我使用以下代码:
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import org.apache.log4j.Logger;
import com.zjswkj.analyser.ddao.LogEntryDao;
import com.zjswkj.analyser.model.LogEntry;
import com.zjswkj.analyser.parser.LogParser;
public class ListenTest {
private RandomAccessFile raf;
private long lastPosition;
private String logEntryPattern = "^([\\d.]+) (\\S+) (\\S+) \\[([\\w:/]+\\s[+\\-]\\d{4})\\] \"(.+?)\" (\\d{3}) (\\S+) \"([^\"]+)\" \"([^\"]+)\"";
private static Logger log = Logger.getLogger(ListenTest.class);
public void startListenLogOfCurrentDay() {
try {
if (raf == null)
raf = new RandomAccessFile(
"/tmp/logs/localhost_access_log.2010-12-20.txt",
"r");
String line;
while (true) {
raf.seek(lastPosition);
while ((line = raf.readLine()) != null) {
if (!line.matches(logEntryPattern)) {
// not a complete line,roll back
lastPosition = raf.getFilePointer() - line.getBytes().length;
log.debug("roll back:" + line.getBytes().length + " bytes");
if (line.equals(""))
continue;
log.warn("broken line:[" + line + "]");
Thread.sleep(2000);
} else {
// save it
LogEntry le = LogParser.parseLog(line);
LogEntryDao.saveLogEntry(le);
lastPosition = raf.getFilePointer();
}
}
}
} catch (FileNotFoundException e) {
log.error("can not find log file of today");
} catch (IOException e) {
log.error("IO Exception:" + e.getMessage());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new ListenTest().startListenLogOfCurrentDay();
}
}
现在,我的问题是,如果正在写入文件的新行没有完成,就会发生死循环。
例如,如果Tomcat试图向文件写入一个新行:
10.33.2.45 - - [08/Dec/2010:08:44:43 +0800] "GET /poi.txt HTTP/1.1" 200 672 "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8"
当只写入行的一部分时(例如:<10.33.2.45 - - [08/Dec/2010:08:44:43 +0800] "GET /poi.txt HTTP/1.1" 200 672>),现在由于它无法匹配我定义的模式,也就是说,tomcat没有完成它的写作,所以我将尝试回滚文件指针,并休眠2秒,然后再次读取。
在休眠期间,可能还没有写入行的最后一部分(实际上我进行测试时是自己写的而不是tomcat),我认为,随机访问文件将读取一个可以匹配模式的新行,但事实并非如此。
有人能检查一下代码吗?
注意:日志文件的格式是“combined”格式的:
10.33.2.45 - - [08/Dec/2010:08:44:43 +0800] "GET /poi.txt HTTP/1.1" 200 672 "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8"