/*
* Licensed under the GPL License. You may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
*
* THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
package com.googlecode.psiprobe.controllers.logs;
import com.googlecode.psiprobe.tools.BackwardsFileStream;
import com.googlecode.psiprobe.tools.BackwardsLineReader;
import com.googlecode.psiprobe.tools.logging.LogDestination;
import java.io.File;
import java.util.LinkedList;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.servlet.ModelAndView;
public class FollowController extends LogHandlerController {
protected ModelAndView handleLogFile(HttpServletRequest request, HttpServletResponse response, LogDestination logDest) throws Exception {
ModelAndView mv = new ModelAndView(getViewName());
File file = logDest.getFile();
if (file.exists()) {
LinkedList lines = new LinkedList();
long actualLength = file.length();
long lastKnownLength = ServletRequestUtils.getLongParameter(request, "lastKnownLength", 0);
long currentLength = ServletRequestUtils.getLongParameter(request, "currentLength", actualLength);
long maxReadLines = ServletRequestUtils.getLongParameter(request, "maxReadLines", 0);
if (lastKnownLength > currentLength
|| lastKnownLength > actualLength
|| currentLength > actualLength) {
//
// file length got reset
//
lastKnownLength = 0;
lines.add(" ------------- THE FILE HAS BEEN TRUNCATED --------------");
}
BackwardsFileStream bfs = new BackwardsFileStream(file, currentLength);
try {
BackwardsLineReader br = new BackwardsLineReader(bfs);
long readSize = 0;
long totalReadSize = currentLength - lastKnownLength;
String s;
while (readSize < totalReadSize && (s = br.readLine()) != null) {
if (!s.equals("")){
lines.addFirst(s);
readSize += s.length();
} else {
readSize++;
}
if (maxReadLines != 0 && lines.size() >= maxReadLines) {
break;
}
}
if (lastKnownLength != 0 && readSize > totalReadSize) {
lines.removeFirst();
}
} finally {
bfs.close();
}
mv.addObject("lines", lines);
}
return mv;
}
}