BlueJ Program On String Manipulation

 This is a menu driven program with string manipulation.

import java.io.*;
 class String1
 {
     String s1,s2;  
     BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
    private void takeName() throws IOException
    {
        System.out.print("\nEnter Name: ");
        s1=br.readLine();
    }
    private void wordCaseName()
    {
      char ch;
      s2="";
      int i,len;
      len=s1.length();
      for(i=0;i<len;i++)
      {
        ch=s1.charAt(i);
        if(i==0)
        s2=s2+Character.toUpperCase(ch);
        else if(ch==' ')
        {
            s2=s2+" ";
        s2=s2+Character.toUpperCase(s1.charAt(i+1));
        i++;
    }
    else
    s2=s2+Character.toLowerCase(ch);
}
s1=s2;
System.out.println("\nName in Sentence Case: "+s1);
}
    private void shortName()
    {
      char ch;
      s2="";
      int i,len,sp=0;
      len=s1.length();
      for(i=0;i<len;i++)
      {
          if(s1.charAt(i)==' ')
          sp++;
        }
           
      for(i=0;i<len;i++)
      {
        ch=s1.charAt(i);
        if(i==0)
        s2=s2+Character.toUpperCase(ch)+".";
        else if(ch==' ' && sp!=1)
        {
            s2=s2+" ";
        s2=s2+Character.toUpperCase(s1.charAt(i+1))+".";
        i++;
        sp--;
    }
    else if(ch==' ' && sp==1)
        {
            s2=s2+" ";
        s2=s2+Character.toUpperCase(s1.charAt(i+1));
        i++;
        sp--;
    }
    else if(sp==0)
    s2=s2+Character.toLowerCase(ch);
}
System.out.println("\nName in Short Form: "+s2);
}    
  private void replaceWord() throws IOException
  {
      String str1,str2,s3,s4;
      int i;
      s2="";
      s3=s1.trim()+" ";
      System.out.print("\nEnter the word which is to be replaced: ");
      str1=br.readLine();
      System.out.print("\nEnter the word which will replace: ");
      str2=br.readLine();
      while(true)
      {
           i=s3.indexOf(' ');
           if(i<0)
           break;
           s4=s3.substring(0,i);
           s3=s3.substring(i+1);
           if(s4.equalsIgnoreCase(str1))
           s2=s2+" "+str2;
           else
           s2=s2+" "+s4;
        }
        s2=s2.trim();
        System.out.println("\nModified Name: "+s2);
           
    }
    private void surnameFirst()
  {
      String s3,s4;
      int i;
      s2="";
      s3=s1;
      i=s3.lastIndexOf(' ');
      s2=s2+s3.substring(i+1);
      s3=s3.substring(0,i)+ " ";
      while(true)
      {
           i=s3.indexOf(' ');
           if(i<0)
           break;
           
           s2=s2+" "+s3.substring(0,i);;
           s3=s3.substring(i+1);
        }
        s2=s2.trim();
        System.out.println("\nModified Name With Surname First: "+s2);
    }
        public static void main(String args[])throws IOException
        {
            int choice=1;
            boolean bool=true;
            String parts1, parts2, parts3;
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String1 ob=new String1();
            ob.takeName();
             while(choice!=0)
            {
                System.out.println("Enter 1 to view Name In Sentence Case\n 2 to view Name in Short Form\n 3 To replace a Word with Another\n 4 To Display Surname First and Then Name\n 0 For Exit: ");
                choice=Integer.parseInt(br.readLine());
                switch(choice)
                {
                     case 1:
                     ob.wordCaseName();
                     break;
                     case 2:
                     ob.shortName();
                     break;
                     case 3:
                     ob.replaceWord();
                     break;
                     case 4:
                     ob.surnameFirst();
                     break;
                     case 0:
                     System.out.print("\nEnd of Program.");
                     break;
                     default:
                     System.out.print("\nWrong Choice.");
                    }
                }
            }
        }
                

           Sample Input Output

Enter Name: amal KANTI maZUMder
Enter 1 to view Name In Sentence Case
 2 to view Name in Short Form
 3 To replace a Word with Another
 4 To Display Surname First and Then Name
 0 For Exit: 
1

Name in Sentence Case: Amal Kanti Mazumder
Enter 1 to view Name In Sentence Case
 2 to view Name in Short Form
 3 To replace a Word with Another
 4 To Display Surname First and Then Name
 0 For Exit: 
2

Name in Short Form: A. K. Mazumder
Enter 1 to view Name In Sentence Case
 2 to view Name in Short Form
 3 To replace a Word with Another
 4 To Display Surname First and Then Name
 0 For Exit: 
3

Enter the word which is to be replaced: Kanti
Enter the word which will replace: Kumar
Modified Name: Amal Kumar Mazumder
Enter 1 to view Name In Sentence Case
 2 to view Name in Short Form
 3 To replace a Word with Another
 4 To Display Surname First and Then Name
 0 For Exit: 
4

Modified Name With Surname First: Mazumder Amal Kanti
Enter 1 to view Name In Sentence Case
 2 to view Name in Short Form
 3 To replace a Word with Another
 4 To Display Surname First and Then Name
 0 For Exit: 
0