Trying to create log of programs activities

Question

Trying to create a log file that will track what my program is doing but receiving the following error message on my write command:
C:\jakarta-tomcat-4.0.3\webapps\webdav\WEB-INF\classes>javac ReadSource.java
ReadSource.java:28: cannot resolve symbol
symbol : method write (java.lang.String)
location: class java.io.FileOutputStream
fos.write(s);
^
1 error
Here is my program:
import java.io.*;
import java.util.StringTokenizer;
import java.sql.*;
public class ReadSource {
static String filename = "C:/upload/log/logfil.log";
public static void main(String[] args) throws Exception {
     StringTokenizer st1;
          String val1, val3, val4, val5, val9, val10, val11, val12, val13, val14, val16;
          String val2, val6, val7, val8, val15, val17;
          File f = new File("C://upload" );
     try {
          Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@xxxx.xxxxx.xxxx:1521:xx","xxxxxx","xxxxx");
                    Statement st = conn.createStatement();
                    File fl = new File(filename);
                    if (!fl.exists())
                    { fl.createNewFile(); }
                    FileOutputStream fos = new FileOutputStream(fl.toString(),true);
                    if (f.isDirectory())
                    { String [] s = f.list();
                    for (int i=0; i<s.length; i++)
                    { System.out.println(s[i]);
                         fos.write(s[i]);
                         System.out.println(f);
                              System.out.println(f+"/"+s[i]);
          FileReader file = new FileReader(f+"/"+s[i]);
                              File inputFile = new File(f+"/"+s[i]);
                              File outputFile = new File("C:/upload/archive/"+s[i]);
                    BufferedReader buff = new BufferedReader(file);
                    boolean eof = false;
                    String val0="";
                    ResultSet rec = st.executeQuery("SELECT landings_hold_batch_seq.nextval FROM dual");
                    while(rec.next())
                    { val0 = rec.getString(1);
                         //System.out.println(val0);
                    while (!eof)
                    { String line = buff.readLine();
                         if (line == null)
                         { eof = true; }
                         else
                         { //System.out.println(line);
                              st1 = new StringTokenizer(line,",");
                                   //System.out.println(val0);
                                   val1 = st1.nextToken();
                                   val2 = st1.nextToken();
                                   val3 = st1.nextToken();
                                   val4 = st1.nextToken();
                                   val5 = st1.nextToken();
                                   val6 = st1.nextToken();
                                   val7 = st1.nextToken();
                                   val8 = st1.nextToken();
                                   val9 = st1.nextToken();
                                   val10 = st1.nextToken();
                                   val11 = st1.nextToken();
                                   val12 = st1.nextToken();
                                   val13 = st1.nextToken();
                                   val14 = st1.nextToken();
                                   val15 = st1.nextToken();
                                   val16 = st1.nextToken();
                                   val17 = st1.nextToken();
                                   /*System.out.println("Token 0: " + val0);
                              System.out.println("Token 1: " + val1);
                              System.out.println("Token 2: " + val2);
                                   System.out.println("Token 3: " + val3);
                                   System.out.println("Token 4: " + val4);
                                   System.out.println("Token 5: " + val5);
                                   System.out.println("Token 6: " + val6);
                                   System.out.println("Token 7: " + val7);
                                   System.out.println("Token 8: " + val8);
                                   System.out.println("Token 9: " + val9);
                                   System.out.println("Token 10: " + val10);
                                   System.out.println("Token 11: " + val11);
                                   System.out.println("Token 12: " + val12);
                                   System.out.println("Token 13: " + val13);
                                   System.out.println("Token 14: " + val14);
                                   System.out.println("Token 15: " + val15);
                                   System.out.println("Token 16: " + val16);
                                   System.out.println("Token 17: " + val17);*/
                                   st.executeUpdate("INSERT INTO LANDINGS_HOLD (lh_id, lh_batch, supplier_dr_id, supplier_unique_id, supplier_dealer_id, supplier_cf_id, supplier_vessel_id, unload_year, unload_month, unload_day, state_code, county_code, port_code, itis_code, market, grade, reported_quantity, unit_measure, dollars, lh_loaddt, lh_loadlive)" +
                    "VALUES (0,'"+val0+"','"+val1+"',"+val2+",'"+val3+"','"+val4+"','"+val5+"',"+val6+","+val7+","+val8+",'"+val9+"','"+val10+"','"+val11+"','"+val12+"','"+val13+"','"+val14+"',"+val15+",'"+val16+"',"+val17+",SYSDATE,NULL)");
                         FileReader in = new FileReader(inputFile);
                         FileWriter out = new FileWriter(outputFile);
int c;
                         while ((c = in.read()) != -1)
                         { out.write((char)c); }
                         in.close();
                         out.close();
                         //f.delete(); // delete the upload file
                         buff.close();
                    conn.close();
                    else
                    { System.out.println("No files to process"); }
          catch(Exception e) { System.out.println("My Error: " + e); }

Answer 1

Code's too badly formatted to read, but logging is considered an old chestnut these days anyway:
If you're using JDK 1.4, use the java.util.logging package http://java.sun.com/j2se/1.4.1/docs/api/java/util/logging/package-summary.html
If you're using JDK 1.3 or earlir, use Apache log4j http://jakarta.apache.org/log4j/docs/index.html
If you have to run in both old a new VMs, use log4j.