Please help me on this palindrome program

[avelin chen]

import java.io.*;
 
public class lab16b2
{
 
public static void main (String args[]) throws IOException
{   
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
boolean finished = false;
clearScreen(31);

do
{
System.out.print("Enter a string  ===>>  ");
Palindrome p = new Palindrome(input.readLine());        

p.displayData();
System.out.print("\nDo you wish to repeat this program [Y/N]?  ===>>  ");
String repeat=input.readLine();
      boolean right=(repeat.equals("Y") || repeat.equals("yes")||repeat.equals("y")||repeat.equals("YES"));
      if (right)
{

   System.out.println(); 
}
else 
{
System.out.println();
   finished = true;
}
}
while (!finished); 

}
public static void clearScreen(int numberoflines)
 {
  for(int i=0;i<numberoflines;i++)
  System.out.println();
}
}
  
 
class Palindrome
{
   private String s1;// stores original string entered at the keyboard
   private String s2;// stores s1 with punctuation and spaces removed
   private boolean palindrome;
   private boolean almostPalindrome;
 
 
 
   private boolean isPal(String s)
   {
   System.out.println("String:" + s1);
   s2=s1.toLowerCase();
   
   int a=0;
    int b=s2.length()-1;
 
    while (a><b)
    {
      if(s2.charAt(a) != s2.charAt(b))
      {
   
        return false;
      }
      a++;
      b--;
    }
   
    return true; 
  }
 
 
   private boolean isAlmostPal()
   {
   s2=s1.toLowerCase();
   s2=s2.replaceAll("[^a-zA-Z0-9]+", "");
  
    int a=0;
    int b=s2.length()-1;
 
    while (a><b)
    {
    
      if(s2.charAt(a) != s2.charAt(b))
      {
   
        return false;
      }
      a++;
      b--;
    }
   
   return true; 
  }
  
 
   public void checkData()
  {
  if(isPal(s1)==true)
  {
  almostPalindrome=false;
  }
  else
 almostPalindrome=true;
 
  }
  
  
   public Palindrome(String s)
   {
   s1=s;
   s2="";
   }
   
  
   public void displayData()
   {
   
    if (isPal(s2))
   {
      System.out.println("Palindrome: true");
    }
    else
    {
    
      System.out.println("Palindrome: false");
    }
    
    if(isAlmostPal())
     {
      System.out.println("Almost Palindrome: true");
   
    }
    else
    {
    
      System.out.println("Almost Palindrome: false");
    
    }
    
  
    
   
    
  }
  
 
 
 
  }
 

The output is supposed to be:

Enter a string ===>> Racecar

String: Racecar
Palindrome: true
Almost Palindrome: false

Do you wish to repeat this program [Y/N]? ===>> y

Enter a string ===>> Aardvark

String: Aardvark
Palindrome: false
Almost Palindrome: false

Do you wish to repeat this program [Y/N]? ===>> y

Enter a string ===>> A man, a plan, a canal, Panama

String: A man, a plan, a canal, Panama
Palindrome: false
Almost Palindrome: true

Do you wish to repeat this program [Y/N]? ===>> n

While on the other hand, my output is:
Enter a string ===>> Racecar

String: Racecar
Palindrome: true
Almost Palindrome: true<--SUPPOSED TO BE FALSE

Do you wish to repeat this program [Y/N]? ===>> y

Enter a string ===>> Aardvark

String: Aardvark
Palindrome: false
Almost Palindrome: false

Do you wish to repeat this program [Y/N]? ===>> y

Enter a string ===>> A man, a plan, a canal, Panama

String: A man, a plan, a canal, Panama
Palindrome: false
Almost Palindrome: true

Do you wish to repeat this program [Y/N]? ===>> n

I don't know how to change it without altering the other palindromes. Help will be greatly appreciated!

[Christophe Verré]

Do you call checkData() anywhere ?

[Layne Lund]

Perhaps isAlmostPal() should call isPal() first to determine if it is a true palindrome. What can you do with this result to return the value you expect?

Also, you don't need all the if...else statements for your output. Instead you can print the output in a single line:

System.out.println("Palindrome: " + isPal(s));

[Adam Price]

Originally posted by avelin chen:

import java.io.*;
 
[B]While on the other hand, my output is:[/B]
Enter a string ===>> Racecar
 
String: Racecar
Palindrome: true
Almost Palindrome: true<--SUPPOSED TO BE FALSE
 .
.
.
I don't know how to change it without altering the other palindromes. Help will be greatly appreciated![/quote]
 
In your other [surl='https://coderanch.com/t/674455/Thread-Boost-feature' class='api' title='more about the thread boost feature on coderanch.com']thread[/surl], I said:
 [quote]
Is it true that (by your definition) any true palindrome is not an almostpalindrome? If so, why not just include a check against true palindrome? ie:
[CODE]
  private boolean isAlmostPal()
   {
     if ( !isPal(s1) ) {
          return false
     }
     else {  
      your existing code } 
 

Maybe I am not understanding what the criteria are?

You want anything that is a Palindrome to fail at being an almost palindrome, right? Run that check first - if it passes isPal, it should return false for isAlmostPal.