write java code for Terra Classic Crypto network

Here is an example Java code for implementing the Terra Classic Crypto network:

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class TerraClassicCryptoNetwork {

    public static void main(String[] args) {
        String message = "Hello, Terra Classic!";
        String privateKey = "YOUR_PRIVATE_KEY";
        
        try {
            // Generate SHA-256 hash of the message
            String hash = generateHash(message);
            System.out.println("Hash: " + hash);
            
            // Sign the hash with the private key
            String signature = signHash(hash, privateKey);
            System.out.println("Signature: " + signature);
            
            // Verify the signature
            boolean isValid = verifySignature(hash, signature, privateKey);
            System.out.println("Signature is valid: " + isValid);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }
    
    // Generate SHA-256 hash of the message
    public static String generateHash(String message) throws NoSuchAlgorithmException {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        byte[] hashBytes = digest.digest(message.getBytes());
        
        StringBuilder hexString = new StringBuilder();
        for (byte hashByte : hashBytes) {
            String hex = Integer.toHexString(0xff & hashByte);
            if (hex.length() == 1)
                hexString.append('0');
            hexString.append(hex);
        }
        
        return hexString.toString();
    }
    
    // Sign the hash with the private key
    public static String signHash(String hash, String privateKey) throws NoSuchAlgorithmException {
        // TODO: Implement your signing algorithm here
        return "SIGNATURE";
    }
    
    // Verify the signature
    public static boolean verifySignature(String hash, String signature, String publicKey) throws NoSuchAlgorithmException {
        // TODO: Implement your signature verification algorithm here
        return true; // Return true if the signature is valid, false otherwise
    }
}

Note that the signing and signature verification methods (signHash and verifySignature) are left as placeholders and need to be implemented according to the specific signing algorithm and public key infrastructure used in the Terra Classic Crypto network