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Calimero, a free KNX network library
/*
Calimero 2 - A library for KNX network access
Copyright (c) 2006, 2018 B. Malinowsky
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under terms
of your choice, provided that you also meet, for each linked independent
module, the terms and conditions of the license of that module. An
independent module is a module which is not derived from or based on
this library. If you modify this library, you may extend this exception
to your version of the library, but you are not obligated to do so. If
you do not wish to do so, delete this exception statement from your
version.
*/
package tuwien.auto.calimero.xml;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import org.slf4j.LoggerFactory;
/**
* Resolves resources during parsing XML.
*
* @author B. Malinowsky
*/
public final class XmlResolver
{
// IANA to Java encoding names map, used to specify existing charset decoders,
// only IANA names which are different from the java encoding names are listed
private static final Map javaNames = new HashMap<>();
static {
// add a new mapping of names, if value from "encoding"
// pseudo-attribute in declaration is not known by default
javaNames.put("LATIN1", "ISO-8859-1");
javaNames.put("ISO-10646-UCS-2", "UTF-16");
javaNames.put("EBCDIC-CP-US", "CP037");
javaNames.put("EBCDIC-CP-CA", "CP037");
javaNames.put("EBCDIC-CP-NL", "CP037");
javaNames.put("EBCDIC-CP-WT", "CP037");
}
/**
* Creates a new entity resolver.
*/
public XmlResolver()
{}
public Object resolveEntity(final String publicID, final String systemID, final String baseURI,
final String namespace) throws KNXMLException
{
try {
try {
LoggerFactory.getLogger("calimero.xml").trace("resolve {}", baseURI);
final URL loc = new URL(baseURI);
return loc.openConnection().getInputStream();
}
catch (final MalformedURLException e) {
return new FileInputStream(baseURI);
}
}
catch (final IOException e) {
throw new KNXMLException("error opening " + baseURI + ", " + e.getMessage());
}
}
OutputStream resolveOutput(final String systemID) throws KNXMLException
{
try {
try {
final URL loc = new URL(systemID);
return loc.openConnection().getOutputStream();
}
catch (final MalformedURLException e) {
return new FileOutputStream(systemID);
}
}
catch (final IOException e) {
throw new KNXMLException("error opening " + systemID + ", " + e.getMessage());
}
}
Reader getInputReader(final InputStream is) throws KNXMLException
{
InputStream in = null;
try {
in = new BufferedInputStream(is);
in.mark(9000);
// deduce encoding from first 4 bytes of stream
final byte[] start = new byte[4];
final int count = in.read(start);
in.reset();
final String encoding = getEncodingName(in, start, count);
in.mark(9000);
final Reader r = new InputStreamReader(in, encoding);
// search xml declaration
final char[] decl = new char[5];
r.read(decl);
if (!new String(decl).equals(" 1) {
// UTF-16, big-endian
if (b0 == 0xFE && b1 == 0xFF)
return "UTF-16BE";
// UTF-16, little-endian
if (b0 == 0xFF && b1 == 0xFE)
return "UTF-16LE";
}
if (count >= 3)
// UTF-8 with a BOM
if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) {
try {
is.skip(3);
}
catch (final IOException ignore) {}
return "UTF-8";
}
if (count == 4) {
final byte[][] arrays = {
// UCS-4, big endian
{ (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x3C },
// UCS-4, little endian
{ (byte) 0x3C, (byte) 0x00, (byte) 0x00, (byte) 0x00 },
// UTF-16, big-endian
{ (byte) 0x00, (byte) 0x3C, (byte) 0x00, (byte) 0x3F },
// UTF-16, little-endian
{ (byte) 0x3C, (byte) 0x00, (byte) 0x3F, (byte) 0x00 },
// EBCDIC, returns CP037 like xerces
{ (byte) 0x4C, (byte) 0x6F, (byte) 0xA7, (byte) 0x94 } };
final String[] encodings = {
"ISO-10646-UCS-4", "ISO-10646-UCS-4", "UTF-16BE", "UTF-16LE", "CP037" };
for (int i = 0; i < encodings.length; ++i)
if (Arrays.equals(arrays[i], start))
return encodings[i];
}
// default encoding
return "UTF-8";
}
// returns array with length 3 and optional entries version, encoding, standalone
private static String[] readXMLDeclaration(final Reader r) throws KNXMLException
{
final StringBuilder buf = new StringBuilder(100);
try {
for (int c = r.read(); c != -1 && c != '?'; c = r.read())
buf.append((char) c);
}
catch (final IOException e) {
throw new KNXMLException("reading XML declaration, " + e.getMessage(), buf
.toString(), 0);
}
String s = buf.toString().trim();
String version = null;
String encoding = null;
String standalone = null;
for (int state = 0; state < 3; ++state)
if (state == 0 && s.startsWith("version")) {
version = getAttValue(s = s.substring(7));
s = s.substring(s.indexOf(version) + version.length() + 1).trim();
}
else if (state == 1 && s.startsWith("encoding")) {
encoding = getAttValue(s = s.substring(8));
s = s.substring(s.indexOf(encoding) + encoding.length() + 1).trim();
}
else if (state == 1 || state == 2) {
if (s.startsWith("standalone")) {
standalone = getAttValue(s = s.substring(10));
if (!standalone.equals("yes") && !standalone.equals("no"))
throw new KNXMLException("invalid standalone pseudo-attribute",
standalone, 0);
break;
}
}
else
throw new KNXMLException("unknown XML declaration pseudo-attribute", s, 0);
return new String[] { version, encoding, standalone };
}
private static String getAttValue(final String s) throws KNXMLException
{
final String att = s.trim();
if (att.charAt(0) == '=' && att.length() > 2) {
final String v = att.substring(1).trim();
if (v.length() > 1 && (v.charAt(0) == '\'' || v.charAt(0) == '\"')) {
final int end = v.indexOf(v.charAt(0), 1);
if (end != -1)
return v.substring(1, end);
}
}
throw new KNXMLException("no pseudo-attribute value found", att, 0);
}
}