Java Byte Array to String to Byte Array

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I'm trying to understand a byte[] to string, string representation of byte[] to byte[] conversion... I convert my byte[] to a string to send, I then expect my web service (written in python) to echo the data straight back to the client.

When I send the data from my Java application...

Arrays.toString(data.toByteArray())

Bytes to send.. 

[B@405217f8

Send (This is the result of Arrays.toString() which should be a string representation of my byte data, this data will be sent across the wire): 

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

On the python side, the python server returns a string to the caller (which I can see is the same as the string I sent to the server

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

The server should return this data to the client, where it can be verified.

The response my client receives (as a string) looks like

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

I can't seem to figure out how to get the received string back into a byte[]

Whatever I seem to try I end up getting a byte array which looks as follows...

[91, 45, 52, 55, 44, 32, 49, 44, 32, 49, 54, 44, 32, 56, 52, 44, 32, 50, 44, 32, 49, 48, 49, 44, 32, 49, 49, 48, 44, 32, 56, 51, 44, 32, 49, 49, 49, 44, 32, 49, 48, 57, 44, 32, 49, 48, 49, 44, 32, 51, 50, 44, 32, 55, 56, 44, 32, 55, 48, 44, 32, 54, 55, 44, 32, 51, 50, 44, 32, 54, 56, 44, 32, 57, 55, 44, 32, 49, 49, 54, 44, 32, 57, 55, 93]

or I can get a byte representation which is as follows:

B@2a80d889

Both of these are different from my sent data... I'm sure Im missing something truly simple....

Any help?!

byte java string
12 Answers

[JAVA 8]

import java.util.Base64;

String dummy= "dummy string";
byte[] byteArray = dummy.getBytes();

byte[] salt = new byte[]{ -47, 1, 16, ... }
String encoded = Base64.getEncoder().encodeToString(salt);
user_6496050

You can do the following to convert byte array to string and then convert that string to byte array:

// 1. convert byte array to string and then string to byte array

    // convert byte array to string
    byte[] by_original = {0, 1, -2, 3, -4, -5, 6};
    String str1 = Arrays.toString(by_original);
    System.out.println(str1); // output: [0, 1, -2, 3, -4, -5, 6]

    // convert string to byte array
    String newString = str1.substring(1, str1.length()-1);
    String[] stringArray = newString.split(", ");
    byte[] by_new = new byte[stringArray.length];
    for(int i=0; i<stringArray.length; i++) {
        by_new[i] = (byte) Integer.parseInt(stringArray[i]);
    }
    System.out.println(Arrays.toString(by_new)); // output: [0, 1, -2, 3, -4, -5, 6]

But to convert the string to byte array and then convert that byte array to string, below approach can be used:

// 2. convert string to byte array and then byte array to string

    // convert string to byte array
    String str2 = "[0, 1, -2, 3, -4, -5, 6]";
    byte[] byteStr2 = str2.getBytes(StandardCharsets.UTF_8);
    // Now byteStr2 is [91, 48, 44, 32, 49, 44, 32, 45, 50, 44, 32, 51, 44, 32, 45, 52, 44, 32, 45, 53, 44, 32, 54, 93]

    // convert byte array to string
    System.out.println(new String(byteStr2, StandardCharsets.UTF_8)); // output: [0, 1, -2, 3, -4, -5, 6]

I have also answered the same in the following question: https://stackoverflow.com/a/70486387/17364272

user_173642720
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