删除多余的工具类代码

Author: wangweiX

src/main/java/one/wangwei/blockchain/block/Block.java

@@ -8,7 +8,7 @@
 import one.wangwei.blockchain.pow.ProofOfWork;
 import one.wangwei.blockchain.transaction.MerkleTree;
 import one.wangwei.blockchain.transaction.Transaction;
-import org.apache.commons.codec.binary.Hex;
+import one.wangwei.blockchain.util.ByteUtils;
 
 import java.time.Instant;
 
@@ -24,8 +24,6 @@
 @ToString
 public class Block {
 
-    private static final String ZERO_HASH = Hex.encodeHexString(new byte[32]);
-
     /**
      * 区块hash值
      */
@@ -47,15 +45,14 @@ public class Block {
      */
     private long nonce;
 
-
     /**
      * <p> 创建创世区块 </p>
      *
      * @param coinbase
      * @return
      */
     public static Block newGenesisBlock(Transaction coinbase) {
-        return Block.newBlock(ZERO_HASH, new Transaction[]{coinbase});
+        return Block.newBlock(ByteUtils.ZERO_HASH, new Transaction[]{coinbase});
     }
 
     /**

src/main/java/one/wangwei/blockchain/util/Base58Check.java

@@ -5,28 +5,34 @@
  * https://www.nayuki.io/page/bitcoin-cryptography-library
  * https://github.com/nayuki/Bitcoin-Cryptography-Library
  */
-
 package one.wangwei.blockchain.util;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.util.Arrays;
 
-
 /**
- * Converts between an array of bytes and a Base58Check string. Not instantiable.
+ * Base58 转化工具
  */
 public final class Base58Check {
 
-    /*---- Static functions ----*/
-
-    // Adds the checksum and converts to Base58Check. Note that the caller needs to prepend the version byte(s).
+    /**
+     * 添加校验码并转化为 Base58 字符串
+     *
+     * @param data
+     * @return
+     */
     public static String bytesToBase58(byte[] data) {
         return rawBytesToBase58(addCheckHash(data));
     }
 
-    // Directly converts to Base58Check without adding a checksum.
+    /**
+     * 转化为 Base58 字符串
+     *
+     * @param data
+     * @return
+     */
     public static String rawBytesToBase58(byte[] data) {
         // Convert to base-58 string
         StringBuilder sb = new StringBuilder();
@@ -38,16 +44,22 @@ public static String rawBytesToBase58(byte[] data) {
         }
 
         // Add '1' characters for leading 0-value bytes
-        for (int i = 0; i < data.length && data[i] == 0; i++)
+        for (int i = 0; i < data.length && data[i] == 0; i++) {
             sb.append(ALPHABET.charAt(0));
+        }
         return sb.reverse().toString();
     }
 
 
-    // Returns a new byte array by concatenating the given array with its checksum.
+    /**
+     * 添加校验码并返回待有校验码的原生数据
+     *
+     * @param data
+     * @return
+     */
     static byte[] addCheckHash(byte[] data) {
         try {
-            byte[] hash = Arrays.copyOf(Sha256.getDoubleHash(data).toBytes(), 4);
+            byte[] hash = Arrays.copyOf(BtcAddressUtils.doubleHash(data), 4);
             ByteArrayOutputStream buf = new ByteArrayOutputStream();
             buf.write(data);
             buf.write(hash);
@@ -58,41 +70,53 @@ static byte[] addCheckHash(byte[] data) {
     }
 
 
-    // Converts the given Base58Check string to a byte array, verifies the checksum, and removes the checksum to return the payload.
-    // The caller is responsible for handling the version byte(s).
+    /**
+     * 将 Base58Check 字符串转化为 byte 数组，并校验其校验码
+     * 返回的byte数组带有版本号，但不带有校验码
+     *
+     * @param s
+     * @return
+     */
     public static byte[] base58ToBytes(String s) {
         byte[] concat = base58ToRawBytes(s);
         byte[] data = Arrays.copyOf(concat, concat.length - 4);
         byte[] hash = Arrays.copyOfRange(concat, concat.length - 4, concat.length);
-        byte[] rehash = Arrays.copyOf(Sha256.getDoubleHash(data).toBytes(), 4);
-        if (!Arrays.equals(rehash, hash))
+        byte[] rehash = Arrays.copyOf(BtcAddressUtils.doubleHash(data), 4);
+        if (!Arrays.equals(rehash, hash)) {
             throw new IllegalArgumentException("Checksum mismatch");
+        }
         return data;
     }
 
 
-    // Converts the given Base58Check string to a byte array, without checking or removing the trailing 4-byte checksum.
+    /**
+     * 将 Base58Check 字符串反转为 byte 数组
+     *
+     * @param s
+     * @return
+     */
     static byte[] base58ToRawBytes(String s) {
         // Parse base-58 string
         BigInteger num = BigInteger.ZERO;
         for (int i = 0; i < s.length(); i++) {
             num = num.multiply(ALPHABET_SIZE);
             int digit = ALPHABET.indexOf(s.charAt(i));
-            if (digit == -1)
+            if (digit == -1) {
                 throw new IllegalArgumentException("Invalid character for Base58Check");
+            }
             num = num.add(BigInteger.valueOf(digit));
         }
-
         // Strip possible leading zero due to mandatory sign bit
         byte[] b = num.toByteArray();
-        if (b[0] == 0)
+        if (b[0] == 0) {
             b = Arrays.copyOfRange(b, 1, b.length);
-
+        }
         try {
             // Convert leading '1' characters to leading 0-value bytes
             ByteArrayOutputStream buf = new ByteArrayOutputStream();
-            for (int i = 0; i < s.length() && s.charAt(i) == ALPHABET.charAt(0); i++)
+            for (int i = 0; i < s.length() && s.charAt(i) == ALPHABET.charAt(0); i++) {
                 buf.write(0);
+            }
             buf.write(b);
             return buf.toByteArray();
         } catch (IOException e) {

src/main/java/one/wangwei/blockchain/util/BtcAddressUtils.java

@@ -11,6 +11,16 @@
  * @date 2018/03/21
  */
 public class BtcAddressUtils {
+    
+    /**
+     * 双重Hash
+     *
+     * @param data
+     * @return
+     */
+    public static byte[] doubleHash(byte[] data) {
+        return DigestUtils.sha256(DigestUtils.sha256(data));
+    }
 
     /**
      * 计算公钥的 RIPEMD160 Hash值
@@ -28,16 +38,14 @@ public static byte[] ripeMD160Hash(byte[] pubKey) {
         return output;
     }
 
-
     /**
      * 生成公钥的校验码
      *
      * @param payload
      * @return
      */
     public static byte[] checksum(byte[] payload) {
-        byte[] firstSHA = DigestUtils.sha256(payload);
-        byte[] secondSHA = DigestUtils.sha256(firstSHA);
-        return Arrays.copyOfRange(secondSHA, 0, 4);
+        return Arrays.copyOfRange(doubleHash(payload), 0, 4);
     }
+
 }

src/main/java/one/wangwei/blockchain/util/ByteUtils.java

@@ -1,5 +1,6 @@
 package one.wangwei.blockchain.util;
 
+import org.apache.commons.codec.binary.Hex;
 import org.apache.commons.lang3.ArrayUtils;
 
 import java.nio.ByteBuffer;
@@ -14,6 +15,12 @@
  */
 public class ByteUtils {
 
+    public static final byte[] EMPTY_ARRAY = new byte[0];
+
+    public static final byte[] EMPTY_BYTES = new byte[32];
+
+    public static final String ZERO_HASH = Hex.encodeHexString(EMPTY_BYTES);
+
     /**
      * 将多个字节数组合并成一个字节数组
      *
@@ -22,7 +29,7 @@ public class ByteUtils {
      */
     public static byte[] merge(byte[]... bytes) {
         Stream<Byte> stream = Stream.of();
-        for (byte[] b : bytes) {
+        for (byte[] b: bytes) {
             stream = Stream.concat(stream, Arrays.stream(ArrayUtils.toObject(b)));
         }
         return ArrayUtils.toPrimitive(stream.toArray(Byte[]::new));