byte array to string

Question

Hello guys!

have small problem, and would very much appreciate help :)

I should convert byte array to string and get this output string: “[0, 0, 0, 0]” After that another method should take the string as input and retrieve the byte array from the first one.

Im getting error that i have number.format exception, so i guess i should make convertToString method in some other way. This is what i have so far:

import java.io.ByteArrayOutputStream;
import java.util.StringTokenizer;


public class byteToString {

    public String convertToString(){
     byte[] byteArray = new byte[] {91,79,44,32,79,44,32,79,44,32,79,93};  
     String holder = new String(byteArray);
     return holder;

    }
    /*was told to use this code to convert back*/
     private static byte[] toByteArray(String myString){
     myString = myString.substring(0, myString.length()- 1).substring(1);
     ByteArrayOutputStream myStream = new ByteArrayOutputStream();
     for (StringTokenizer myTok = new StringTokenizer(myString, ","); myTok.hasMoreTokens();){
      myStream.write(Byte.parseByte(myTok.nextToken().trim()));
     }
     return myStream.toByteArray();

    }
    public static void main(String[] args){
     String myString = new byteToString().convertToString();

     toByteArray(myString);


    }
}

Thanks ahead!! :)

Answer 1

new byte[] {91,79,44,32,79,44,32,79,44,32,79,93} is actually [O, O, O, O] array of Ohs not zeroes!

Use new byte[] {91,48,44,32,48,44,32,48,44,32,48,93} instead.

Also want to note that you can use:

myString = myString.substring(1, myString.length() - 1);

instead of:

myString = myString.substring(0, myString.length()- 1).substring(1);.

It is more efficient.

Answer 2

public class AAA {

    public static final byte[] TEST_DATA = {91, 79, 44, 32, 79, 44, 32, 79, 44, 32, 79, 93};

    public String convertToString(byte[] array) {
        return Arrays.toString(array);
    }

    private static byte[] toByteArray(String myString) {
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();
        Pattern pattern = Pattern.compile("\\D*(\\d+)");
        Matcher matcher = pattern.matcher(myString);
        while (matcher.find()) {
            bOut.write((byte)Integer.parseInt(matcher.group(1)));
        }
        return bOut.toByteArray();
    }

    public static void main(String[] args) {
        String myString = new AAA().convertToString(TEST_DATA);
        byte[] bytes = toByteArray(myString);
        System.out.println("Test " + (Arrays.equals(bytes, TEST_DATA) ? "passed" : "failed"));
    }
}