Ethereum: Base58-encode a String in Java

Base58 encoding is a widely used method for encoding large data sets into compact and printable characters. In this article, we will explore how to Base58-encode a string in Java using the [Java 8’s Base64 class](

Prerequisites

• Java 1.8 or later

• A string to be Base58-encoded

Code

import java.nio.charset.StandardCharsets;

import java.util.Base64;


public class Main {

    public static void main(String[] args) {

        String testString = "56379c7bcd6b41188854e74169f844e8676cf8b8";

        byte[] encodedBytes = encodeBase58(testString);

        System.out.println("Encoded bytes: " + Base64.getEncoder().encodeToString(encodedBytes));

    }


    public static byte[] encodeBase58(String input) {

        // Create a new Base64Encoder instance

        Base64.Encoder encoder = Base64.getEncoder();


        // Define the base 58 alphabet and padding scheme

        String alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";

        int paddingLength = 0;


        // Loop until input string is less than 1 byte

        while (input.length() >= 1) {

            // Append the next character to the encoded string

            int i = 0;

            while ((i < input.length()) && (input.charAt(i) <= alphabet.size())) {

                encoder.update(input, i);

                i++;

            }


            // Calculate padding length if necessary

            paddingLength = paddingLength + (input.length() - i);


            // Append the padding character to the encoded string

            String paddingChar = "=".repeat(paddingLength);

            encodedBytes[i] = paddingChar.getBytes();


            input = input.substring(i);

        }

        return encodedBytes;

    }

}

Explanation

• The encodeBase58 method takes a string as input and returns an array of bytes.

• We create a new Base64.Encoder instance using the java.nio.charset.StandardCharsets.UTF_8 parameter, which is the default encoding used by Java’s Base64 class.

• We define the base 58 alphabet (alphabet) and padding scheme (paddingLength).

• We loop until the input string is less than 1 byte in length. In each iteration, we append the next character from the input string to the encoded string using encoder.update(input, i).

• If necessary, we calculate padding length by subtracting the current index from the total length of the input string and append a repeating padding character (=) to the encoded string.

• Finally, we return the array of bytes.

Example Use Case

You can use this method in a Java program to encode strings for storage or transmission using Base58 encoding.

public class Example {

    public static void main(String[] args) {

        String testString = "Hello, World!";

        byte[] encodedBytes = encodeBase58(testString);

        System.out.println("Encoded bytes: " + Base64.getEncoder().encodeToString(encodedBytes));

    }

}

Note that this implementation does not support encoding large strings. If you need to handle long input strings, consider using a dedicated library or framework that supports efficient Base58 encoding and decoding, such as [OpenPGP]( or [Ethereum’s Web3.js](

PROTECT CRYPTOCURRENCY ASSETS CASHING