remove Util object

src/main/scala/com/fluency03/blockchain/api/package.scala

@@ -1,5 +1,6 @@
 package com.fluency03.blockchain
 
+import akka.http.scaladsl.model.{StatusCode, StatusCodes}
 import com.fluency03.blockchain.core.{Block, Peer, Transaction}
 
 package object api {
@@ -17,6 +18,4 @@ package object api {
   val PARENT_UP = "../"
 
 
-
-
 }

src/main/scala/com/fluency03/blockchain/api/routes/BlockRoutes.scala

@@ -21,13 +21,13 @@ trait BlockRoutes extends RoutesSupport {
   def blocksActor: ActorRef
 
   lazy val blockRoutes: Route =
-    path("blocks") {
+    path(BLOCKS) {
       get {
         val blocks: Future[Blocks] = (blocksActor ? GetBlocks).mapTo[Blocks]
         complete(blocks)
       }
     } ~
-    pathPrefix("block") {
+    pathPrefix(BLOCK) {
       pathEnd {
         post {
           entity(as[Block]) { block =>

src/main/scala/com/fluency03/blockchain/api/routes/BlockchainRoutes.scala

@@ -21,7 +21,7 @@ trait BlockchainRoutes extends RoutesSupport {
   def blockchainActor: ActorRef
 
   lazy val blockchainRoutes: Route =
-    pathPrefix("blockchain") {
+    pathPrefix(BLOCKCHAIN) {
       pathEnd {
         get {
           val blockchain: Future[Option[Blockchain]] = (blockchainActor ? GetBlockchain).mapTo[Option[Blockchain]]

src/main/scala/com/fluency03/blockchain/api/routes/GenericRoutes.scala

@@ -4,13 +4,11 @@ package api.routes
 import java.time.Instant
 
 import akka.event.Logging
-import akka.http.scaladsl.model.StatusCodes
 import akka.http.scaladsl.server.Directives._
 import akka.http.scaladsl.server.Route
 import akka.http.scaladsl.server.directives.MethodDirectives.post
 import akka.http.scaladsl.server.directives.RouteDirectives.complete
-import com.fluency03.blockchain.Util._
-import com.fluency03.blockchain.api.{FailureMsg, Input, SuccessMsg}
+import com.fluency03.blockchain.api.{Input, SuccessMsg}
 
 trait GenericRoutes extends RoutesSupport {
   lazy val log = Logging(system, classOf[GenericRoutes])

src/main/scala/com/fluency03/blockchain/api/routes/NetworkRoutes.scala

@@ -21,13 +21,13 @@ trait NetworkRoutes extends RoutesSupport {
   def networkActor: ActorRef
 
   lazy val networkRoutes: Route =
-    path("peers") {
+    path(PEERS) {
       get {
         val peers: Future[Set[String]] = (networkActor ? GetPeers).mapTo[Set[String]]
         complete(peers)
       }
     } ~
-    pathPrefix("peer") {
+    pathPrefix(PEER) {
       pathEnd {
         post {
           entity(as[PeerSimple]) { peer =>

src/main/scala/com/fluency03/blockchain/api/routes/TransactionRoutes.scala

@@ -21,13 +21,13 @@ trait TransactionRoutes extends RoutesSupport {
   def transActor: ActorRef
 
   lazy val transRoutes: Route =
-    path("transactions") {
+    path(TRANSACTIONS) {
       get {
         val transactions: Future[Transactions] = (transActor ? GetTransactions).mapTo[Transactions]
         complete(transactions)
       }
     } ~
-    pathPrefix("transaction") {
+    pathPrefix(TRANSACTION) {
       pathEnd {
         post {
           entity(as[Transaction]) { tx =>

src/main/scala/com/fluency03/blockchain/api/routes/package.scala

@@ -1,5 +1,7 @@
 package com.fluency03.blockchain.api
 
+import akka.http.scaladsl.model.{StatusCode, StatusCodes}
+
 package object routes {
 
   // generics
@@ -11,6 +13,47 @@ package object routes {
   val TO_EPOCH_TIME = "to-epoch-time"
   val TIME_FROM_EPOCH = "time-from-epoch"
 
+  // blockchain
+  val BLOCKCHAIN = "blockchain"
+
+  // block
+  val BLOCKS = "blocks"
+  val BLOCK = "block"
+
+  // network
+  val PEERS = "peers"
+  val PEER = "peer"
+
+  // transaction
+  val TRANSACTIONS = "transactions"
+  val TRANSACTION = "transaction"
+
+  /**
+   * Concatenate a seq of String segments into full API path
+   */
   def pathOf(seg: String*): String = SLASH + seg.mkString(SLASH)
 
+  /**
+   * Return either SuccessMsg (if fun successfully returned a String) or FailureMsg (if fun failed).
+   */
+  def failsafeMsg(fun: => String): Message =
+    try { SuccessMsg(fun) }
+    catch {
+      case e: Exception => FailureMsg(e.getMessage)
+    }
+
+  /**
+   * Return either SuccessMsg (if fun successfully returned a String) or FailureMsg (if fun failed).
+   */
+  def failsafeResp(fun: => String): (StatusCode, Message) =
+    try { (StatusCodes.OK, SuccessMsg(fun)) }
+    catch {
+      case e: Exception => (StatusCodes.InternalServerError, FailureMsg(e.getMessage))
+    }
+
+
+
+
+
+
 }

src/main/scala/com/fluency03/blockchain/core/Block.scala

@@ -1,7 +1,6 @@
 package com.fluency03.blockchain
 package core
 
-import com.fluency03.blockchain.Util.isWithValidDifficulty
 import com.fluency03.blockchain.core.BlockHeader.hashOfHeaderFields
 import com.fluency03.blockchain.core.Transaction.createCoinbaseTx
 import org.json4s.JsonAST.JObject

src/main/scala/com/fluency03/blockchain/core/BlockHeader.scala

@@ -2,7 +2,6 @@ package com.fluency03.blockchain
 package core
 
 import com.fluency03.blockchain.core.BlockHeader.hashOfBlockHeader
-import com.fluency03.blockchain.Util.sha256Of
 import org.json4s.native.JsonMethods.{compact, render}
 import org.json4s.{Extraction, JValue}
 

src/main/scala/com/fluency03/blockchain/core/Blockchain.scala

@@ -1,12 +1,9 @@
 package com.fluency03.blockchain
 package core
 
-import com.fluency03.blockchain.Util.getCurrentTimestamp
 import com.fluency03.blockchain.core.Blockchain._
 import com.fluency03.blockchain.core.Block.canBeChained
 
-import scala.collection.mutable
-
 /**
  * Blockchain with difficulty and the chain of Blocks.
  * @param difficulty Difficulty of a Blockchain

src/main/scala/com/fluency03/blockchain/core/Merkle.scala

@@ -1,8 +1,6 @@
 package com.fluency03.blockchain
 package core
 
-import com.fluency03.blockchain.Util.sha256Of
-
 object Merkle {
   def computeRoot(trans: Seq[Transaction]): String =
     computeRootOfHashes(trans.map(_.id))

src/main/scala/com/fluency03/blockchain/core/Transaction.scala

@@ -4,7 +4,6 @@ package core
 import java.security.KeyPair
 
 import com.fluency03.blockchain.Crypto
-import com.fluency03.blockchain.Util.sha256Of
 import com.fluency03.blockchain.core.Transaction.hashOfTransaction
 import org.bouncycastle.util.encoders.Hex
 import org.json4s.JsonAST.JObject

src/main/scala/com/fluency03/blockchain/package.scala

@@ -1,9 +1,9 @@
 package com.fluency03
 
 import java.nio.charset.Charset
+import java.security.MessageDigest
 import java.time.Instant
 
-import com.fluency03.blockchain.Util.{sha256HashOf, base64Of, binaryOfHex}
 import org.bouncycastle.util.encoders.{Base64, Hex}
 import org.json4s.{Formats, NoTypeHints}
 import org.json4s.native.Serialization
@@ -41,4 +41,61 @@ package object blockchain {
     def toBase64: String = base64Of(bytes)
   }
 
+
+  /**
+   * Generate SHA256 Hash from a input String.
+   * https://gist.github.com/navicore/6234040bbfce3aa58f866db314c07c15
+   */
+  def sha256HashOf(text: String) : String = String.format("%064x",
+    new java.math.BigInteger(1, digestOf(text)))
+
+  /**
+   * Generate digest from a input String.
+   * https://gist.github.com/navicore/6234040bbfce3aa58f866db314c07c15
+   */
+  def digestOf(text: String): Bytes =
+    MessageDigest.getInstance("SHA-256").digest(text.getBytes("UTF-8"))
+
+  /**
+   * Calculate the hash of concatenation a Seq of Strings.
+   */
+  def sha256Of(strings: String*): String = sha256HashOf(strings mkString "")
+
+  /**
+   * Return the current timestamp in Unix Epoch Time.
+   */
+  def getCurrentTimestamp: Long = Instant.now.getEpochSecond
+
+  /**
+   * Parse a time format string to its Epoch time in seconds.
+   */
+  def epochTimeOf(t: String): Long = Instant.parse(t).getEpochSecond
+
+  /**
+   * Get binary representation of a hash.
+   */
+  def binaryOfHex(hash: String): String = BigInt(hash, 16).toString(2)
+
+  /**
+   * Check whether the given hash is with valid difficulty.
+   */
+  def isWithValidDifficulty(hash: String, difficulty: Int): Boolean = hash startsWith ("0" * difficulty)
+
+  /**
+   * Encode a String to Base64.
+   */
+  def base64Of(text: String): String = Base64.toBase64String(text.getBytes("UTF-8"))
+
+  /**
+   * Encode an Array of Bytes String to Base64.
+   */
+  def base64Of(data: Bytes): String = Base64.toBase64String(data)
+
+  /**
+   * Decode a Base64 to String.
+   */
+  def fromBase64(base64: String): String = new String(Base64.decode(base64), "UTF-8")
+
+
+
 }

src/test/scala/com/fluency03/blockchain/UtilTest.scala

@@ -2,7 +2,6 @@ package com.fluency03.blockchain
 
 import java.time.format.DateTimeParseException
 
-import com.fluency03.blockchain.Util._
 import org.scalamock.scalatest.MockFactory
 import org.scalatest.{FlatSpec, Matchers}
 

src/test/scala/com/fluency03/blockchain/core/MerkleTest.scala

@@ -1,7 +1,6 @@
 package com.fluency03.blockchain
 package core
 
-import com.fluency03.blockchain.Util.sha256Of
 import com.fluency03.blockchain.core.Merkle._
 import com.fluency03.blockchain.core.Transaction.createCoinbaseTx
 import org.scalatest.{FlatSpec, Matchers}