String Conversion....

Hello,

I am stuck on this project that is supposed to accept a test file as an input, reverse the text (ex: Hello there!....!ereht olleH) and then output to another file. So if I run this program using the second file as an input, then text comes back to normal. There are two classes - ReverseLine and a ReverseLineTester.
I have tried to compile it and I get the error message:

1 error found:
File: C:\Documents and Settings\desktop\Java Excercises\Reverse Line\ReverseLineTester.java [line: 26]
Error: C:\Documents and Settings\desktop\Java Excercises\Reverse Line\ReverseLineTester.java:26: cannot find symbol
symbol : method reverseLine(java.lang.String)
location: class ReverseLineTester


Here is what I have so far:

Code:

---

import java.io.FileReader;
import java.io.PrintWriter;
import java.io.FileNotFoundException;
import java.util.Scanner;



public class ReverseLineTester
{
 
  public static void main(String[] args)
  {
   
  try
  {
    for (int i = 1; i < args.length; i++)
    {
      FileReader reader = new FileReader(args[i]);
      Scanner in = new Scanner(reader);
      PrintWriter out = new PrintWriter("File_2.txt");
      int lineNumber = 1;
     
      while (in.hasNextLine())
      {
        String line = in.nextLine();
        System.out.print(reverseLine(line));
        lineNumber++;
      }
    }
  }
 
  catch (FileNotFoundException ex)
  {
    System.out.print("File not found!");
  }
   
   
  }
 
 
 
}

---

Code:

---

public class ReverseLine
{
  private String line;
 
  public ReverseLine()
  {
  }
 
 
  public ReverseLine(String myline)
  {
    line = myline;
  }
 
  public String reverseLine(String str)
  {
    StringBuffer buffer = new StringBuffer(str);
    buffer = buffer.reverse();
    String reverseString = buffer.toString();
    return reverseString;
  }
 
 
}

---

Look at this statement,

Code:

---

System.out.print(reverseLine(line));

---

You are referring that method in wrong way. reverseLine() method is not in the ReverseLineTester class, it's on other class. To access that you need an instance to the class.

• What is the number of arguments that your program is receiving? Because if it's just one input file name, then nothing is going to happen:

Code:

---

for (int i = 1; i < args.length; i++)

---

The compare condition would be 1<1 and the for loop would not execute. To avoid this, change the initial variable assignment to int i = 0.

• Another question... what is the for loop for?

Luck,
CJSL

Oh, man, I see it now!
Thanks!
How is my ReverseLine class looking?

Yes, that's true. I don't think I need a loop here.
Program supposed to run from the CLI (ex: ReverseLineTester File_1)
So I probably should get rid of "for" line and change

FileReader reader = new FileReader(args[i]);
to
FileReader reader = new FileReader(args[1]);

Remember, arrays are index based, which means that their first element is 0 (args is nothing but an array). Therefore if you only have one argument it should be referenced as args[0], not args[1] (which would be the second element of the array).

Luck,
CJSL

<CODE>import java.io.FileReader;
import java.io.PrintWriter;
import java.io.FileNotFoundException;
import java.util.Scanner;



public class ReverseLineTester
{

public static void main(String[] args)
{

try
{
String rline = "";
FileReader fileIn = new FileReader(args[0]);
Scanner in = new Scanner(fileIn);
PrintWriter fileOut = new PrintWriter("File_2.txt");
ReverseLine rn = new ReverseLine(rline);
int lineNumber = 1;

while (in.hasNextLine())
{
String line = in.nextLine();
rn.reverseLine(line);
fileOut.print(line);
lineNumber++;
}

}

catch (FileNotFoundException ex)
{
System.out.print("File not found!");
}


}



}</CODE>

Is this the way to go?

I'm assuming that you haven't finished the program because you have a variable, lineNumber, that's defined (wrongly defined) but isn't used. So... the questions is:

• Does the program work? ...does it do what you want it to do?

CJSL

Your assumptions are correct - it does not.
It compiles, but does not create the second file with the text backwards (File_2.txt)

I thought lineNumber is sort of a counter to go through the file line by line...

Could you also tell me if ReverseLine class is all right?

Thanks!