Re: Need character output instead of numbers
bilsch wrote:
Here is a simple example of reading a text file as integers and
Strictly speaking, you can only read a text file as text, then convert (som=
e of) that text to an integer.
displaying each with blank spaces in between.
> import java.io.*;
>
> public class Nvj3 {
>
> public static void main(String[] args){
> try {
> FileInputStream file = new FileInputStream("NVRAM.TXT");
> boolean eof = false;
> int count = 0;
> while (!eof) {
> int input = file.read();
> System.out.print(input + " ");
> if (input == -1)
> eof = true;
> else
> count++;
>
>
> }
> System.out.println("Bytes read : " + count);
>
> } catch (IOException e){
> System.out.println("Could not read file");
> }
>
> }
> }
>
OUTPUT is positive integers less than 128 (ASCII):
78 86 82 65 77 44 32 86 101 114 115 105 111 110 32 49 46 50 48 13 10
78 111 110 45 86 111 108 97 116 105 108 101 32 82 65 77 32 83 121 115
I looked at the input file with a hex editor and the ASCII chars are all=
stored as bytes - not integers.
Right.
I HAVE TWO QUESTIONS: the statement: int input = file.read();
reads the file as a bunch of integer type values but the output is in
character type. It seems like the correct input statement would be:
char input = file.read();
Nope. Read the Javadocs for that method, and you can clearly see that the r=
eturn type is 'int'.
I tried that and it is an error. QUESTION 1): Can someone explain why
the file is read as char type but the statement says int type?
First of all, your question is not valid. Nothing is read from any 'InputSt=
ream' as a 'char'. That only happens with 'Reader' types. 'InputStream#read=
()' returns values from zero to 255, inclusive, corresponding to the bytes =
in the file, until EOF when it returns -1.
<http://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read()>
Read the Javadocs. Also the part of Roedy's response that explains: "Note h=
ow read() reads one unsigned byte but returns an int so that is can use -1 =
as an eof marker." That is a restatement of what's in the Javadocs, so real=
ly you should read the Javadocs.
QUESTION 2) What do I need to do to get ASCII characters as output
instead of numbers?
ASCII characters *are* numbers.
What do you really want to do?
I'd do something like:
BufferedReader reader = new BufferedReader(new FileReader("NVRAM.TXT"));=
and use its methods to return 'String' values directly, but if I were count=
ing bytes read, as you seem to want, I'd do basically what you already did.
You can also convert byte arrays to 'String' values if you use other API me=
thods and are very, very rigorous about character encoding. Are you?
--
Lew