//AbstractParser.java
//------------------------
//part of YaCy
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2005
//
//this file was contributed by Martin Thelian
//last major change: $LastChangedDate$ by $LastChangedBy$
//Revision: $LastChangedRevision$
//
//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
package de.anomic.plasma.parser;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import de.anomic.kelondro.util.Log;
import de.anomic.plasma.plasmaParser;
import de.anomic.plasma.plasmaParserDocument;
import de.anomic.server.serverThread;
import de.anomic.yacy.yacyURL;
/**
* New classes implementing the {@link de.anomic.plasma.parser.Parser} interface
* can extend this class to inherit all functions already implemented in this class.
* @author Martin Thelian
* @version $LastChangedRevision$ / $LastChangedDate$
*/
public abstract class AbstractParser implements Parser{
/**
* a list of library names that are needed by this parser
*/
protected String[] libxDependencies = null;
/**
* the logger class that should be used by the parser module for logging
* purposes.
*/
protected Log theLogger = null;
/**
* Version number of the parser
*/
protected String parserVersionNr = "0.1";
/**
* Parser name
*/
protected String parserName = this.getClass().getName();
/**
* The source file file size in bytes if the source document was passed
* in as file
*/
protected long contentLength = -1;
/**
* The Constructor of this class.
*/
public AbstractParser(final String[] libxDependencies) {
super();
this.libxDependencies = libxDependencies;
}
/**
* Set the content length of the source file.
* This value is needed by some parsers to decide
* if the parsed text could be hold in memory
*/
public void setContentLength(final long length) {
this.contentLength = length;
}
/**
* Check if the parser was interrupted.
* @throws InterruptedException if the parser was interrupted
*/
public static final void checkInterruption() throws InterruptedException {
final Thread currentThread = Thread.currentThread();
if ((currentThread instanceof serverThread) && ((serverThread)currentThread).shutdownInProgress()) throw new InterruptedException("Shutdown in progress ...");
if (currentThread.isInterrupted()) throw new InterruptedException("Shutdown in progress ...");
}
public final File createTempFile(final String name) throws IOException {
String parserClassName = this.getClass().getName();
int idx = parserClassName.lastIndexOf(".");
if (idx != -1) {
parserClassName = parserClassName.substring(idx+1);
}
// getting the file extension
idx = name.lastIndexOf("/");
final String fileName = (idx != -1) ? name.substring(idx+1) : name;
idx = fileName.lastIndexOf(".");
final String fileExt = (idx > -1) ? fileName.substring(idx+1) : "";
// creates the temp file
final File tempFile = File.createTempFile(parserClassName + "_" + ((idx>-1)?fileName.substring(0,idx):fileName), (fileExt.length()>0)?"."+fileExt:fileExt);
return tempFile;
}
public int parseDir(final yacyURL location, final String prefix, final File dir, final plasmaParserDocument doc)
throws ParserException, InterruptedException, IOException {
if (!dir.isDirectory())
throw new ParserException("tried to parse ordinary file " + dir + " as directory", location);
final String[] files = dir.list();
int result = 0;
for (int i=0; i<files.length; i++) {
checkInterruption();
final File file = new File(dir, files[i]);
this.theLogger.logFine("parsing file " + location + "#" + file + " in archive...");
if (file.isDirectory()) {
result += parseDir(location, prefix, file, doc);
} else try {
final yacyURL url = yacyURL.newURL(location, "/" + prefix + "/"
// XXX: workaround for relative paths within document
+ file.getPath().substring(file.getPath().indexOf(File.separatorChar) + 1)
+ "/" + file.getName());
final plasmaParserDocument subdoc = new plasmaParser().parseSource(
url,
plasmaParser.getMimeTypeByFileExt(files[i].substring(files[i].indexOf('.') + 1)),
null, file);
// TODO: change anchors back to use '#' after archive name
doc.addSubDocument(subdoc);
subdoc.close();
result++;
} catch (final ParserException e) {
this.theLogger.logInfo("unable to parse file " + file + " in " + location + ", skipping");
}
}
return result;
}
/**
* Parsing a document available as byte array.
* @param location the origin of the document
* @param mimeType the mimetype of the document
* @param charset the supposed charset of the document or <code>null</code> if unkown
* @param source the content byte array
* @return a {@link plasmaParserDocument} containing the extracted plain text of the document
* and some additional metadata.
* @throws ParserException if the content could not be parsed properly
*
* @see de.anomic.plasma.parser.Parser#parse(de.anomic.net.URL, java.lang.String, byte[])
*/
public plasmaParserDocument parse(
final yacyURL location,
final String mimeType,
final String charset,
final byte[] source
) throws ParserException, InterruptedException {
ByteArrayInputStream contentInputStream = null;
try {
// convert the byte array into a stream
contentInputStream = new ByteArrayInputStream(source);
// parse the stream
return this.parse(location,mimeType,charset,contentInputStream);
} finally {
if (contentInputStream != null) {
try {
contentInputStream.close();
contentInputStream = null;
} catch (final Exception e){ /* ignore this */}
}
}
}
/**
* Parsing a document stored in a {@link File}
* @param location the origin of the document
* @param mimeType the mimetype of the document
* @param charset the supposed charset of the document or <code>null</code> if unkown
* @param sourceFile the file containing the content of the document
* @return a {@link plasmaParserDocument} containing the extracted plain text of the document
* and some additional metadata.
* @throws ParserException if the content could not be parsed properly
*
* @see de.anomic.plasma.parser.Parser#parse(de.anomic.net.URL, java.lang.String, java.io.File)
*/
public plasmaParserDocument parse(
final yacyURL location,
final String mimeType,
final String charset,
final File sourceFile
) throws ParserException, InterruptedException {
BufferedInputStream contentInputStream = null;
try {
// getting the file size of the document
this.contentLength = sourceFile.length();
// create a stream from the file
contentInputStream = new BufferedInputStream(new FileInputStream(sourceFile));
// parse the stream
return this.parse(location, mimeType, charset, contentInputStream);
} catch (final FileNotFoundException e) {
throw new ParserException("Unexpected error while parsing file. " + e.getMessage(),location);
} finally {
if (contentInputStream != null) try{contentInputStream.close();}catch(final Exception e){/* ignore this */}
}
}
/**
* Parsing a document available as {@link InputStream}
* @param location the origin of the document
* @param mimeType the mimetype of the document
* @param charset the supposed charset of the document or <code>null</code> if unkown
* @param source the {@link InputStream} containing the document content
* @return a {@link plasmaParserDocument} containing the extracted plain text of the document
* and some additional metadata.
* @throws ParserException if the content could not be parsed properly
*
* @see de.anomic.plasma.parser.Parser#parse(de.anomic.net.URL, java.lang.String, java.io.InputStream)
*/
public abstract plasmaParserDocument parse(yacyURL location, String mimeType, String charset, InputStream source) throws ParserException, InterruptedException;
/**
* @return Returns a list of library names that are needed by this parser
* @see de.anomic.plasma.parser.Parser#getLibxDependences()
*/
public String[] getLibxDependences() {
return this.libxDependencies;
}
/**
* Setting the logger that should be used by this parser class ...
*/
public void setLogger(final Log log) {
this.theLogger = log;
}
/**
* Returns the version number of the parser
* @return parser version number
*/
public String getVersion() {
return this.parserVersionNr;
}
/**
* Return the name of the parser
*/
public String getName() {
return this.parserName;
}
public void reset() {
this.contentLength = -1;
}
}