Unexpected result in efficieny comparson of Hashtable and ArrarList

Question

i have been told that Hashtable is much more efficient than ArrayList. To convince my self I did the follwing:
a) created a file of 100000 random 3 letter strings from acii range of 65 to 122. Foll. is the code I used.
import java.util.Random;
import java.io.*;
class RandomStrToFile {
     public static void main(String[] args) {
          Random rnd = new Random();
          long i,imax=100000;
          char cNL;
          String sFileName = "myrandom_strings.txt";
          String sBuffer="";
          try {
          FileWriter fw = new FileWriter(sFileName);
          BufferedWriter bw = new BufferedWriter(fw);
          for (i=0; i<imax;i++){
               sBuffer=""+ (char) (65 + (int)((rnd.nextDouble())*57)) + (char) (65 + (int)((rnd.nextDouble())*57)) + (char) (65 + (int)((rnd.nextDouble())*57));
               bw.write(sBuffer);
               bw.newLine();
               //System.out.println(sBuffer);
          bw.close();
          fw.close();
          } catch (IOException e) {}
b. Timed to create a unique valielist from the above file, uing ArrayList and Hashtable respectively. Following is my code:
import java.io.*;
import java.util.*;
public class test2 {
     public static void main(String[] args){
          String sLine;
          int iVal;
          long startTime, endTime;
          ArrayList<String> al = new ArrayList<String>();
          Hashtable ht = new Hashtable (4999); // use a prime number
          try {
               FileReader fr = new FileReader("C:\\Home\\MyJava\\eclipse_proj\\MyFirst\\bin\\myrandom_strings.txt");
               BufferedReader br = new BufferedReader(fr);
               startTime = System.currentTimeMillis();
               iVal=0;
               while ((sLine=br.readLine())!=null){
                    //System.out.println(sLine);
                    iVal=iVal+1;
                    if (!ht.contains(sLine)){
                         ht.put(iVal,sLine);
                         //System.out.println(sLine);
               endTime = System.currentTimeMillis();
               System.out.println("The Hashtable Elapsed Time is: " + (startTime-endTime));
               br.close();
               fr.close();
               fr = new FileReader("C:\\Home\\MyJava\\eclipse_proj\\MyFirst\\bin\\myrandom_strings.txt");
               br = new BufferedReader(fr);
               startTime = System.currentTimeMillis();
               iVal=0;
               while ((sLine=br.readLine())!=null){
                    //System.out.println(sLine);
                    iVal=iVal+1;
                    if (!al.contains(sLine)){
                         al.add(sLine);
                         //System.out.println(sLine);
               endTime = System.currentTimeMillis();
               System.out.println("The ArrayList Elapsed Time is: " + (endTime-startTime));
               br.close();
               fr.close();
          } catch (IOException e){}
To my surprize Hashtable approach was much slower thatn the ArrayList approach. Am I missing something here?

Answer 1

////////////////////////////////////////datafile creation code///////////////////////////////
import java.util.Random;
import java.io.*;
class RandomStrToFile {
     public static void main(String[] args) {
          Random rnd = new Random();
          long i,imax=100000;
          char cNL;
          String sFileName = "myrandom_strings.txt";
          String sBuffer="";
          try {
          FileWriter fw = new FileWriter(sFileName);
          BufferedWriter bw = new BufferedWriter(fw);
          for (i=0; i<imax;i++){
               sBuffer=""+ (char) (65 + (int)((rnd.nextDouble())*57)) + (char) (65 + (int)((rnd.nextDouble())*57)) + (char) (65 + (int)((rnd.nextDouble())*57));
               bw.write(sBuffer);
               bw.newLine();
               //System.out.println(sBuffer);
          bw.close();
          fw.close();
          } catch (IOException e) {}
}////////////////////////////////Testing code//////////////////////////////////
import java.io.*;
import java.util.*;
public class test2 {
     public static void main(String[] args){
          String sLine;
          int iVal;
          long startTime, endTime;
          ArrayList<String> al = new ArrayList<String>();
          Hashtable ht = new  Hashtable (4999); // use a prime number
          try {
               FileReader fr = new FileReader("C:\\Home\\MyJava\\eclipse_proj\\MyFirst\\bin\\myrandom_strings.txt");
               BufferedReader br = new BufferedReader(fr);
               startTime = System.currentTimeMillis();
               iVal=0;
               while ((sLine=br.readLine())!=null){
                    //System.out.println(sLine);
                    iVal=iVal+1;
                    if (!ht.contains(sLine)){
                         ht.put(iVal,sLine);
                         //System.out.println(sLine);
               endTime = System.currentTimeMillis();
               System.out.println("The Hashtable Elapsed Time is: " + (startTime-endTime));
               br.close();
               fr.close();
               fr = new FileReader("C:\\Home\\MyJava\\eclipse_proj\\MyFirst\\bin\\myrandom_strings.txt");
               br = new BufferedReader(fr);
               startTime = System.currentTimeMillis();
               iVal=0;
               while ((sLine=br.readLine())!=null){
                    //System.out.println(sLine);
                    iVal=iVal+1;
                    if (!al.contains(sLine)){
                         al.add(sLine);
                         //System.out.println(sLine);
               endTime = System.currentTimeMillis();
               System.out.println("The ArrayList Elapsed Time is: " + (endTime-startTime));
               br.close();
               fr.close();
          } catch (IOException e){}
}OK here we go. I cannot get rid of the file as taht is where I put the strings. See wheter you can find the issue.