String namespaceURI, String localName)
{
return delegate.getAttributeValue(namespaceURI, localName);
}
/**
* @see javax.xml.stream.XMLStreamReader#getCharacterEncodingScheme()
*/
public String getCharacterEncodingScheme()
{
return delegate.getCharacterEncodingScheme();
}
/**
* @see javax.xml.stream.XMLStreamReader#getElementText()
*/
public String getElementText()
throws XMLStreamException
{
return delegate.getElementText();
}
/**
* @see javax.xml.stream.XMLStreamReader#getEncoding()
*/
public String getEncoding()
{
return delegate.getEncoding();
}
/**
* @see javax.xml.stream.XMLStreamReader#getEventType()
*/
public int getEventType()
{
return delegate.getEventType();
}
/**
* Returns the (local) name of the saved event or call delegate.
*
* @see javax.xml.stream.XMLStreamReader#getLocalName()
*/
public String getLocalName()
{
saveAttr();
return localName.isPresent() ? localName.get() : delegate.getLocalName();
}
/**
* @see javax.xml.stream.XMLStreamReader#getLocation()
*/
public Location getLocation()
{
return delegate.getLocation();
}
/**
* @see javax.xml.stream.XMLStreamReader#getName()
*/
public QName getName()
{
return delegate.getName();
}
/**
* @see javax.xml.stream.XMLStreamReader#getNamespaceContext()
*/
public NamespaceContext getNamespaceContext()
{
return delegate.getNamespaceContext();
}
/**
* @see javax.xml.stream.XMLStreamReader#getNamespaceCount()
*/
public int getNamespaceCount()
{
return delegate.getNamespaceCount();
}
/**
* @see javax.xml.stream.XMLStreamReader#getNamespacePrefix(int)
*/
public String getNamespacePrefix(int index)
{
return delegate.getNamespacePrefix(index);
}
/**
* Returns the URI of the prefix or the default namespace of the saved event or call delegate.
*
* @see javax.xml.stream.XMLStreamReader#getNamespaceURI()
*/
public String getNamespaceURI()
{
return localName.isPresent() ? nsUri : delegate.getNamespaceURI();
}
/**
* @see javax.xml.stream.XMLStreamReader#getNamespaceURI(int)
*/
public String getNamespaceURI(int index)
{
return delegate.getNamespaceURI(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#getNamespaceURI(java.lang.String)
*/
public String getNamespaceURI(String prefix)
{
return delegate.getNamespaceURI(prefix);
}
/**
* @see javax.xml.stream.XMLStreamReader#getPIData()
*/
public String getPIData()
{
return delegate.getPIData();
}
/**
* @see javax.xml.stream.XMLStreamReader#getPITarget()
*/
public String getPITarget()
{
return delegate.getPITarget();
}
/**
* Returns the prefix of the saved event or calls delegate.
*
* @see javax.xml.stream.XMLStreamReader#getPrefix()
*/
public String getPrefix()
{
return localName.isPresent() ? nsPrefix : delegate.getPrefix();
}
/**
* @see javax.xml.stream.XMLStreamReader#getProperty(java.lang.String)
*/
public Object getProperty(String name)
throws IllegalArgumentException
{
return delegate.getProperty(name);
}
/**
* @see javax.xml.stream.XMLStreamReader#getText()
*/
public String getText()
{
return delegate.getText();
}
/**
* @see javax.xml.stream.XMLStreamReader#getTextCharacters()
*/
public char[] getTextCharacters()
{
return delegate.getTextCharacters();
}
/**
* @see javax.xml.stream.XMLStreamReader#getTextCharacters(int, char[], int, int)
*/
public int getTextCharacters(int sourceStart, char[] target, int targetStart, int length)
throws XMLStreamException
{
return delegate.getTextCharacters(sourceStart, target, targetStart, length);
}
/**
* @see javax.xml.stream.XMLStreamReader#getTextLength()
*/
public int getTextLength()
{
return delegate.getTextLength();
}
/**
* @see javax.xml.stream.XMLStreamReader#getTextStart()
*/
public int getTextStart()
{
return delegate.getTextStart();
}
/**
* @see javax.xml.stream.XMLStreamReader#getVersion()
*/
public String getVersion()
{
return delegate.getVersion();
}
/**
* @see javax.xml.stream.XMLStreamReader#hasName()
*/
public boolean hasName()
{
return delegate.hasName();
}
/**
* @see javax.xml.stream.XMLStreamReader#hasNext()
*/
public boolean hasNext()
throws XMLStreamException
{
return delegate.hasNext();
}
/**
* @see javax.xml.stream.XMLStreamReader#hasText()
*/
public boolean hasText()
{
return delegate.hasText();
}
/**
* @see javax.xml.stream.XMLStreamReader#isAttributeSpecified(int)
*/
public boolean isAttributeSpecified(int index)
{
return delegate.isAttributeSpecified(index);
}
/**
* @see javax.xml.stream.XMLStreamReader#isCharacters()
*/
public boolean isCharacters()
{
return delegate.isCharacters();
}
/**
* @see javax.xml.stream.XMLStreamReader#isEndElement()
*/
public boolean isEndElement()
{
return delegate.isEndElement();
}
/**
* @see javax.xml.stream.XMLStreamReader#isStandalone()
*/
public boolean isStandalone()
{
return delegate.isStandalone();
}
/**
* @see javax.xml.stream.XMLStreamReader#isStartElement()
*/
public boolean isStartElement()
{
return delegate.isStartElement();
}
/**
* @see javax.xml.stream.XMLStreamReader#isWhiteSpace()
*/
public boolean isWhiteSpace()
{
return delegate.isWhiteSpace();
}
/**
* Get saved parsing event or calls delegate.
*
* @see javax.xml.stream.XMLStreamReader#next()
*/
public int next()
throws XMLStreamException
{
try
{
return next.isPresent() ? next.getAsInt() : delegate.next();
}
finally
{
next = OptionalInt.empty();
}
}
/**
* @see javax.xml.stream.XMLStreamReader#nextTag()
*/
public int nextTag()
throws XMLStreamException
{
return delegate.nextTag();
}
/**
* @see javax.xml.stream.XMLStreamReader#require(int, java.lang.String, java.lang.String)
*/
public void require(int type, String namespaceURI, String localName)
throws XMLStreamException
{
delegate.require(type, namespaceURI, localName);
}
/**
* @see javax.xml.stream.XMLStreamReader#standaloneSet()
*/
public boolean standaloneSet()
{
return delegate.standaloneSet();
}
}