Write a program that consists of three classes. The first class will be the actu

Question

Write a program that consists of three classes. The first class will be the actual program.

The second class will simply convert a string to lower case.

The third class will have three methods:

public static String trimmed(String str)

public static String trimmed(String str, int len)

public static String squeeze(String str)

The 1st trimmed method will return str without leading or trailing whitespace and will return an empty string if str is null.

The 2nd trimmed method will return the first len characters after trimming the string. The 2nd method must make use of the 1st method.

The squeeze method will replace all sequences of 2 spaces with 1 space.

The program will read a file containing the data below (cut and paste it into notepad and save it), and will display each line:

as entered but trimmed and squeezed.
as entered but trimmed, squeezed, and shortened to 10 characters
as entered but trimmed, squeezed, converted to lower case, and shortened to 20 characters.

Data (copy after this line down to (not including) the line that says end data, you will have 5 lines):

     This is a test, this is only a test!
This    test    is    a    test   of    your   Java   programming   skills!
xyz
ABCDEFGHIJKLMONPQRSTUVWXYZ1234567890-=_+                         !
end data

Explanation / Answer

import java.io.*;
import java.util.*;

class Convert{
  
   public static String   convertToUpperCase(String str){
          return str.toUpperCase();
   }
}

class SM {
      public static String trimmed(String str){
           int begin=-1,end = -1;

           if (str == null)
              return "";
           for (int i = 0; i<str.length(); i++){
               if (str.charAt(i) != ' '){
                    begin = i;
                    break;
               }
           }
           for (int i = str.length()-1; i>=0; i--){
               if (str.charAt(i) != ' '){
                    end=i+1;
                    break;
               }
           }
           return (str.substring(begin,end));

      }
      public static String trimmed(String str, int len){
           if (str.length() > 20)
              str = str.substring(0,len);
           str = trimmed(str);
           return (str);

      }
      public static String squeeze(String str){
         return str.replaceAll(" ", " ");
      }  
}

public class DemoString{
    public static void main(String args[]){
        try {

            File file = new File("input13.txt");
            FileReader fileReader = new FileReader(file);
            BufferedReader bufferedReader = new BufferedReader(fileReader);
            String line;
           
            while ((line = bufferedReader.readLine()) != null) {
                 System.out.println(SM.squeeze(SM.trimmed(line)));
                 System.out.println(SM.trimmed(SM.squeeze(SM.trimmed(line)),10));
                 System.out.println(SM.trimmed(Convert.convertToUpperCase(SM.squeeze(SM.trimmed(line))),20));
            }
           
            fileReader.close();
        }catch (IOException e) {
     e.printStackTrace();
        }
    }

}

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