XmlRemapperIO.java
/*
** Module : XmlRemapperIO.java
** Abstract : Read/write RamRemapper data to/from XML.
**
** Copyright (c) 2005-2025, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ----------------Description-----------------
** 001 SIY 20050407 @21038 Created initial version, extracted
** from XmlRemapper.
** 002 ECF 20050421 @20805 Import p2j.xml package to use XmlHelper.
** 003 SIY 20050516 @21207 Updated documentation.
** 004 NVS 20060720 @28109 Any problem with reading from the directory
** XML throws a comprehensive exception so that
** the problem can be tracked down to a specific
** tree node.
** 005 GES 20080318 @37640 Switched from writer to stream to avoid
** unwanted character conversion when the
** default character set is not 8-bit ASCII.
** 006 GES 20090515 @42209 Imports change.
** 007 SIY 20091007 @44124 Replaced Vector with ArrayList.
** 008 SP 20250416 Code formatting and javadoc fixes.
*/
/*
** 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.directory;
import java.io.*;
import java.util.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import com.goldencode.p2j.*;
import com.goldencode.util.*;
/**
* This class perform input/output of the directory tree stored in
* <code>RamRemapper</code> and derived classes from/to backing XML file.
*
* @author SIY
* @version 1.0
*/
class XmlRemapperIO
{
/** XML attribute name for the node object class name */
private static final String ATTR_NODE_CLASS = "class";
/** XML attribute name for the node name */
private static final String ATTR_NODE_NAME = "name";
/** XML attribute name for the node attribute name */
private static final String ATTR_NODEATTR_NAME = "name";
/** XML attribute name for the node attribute value */
private static final String ATTR_NODEATTR_VALUE = "value";
/** XML tag for the node element */
private static final String ELEM_TAG_NODE = "node";
/** XML tag for the node attribute element */
private static final String ELEM_TAG_NODEATTR = "node-attribute";
/** XML tag for the root element */
private static final String ELEM_TAG_ROOT = "remapper-storage";
/** XML document */
private Document dom;
/**
* An instance of the <code>RamRemapper</code> used to retrieve object
* classes.
*/
private RamRemapper remapper;
/** XML document processor */
private final XmlProcessor processor;
/**
* Construct an instance of the <code>XmlRemapperIO</code>.
*
* @param remapper
* An instance of the <code>RamRemapper</code> which will be
* later saved or restored.
* @param processor
* Optional XML processing class.
*/
XmlRemapperIO(RamRemapper remapper, XmlProcessor processor)
{
this.remapper = remapper;
this.processor = processor;
dom = null;
}
/**
* Load tree from the XML document.
*
* @param in
* <code>InputStream</code> from which XML document will be
* read.
*
* @throws Exception
* Various exceptions are forwarded from <code>XmlHelper</code>
* or thrown in case of errors.
*/
void load(InputStream in)
throws Exception
{
dom = XmlHelper.parse(in);
Element elem = dom.getDocumentElement();
Node rootNode = elem.getFirstChild();
// find the first child that has a tagName "node"
while (rootNode != null && !rootNode.getNodeName().equals(ELEM_TAG_NODE))
{
rootNode = rootNode.getNextSibling();
}
RamNode root = readNode(rootNode);
if (root == null)
{
throw new MissingDataException("No valid root element");
}
else
{
if (processor != null)
{
processor.postprocess(dom);
}
}
remapper.setRoot(root);
}
/**
* Store tree into stream in XML file.
*
* @param out
* OutputStream which will be used to store XML.
*
* @throws ParserConfigurationException
* Forwarded from XmlHelper.
* @throws IOException
* Forwarded from XmlHelper.
*/
void save(OutputStream out)
throws ParserConfigurationException,
IOException
{
dom = XmlHelper.newDocument();
//Add comments
Comment comment;
comment = dom.createComment("XmlRemapper storage");
dom.appendChild(comment);
comment = dom.createComment("Saved " + (new Date()));
dom.appendChild(comment);
Element elem = dom.createElement(ELEM_TAG_ROOT);
dom.appendChild(elem);
writeNode(remapper.getRoot(), elem);
if (processor != null)
{
processor.preprocess(dom, elem);
}
XmlHelper.write(dom, out);
}
/**
* Read one node from the XML document.
*
* @param node
* Node instance to read data from.
*
* @return Instance of <code>RamNode</code> or <code>null</code> if
* something went wrong.
*/
private RamNode readNode(Node node)
{
if (node == null)
{
return null;
}
Element elem = (Element)node;
String nodeClass = elem.getAttribute(ATTR_NODE_CLASS);
String nodeName = elem.getAttribute(ATTR_NODE_NAME);
if (nodeClass == null)
{
throw new RuntimeException("node class not specified for name '" + nodeName + "'");
}
if (nodeName == null)
{
throw new RuntimeException("node name not specified for class '" + nodeClass + "'");
}
NodeList l = node.getChildNodes();
int i;
//First pass, construct attribute list
List<String> names = new ArrayList<>();
List<String> values = new ArrayList<>();
for (i = 0; i < l.getLength(); i++)
{
if (l.item(i).getNodeName().equals(ELEM_TAG_NODEATTR))
{
elem = (Element)l.item(i);
String strName = elem.getAttribute(ATTR_NODEATTR_NAME);
String strValue = elem.getAttribute(ATTR_NODEATTR_VALUE);
if (strName == null)
{
throw new RuntimeException("attribute name not specified for " + "class '" +
nodeClass + "' node '" + nodeName + "'");
}
if (strValue == null)
{
throw new RuntimeException("attribute value not specified for " + "class '" + nodeClass +
"' node '" + nodeName + "' attribute '" + strName + "'");
}
names.add(strName);
values.add(strValue);
}
}
RamNode ramNode;
//Restore container in the root
ramNode = new RamNode(remapper.getObjClass(nodeClass), nodeName);
for (i = 0; i < names.size(); i++)
{
String attrName = names.get(i);
String attrValue = values.get(i);
boolean rc = ramNode.addStringAttributeValue(attrName, attrValue);
if (!rc)
{
throw new RuntimeException("wrong attribute '" + attrName + "' in" + " class '" +
nodeClass + "' node '" + nodeName + "'");
}
}
if (!ramNode.isValid())
{
throw new RuntimeException("validation failed for class '" +
nodeClass + "' node '" + nodeName + "'");
}
//Second pass, rebuild child nodes
for (i = 0; i < l.getLength(); i++)
{
if (l.item(i).getNodeName().equals(ELEM_TAG_NODE))
{
RamNode rn = null;
try
{
rn = readNode(l.item(i));
}
catch (RuntimeException rte)
{
throw new RuntimeException("class '" + nodeClass + "' name '" + nodeName + "'", rte);
}
if (!ramNode.addChild(rn))
{
throw new RuntimeException("class '" + nodeClass + "' name '" +
nodeName + "' failed to add " + "child");
}
}
}
return ramNode;
}
/**
* Create and write one node into document. Call itself recursively for all
* child nodes.
*
* @param ramNode
* Directory tree node information about which should be written.
* @param parent
* Parent Document node which will hold information about new
* node.
*/
private void writeNode(RamNode ramNode, Node parent)
{
Element elem = dom.createElement(ELEM_TAG_NODE);
//Node class and name
elem.setAttribute(ATTR_NODE_CLASS, ramNode.getNodeClass().getName());
elem.setAttribute(ATTR_NODE_NAME, ramNode.getName());
parent.appendChild(elem);
//Node attributes.
Attribute[] attr = ramNode.getAttributes();
if (attr != null)
{
for (int i = 0; i < attr.length; i++)
{
String[] values = attr[i].getValues();
if (values == null)
{
continue;
}
for (int j = 0; j < values.length; j++)
{
Element nodeAttr = dom.createElement(ELEM_TAG_NODEATTR);
nodeAttr.setAttribute(ATTR_NODEATTR_NAME, attr[i].getName());
nodeAttr.setAttribute(ATTR_NODEATTR_VALUE, values[j]);
elem.appendChild(nodeAttr);
}
}
}
RamNode[] list = ramNode.getChildList();
if (list != null)
{
for (int i = 0; i < list.length; i++)
{
writeNode(list[i], elem);
}
}
}
}