LogReaderT1.java

import java.io.*;
import java.util.regex.*;
import java.util.Date;
import java.util.ArrayList;

public class LogReaderT1 {

    void runTest(String fileName){
        ArrayList<String> logRecords=new ArrayList<String>();
        BufferedReader br;
        String nextRec;
        long start,end;

        start=System.currentTimeMillis();

        try {
            br = new BufferedReader(new FileReader(fileName));
            while( (nextRec=br.readLine()) != null){
                logRecords.add(nextRec);
            }
            br.close();
        } catch(IOException ex) {

        } finally {
        }

        end=System.currentTimeMillis();
        System.out.println(logRecords.size());
        System.out.println("Elapsed time: "+(end-start)+"ms");

        int n1=0;
        int n2=0;

        start=System.currentTimeMillis();
        Pattern pat=Pattern.compile("^(.{11})\\s(\\d\\d:\\d\\d:\\d\\d)\\s(\\S+)\\s(\\w+\\.\\w+)\\s(\\w+):\\s+(ACCEPT|REJECT|DROP)\\s+(.*$)" );
        for(String s: logRecords){
            Matcher mat=pat.matcher(s);
            if(mat.matches()){
                n1++;
            } else {
                n2++;
            }
        }
        System.out.println("Known:"+n1+"  unknown:"+n2);
        end=System.currentTimeMillis();
        System.out.println("Elapsed time: "+(end-start)+"ms");

    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        LogReaderT1 l=new LogReaderT1();
        l.runTest("/home/haazee/kern.log");
    }

}