java PrintWriter object doesn't fill file

Question

PrintWriter object doesn't write lines into out.txt file, however creates it.

reading from BufferedReader object works fine.

package extractcdr;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ExtractCDR {

public static void main(String[] args) throws FileNotFoundException, IOException {

    BufferedReader brnew BufferedReader(new FileReader("in.txt"));
    PrintWriter pw=ew PrintWriter(new FileWriter("out.txt"));

    int t=0;
    String line;
    String[] lines=new String[t+1];
    String interf;
    String date;
    String duration;
    Pattern pattern_date=Pattern.compile("\\w+\\s:\\s\\w+\\s(\\d\\d:\\d\\d:\\d\\d).{13}(\\w{3}\\s\\d+\\s\\d+)");
    Pattern pattern_duration=Pattern.compile("\\s\\w{3}\\s(\\d\\d:\\d\\d:\\d\\d)");
    Pattern pattern_interf=Pattern.compile("\\s\\w+\\s(\\d\\/\\d\\/*\\d*:\\d\\d)");

    Matcher matcher;

        while((line=br.readLine())!=null)
        {
            lines[t]=line;
            lines=Arrays.copyOf(lines, lines.length+1);

            if(lines[t].contains("Telephony"))
            {
                matcher=pattern_date.matcher(lines[t-2]);
                if(matcher.find())
                {
                    date=matcher.group(1)+" "+matcher.group(2);
                    System.out.println(date);
                    pw.println(date);
                }

                matcher=pattern_duration.matcher(lines[t-1]);
                if(matcher.find())
                {
                    duration=matcher.group(1);
                    System.out.println(duration);
                    pw.println(duration);
                }

                matcher=pattern_interf.matcher(lines[t]);
                if(matcher.find())
                {
                    interf=matcher.group(1);
                    System.out.println(interf);
                    System.out.println();
                    pw.println(interf);
                    pw.println("\n");
                }
            }

            t++;

        }
}
}

On standard output I can see with out.printline that content is correctly grabbed and processed but nothing is the out.txt file.