/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-04 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.source;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.exist.dom.QName;
import org.exist.xquery.XPathException;
import org.exist.xquery.parser.DeclScanner;
import org.exist.xquery.parser.XQueryLexer;
import antlr.RecognitionException;
import antlr.TokenStreamException;
/**
* @author wolf
*/
public abstract class AbstractSource implements Source {
private long cacheTime = 0;
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (obj != null && obj instanceof Source) {
return getKey().equals(((Source)obj).getKey());
}
return false;
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return getKey().hashCode();
}
/* (non-Javadoc)
* @see org.exist.source.Source#getCacheTimestamp()
*/
public long getCacheTimestamp() {
return cacheTime;
}
/* (non-Javadoc)
* @see org.exist.source.Source#setCacheTimestamp(long)
*/
public void setCacheTimestamp(long timestamp) {
cacheTime = timestamp;
}
@Override
public QName isModule() throws IOException {
return null;
}
/**
* Check if the XQuery file declares a content encoding in the
* XQuery declaration.
*
* @param is
* @return The guessed encoding.
*/
protected final static String guessXQueryEncoding(InputStream is) {
final XQueryLexer lexer = new XQueryLexer(null, new InputStreamReader(is));
final DeclScanner scanner = new DeclScanner(lexer);
try {
scanner.versionDecl();
} catch (final RecognitionException e) {
//Nothing to do
} catch (final TokenStreamException e) {
//Nothing to do
} catch (final XPathException e) {
//Nothing to do
}
return scanner.getEncoding();
}
/**
* Check if the source is an XQuery module. If yes, return a QName containing
* the module prefix as local name and the module namespace as namespace URI.
*
* @param is
* @return QName describing the module namespace or null if the source is not
* a module.
*/
protected final static QName getModuleDecl(InputStream is) {
final XQueryLexer lexer = new XQueryLexer(null, new InputStreamReader(is));
final DeclScanner scanner = new DeclScanner(lexer);
try {
scanner.versionDecl();
} catch (final RecognitionException e) {
//Nothing to do
} catch (final TokenStreamException e) {
//Nothing to do
} catch (final XPathException e) {
//Nothing to do
}
if (scanner.getNamespace() != null) {
return new QName(scanner.getPrefix(), scanner.getNamespace());
}
return null;
}
}