P256K1XOnlyPubKey: add toString() method

Author: msgilligan

secp-api/src/main/java/org/bitcoinj/secp/api/P256K1XOnlyPubKey.java

@@ -16,6 +16,7 @@
 package org.bitcoinj.secp.api;
 
 import java.math.BigInteger;
+import java.util.HexFormat;
 
 /**
  *
@@ -55,6 +56,7 @@ static P256K1XOnlyPubKey of(BigInteger x) {
      * Default implementation. Currently used by all known implementations
      */
     class P256K1XOnlyPubKeyImpl implements P256K1XOnlyPubKey {
+        private static final HexFormat formatter = HexFormat.of();
         private final BigInteger x;
 
         public P256K1XOnlyPubKeyImpl(P256k1PubKey pubKey) {
@@ -78,5 +80,13 @@ public BigInteger getX() {
         public byte[] getSerialized() {
             return P256k1PubKey.integerTo32Bytes(x);
         }
+
+        /**
+         * @return A hex string representing the default binary serialization format
+         */
+        @Override
+        public String toString() {
+            return formatter.formatHex(getSerialized());
+        }
     }
 }

secp-examples-java/src/main/java/org/bitcoinj/secp/examples/Schnorr.java

@@ -65,7 +65,7 @@ public static void main(String[] args) {
 
             System.out.printf("Is the signature valid? %s\n", is_signature_valid);
             System.out.printf("Secret Key: %s\n", keyPair.getS().toString(16));
-            System.out.printf("Public Key (as ECPoint): %s\n", formatter.formatHex(xOnly2.getSerialized()));
+            System.out.printf("Public Key (as ECPoint): %s\n", xOnly2);
             System.out.printf("Signature: %s\n", formatter.formatHex(signature));
 
             /* It's best practice to try to clear secrets from memory after using them.

secp-examples-kotlin/src/main/java/org/bitcoinj/secp/kotlin/examples/Schnorr.kt

@@ -60,7 +60,7 @@ object Schnorr {
 
             System.out.printf("Is the signature valid? %s\n", is_signature_valid)
             System.out.printf("Secret Key: %s\n", keyPair.s.toString(16))
-            System.out.printf("Public Key (as ECPoint): %s\n", formatter.formatHex(xOnly2.serialized))
+            System.out.printf("Public Key (as ECPoint): %s\n", xOnly2)
             System.out.printf("Signature: %s\n", formatter.formatHex(signature))
 
             /* It's best practice to try to clear secrets from memory after using them.