Linter and Formatter support (#58)

* Add scala linter and formatter

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Add java formatter

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Add linter support

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Increase maxColumn limit

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Reformat and lint

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Minor reformatting

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Add scala formatter on compile option

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

* Enable scala linter for CI

Signed-off-by: Rahul Rudragoudar <rr83019@gmail.com>

.github/workflows/scala.yml

@@ -19,3 +19,5 @@ jobs:
         java-version: 1.8
     - name: Run tests
       run: sbt test
+    - name: Run linter
+      run: sbt "scalafixAll --check"

.scalafix.conf

@@ -0,0 +1,8 @@
+rules=[
+    ExplicitResultTypes,
+    RemoveUnused,
+    DisableSyntax,
+    LeakingImplicitClassVal,
+    NoValInForComprehension,
+    ProcedureSyntax
+]

.scalafmt.conf

@@ -0,0 +1,2 @@
+version=2.5.2 
+maxColumn = 120

.travis.yml

@@ -4,3 +4,4 @@ scala:
         - 2.13.2
 script:
         - sbt ++$TRAVIS_SCALA_VERSION compile
+        - sbt "scalafixAll --check"

build.sbt

@@ -1,21 +1,27 @@
-lazy val root = (project in file(".")).
+lazy val root = (project in file(".")).settings(
-  settings(
+  inThisBuild(
-    inThisBuild(List(
+    List(
       organization := "com.example",
       scalaVersion := "2.13.3",
-      version      := "0.1.0-SNAPSHOT")),
+      version := "0.1.0-SNAPSHOT",
+      semanticdbEnabled := true,
+      semanticdbVersion := scalafixSemanticdb.revision,
+      scalafixScalaBinaryVersion := "2.13"
+    )
+  ),
   name := "LibreCaptcha",
-
   libraryDependencies += "com.sksamuel.scrimage" % "scrimage-core" % "4.0.5",
-
   libraryDependencies += "com.sksamuel.scrimage" % "scrimage-filters" % "4.0.5",
-
   libraryDependencies += "org.json4s" % "json4s-jackson_2.13" % "3.6.9"
-
 )
 
 unmanagedResourceDirectories in Compile += { baseDirectory.value / "lib" }
+scalacOptions ++= List(
+  "-Yrangepos",
+  "-Ywarn-unused"
+)
 javacOptions += "-g:none"
+scalafmtOnCompile := true
 compileOrder := CompileOrder.JavaThenScala
 
 fork in run := true

project/plugins.sbt

@@ -0,0 +1,3 @@
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.25")
+addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.0")
+addSbtPlugin("com.lightbend.sbt" % "sbt-java-formatter" % "0.6.0")

src/main/java/lc/captchas/FontFunCaptcha.java

@@ -18,18 +18,19 @@ public class FontFunCaptcha implements ChallengeProvider{
 
   private String getFontName(String path, String level) {
     File file = new File(path + level + "/");
-        FilenameFilter txtFileFilter = new FilenameFilter() {
+    FilenameFilter txtFileFilter =
+        new FilenameFilter() {
           @Override
-            public boolean accept(File dir, String name)
+          public boolean accept(File dir, String name) {
-            {
+            if (name.endsWith(".ttf")) return true;
-                if(name.endsWith(".ttf"))
+            else return false;
-                    return true;
-                else
-                    return false;
           }
         };
     File[] files = file.listFiles(txtFileFilter);
-        return path+level.toLowerCase()+"/"+files[HelperFunctions.randomNumber(0,files.length-1)].getName();
+    return path
+        + level.toLowerCase()
+        + "/"
+        + files[HelperFunctions.randomNumber(0, files.length - 1)].getName();
   }
 
   private Font loadCustomFont(String level, String path) {
@@ -54,7 +55,8 @@ public class FontFunCaptcha implements ChallengeProvider{
       FontMetrics fontMetrics = graphics2D.getFontMetrics();
       HelperFunctions.setRenderingHints(graphics2D);
       graphics2D.setColor(Color.decode(colors[HelperFunctions.randomNumber(0, 3)]));
-            graphics2D.drawString(String.valueOf(captchaText.charAt(i)), (i * 48), fontMetrics.getAscent());
+      graphics2D.drawString(
+          String.valueOf(captchaText.charAt(i)), (i * 48), fontMetrics.getAscent());
     }
     graphics2D.dispose();
     ByteArrayOutputStream baos = new ByteArrayOutputStream();

src/main/java/lc/captchas/GifCaptcha.java

@@ -21,7 +21,8 @@ public class GifCaptcha implements ChallengeProvider{
     Font font = new Font("Bradley Hand", Font.ROMAN_BASELINE, 48);
     Graphics2D graphics2D = img.createGraphics();
     graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
-        graphics2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+    graphics2D.setRenderingHint(
+        RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
     graphics2D.setFont(font);
     graphics2D.setColor(new Color((int) (Math.random() * 0x1000000)));
     graphics2D.drawString(text, 45, 45);

src/main/java/lc/captchas/ShadowTextCaptcha.java

@@ -29,7 +29,8 @@ public class ShadowTextCaptcha implements ChallengeProvider{
     Font font = new Font("Arial", Font.ROMAN_BASELINE, 48);
     Graphics2D graphics2D = img.createGraphics();
     graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
-        graphics2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+    graphics2D.setRenderingHint(
+        RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
 
     TextLayout textLayout = new TextLayout(text, font, graphics2D.getFontRenderContext());
     HelperFunctions.setRenderingHints(graphics2D);
@@ -43,8 +44,7 @@ public class ShadowTextCaptcha implements ChallengeProvider{
       1f / 9f, 1f / 9f, 1f / 9f,
       1f / 9f, 1f / 9f, 1f / 9f
     };
-        ConvolveOp op =  new ConvolveOp(new Kernel(3, 3, kernel),
+    ConvolveOp op = new ConvolveOp(new Kernel(3, 3, kernel), ConvolveOp.EDGE_NO_OP, null);
-                ConvolveOp.EDGE_NO_OP, null);
     BufferedImage img2 = op.filter(img, null);
     Graphics2D g2d = img2.createGraphics();
     HelperFunctions.setRenderingHints(g2d);

src/main/java/lc/captchas/interfaces/ChallengeProvider.java

@@ -2,7 +2,9 @@ package lc.captchas.interfaces;
 
 public interface ChallengeProvider {
   public String getId();
+
   public Challenge returnChallenge();
+
   public boolean checkAnswer(String secret, String answer);
 
   // TODO: def configure(): Unit

src/main/java/lc/misc/GifSequenceWriter.java

@@ -2,6 +2,7 @@
 // It was available under CC By 3.0
 
 package lc.misc;
+
 import javax.imageio.*;
 import javax.imageio.metadata.*;
 import javax.imageio.stream.*;
@@ -22,51 +23,39 @@ public class GifSequenceWriter {
    * @param timeBetweenFramesMS the time between frames in miliseconds
    * @param loopContinuously wether the gif should loop repeatedly
    * @throws IIOException if no gif ImageWriters are found
-     *
    * @author Elliot Kroo (elliot[at]kroo[dot]net)
    */
   public GifSequenceWriter(
       ImageOutputStream outputStream,
       int imageType,
       int timeBetweenFramesMS,
-            boolean loopContinuously) throws IIOException, IOException {
+      boolean loopContinuously)
+      throws IIOException, IOException {
     // my method to create a writer
     gifWriter = getWriter();
     imageWriteParam = gifWriter.getDefaultWriteParam();
     ImageTypeSpecifier imageTypeSpecifier =
         ImageTypeSpecifier.createFromBufferedImageType(imageType);
 
-        imageMetaData =
+    imageMetaData = gifWriter.getDefaultImageMetadata(imageTypeSpecifier, imageWriteParam);
-                gifWriter.getDefaultImageMetadata(imageTypeSpecifier,
-                        imageWriteParam);
 
     String metaFormatName = imageMetaData.getNativeMetadataFormatName();
 
-        IIOMetadataNode root = (IIOMetadataNode)
+    IIOMetadataNode root = (IIOMetadataNode) imageMetaData.getAsTree(metaFormatName);
-                imageMetaData.getAsTree(metaFormatName);
 
-        IIOMetadataNode graphicsControlExtensionNode = getNode(
+    IIOMetadataNode graphicsControlExtensionNode = getNode(root, "GraphicControlExtension");
-                root,
-                "GraphicControlExtension");
 
     graphicsControlExtensionNode.setAttribute("disposalMethod", "none");
     graphicsControlExtensionNode.setAttribute("userInputFlag", "FALSE");
+    graphicsControlExtensionNode.setAttribute("transparentColorFlag", "FALSE");
     graphicsControlExtensionNode.setAttribute(
-                "transparentColorFlag",
+        "delayTime", Integer.toString(timeBetweenFramesMS / 10));
-                "FALSE");
+    graphicsControlExtensionNode.setAttribute("transparentColorIndex", "0");
-        graphicsControlExtensionNode.setAttribute(
-                "delayTime",
-                Integer.toString(timeBetweenFramesMS / 10));
-        graphicsControlExtensionNode.setAttribute(
-                "transparentColorIndex",
-                "0");
 
     IIOMetadataNode commentsNode = getNode(root, "CommentExtensions");
     commentsNode.setAttribute("CommentExtension", "Created by MAH");
 
-        IIOMetadataNode appEntensionsNode = getNode(
+    IIOMetadataNode appEntensionsNode = getNode(root, "ApplicationExtensions");
-                root,
-                "ApplicationExtensions");
 
     IIOMetadataNode child = new IIOMetadataNode("ApplicationExtension");
 
@@ -75,8 +64,7 @@ public class GifSequenceWriter {
 
     int loop = loopContinuously ? 0 : 1;
 
-        child.setUserObject(new byte[]{ 0x1, (byte) (loop & 0xFF), (byte)
+    child.setUserObject(new byte[] {0x1, (byte) (loop & 0xFF), (byte) ((loop >> 8) & 0xFF)});
-                ((loop >> 8) & 0xFF)});
     appEntensionsNode.appendChild(child);
 
     imageMetaData.setFromTree(metaFormatName, root);
@@ -87,25 +75,19 @@ public class GifSequenceWriter {
   }
 
   public void writeToSequence(RenderedImage img) throws IOException {
-        gifWriter.writeToSequence(
+    gifWriter.writeToSequence(new IIOImage(img, null, imageMetaData), imageWriteParam);
-                new IIOImage(
-                        img,
-                        null,
-                        imageMetaData),
-                imageWriteParam);
   }
 
   /**
-     * Close this GifSequenceWriter object. This does not close the underlying
+   * Close this GifSequenceWriter object. This does not close the underlying stream, just finishes
-     * stream, just finishes off the GIF.
+   * off the GIF.
    */
   public void close() throws IOException {
     gifWriter.endWriteSequence();
   }
 
   /**
-     * Returns the first available GIF ImageWriter using
+   * Returns the first available GIF ImageWriter using ImageIO.getImageWritersBySuffix("gif").
-     * ImageIO.getImageWritersBySuffix("gif").
    *
    * @return a GIF ImageWriter object
    * @throws IIOException if no GIF image writers are returned
@@ -120,21 +102,17 @@ public class GifSequenceWriter {
   }
 
   /**
-     * Returns an existing child node, or creates and returns a new child node (if
+   * Returns an existing child node, or creates and returns a new child node (if the requested node
-     * the requested node does not exist).
+   * does not exist).
    *
    * @param rootNode the <tt>IIOMetadataNode</tt> to search for the child node.
    * @param nodeName the name of the child node.
-     *
    * @return the child node, if found or a new node created with the given name.
    */
-    private static IIOMetadataNode getNode(
+  private static IIOMetadataNode getNode(IIOMetadataNode rootNode, String nodeName) {
-            IIOMetadataNode rootNode,
-            String nodeName) {
     int nNodes = rootNode.getLength();
     for (int i = 0; i < nNodes; i++) {
-            if (rootNode.item(i).getNodeName().compareToIgnoreCase(nodeName)
+      if (rootNode.item(i).getNodeName().compareToIgnoreCase(nodeName) == 0) {
-                    == 0) {
         return ((IIOMetadataNode) rootNode.item(i));
       }
     }

src/main/java/lc/misc/HelperFunctions.java

@@ -5,10 +5,10 @@ import java.awt.*;
 public class HelperFunctions {
 
   public static void setRenderingHints(Graphics2D g2d) {
-        g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
+    g2d.setRenderingHint(
-                RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+        RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
-        g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS,
+    g2d.setRenderingHint(
-                RenderingHints.VALUE_FRACTIONALMETRICS_ON);
+        RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
   }
 
   public static String randomString(int n) {

src/main/scala/lc/Main.scala

@@ -1,16 +1,11 @@
 package lc
 
-import org.json4s.DefaultFormats
-import org.json4s.jackson.JsonMethods._
-import scala.io.Source.fromFile
-import lc.database.Statements
 import lc.core.{Captcha, CaptchaProviders}
 import lc.server.Server
 import lc.background.BackgroundTask
 
-
 object LCFramework {
-  def main(args: scala.Array[String]) {
+  def main(args: scala.Array[String]): Unit = {
     val captcha = new Captcha()
     val server = new Server(8888, captcha)
     val backgroudTask = new BackgroundTask(captcha, 10)
@@ -20,9 +15,10 @@ object LCFramework{
 }
 
 object MakeSamples {
-  def main(args: scala.Array[String]) {
+  def main(args: scala.Array[String]): Unit = {
     val samples = CaptchaProviders.generateChallengeSamples()
-    samples.foreach {case (key, sample) =>
+    samples.foreach {
+      case (key, sample) =>
         val extensionMap = Map("image/png" -> "png", "image/gif" -> "gif")
         println(key + ": " + sample)
 

src/main/scala/lc/background/taskThread.scala

@@ -5,7 +5,6 @@ import java.util.concurrent.{ScheduledThreadPoolExecutor, TimeUnit}
 import lc.core.Captcha
 import lc.core.{Parameters, Size}
 
-
 class BackgroundTask(captcha: Captcha, throttle: Int) {
 
   private val task = new Runnable {
@@ -32,7 +31,7 @@ class BackgroundTask(captcha: Captcha, throttle: Int) {
 
   def beginThread(delay: Int): Unit = {
     val ex = new ScheduledThreadPoolExecutor(1)
-    val thread = ex.scheduleWithFixedDelay(task, 1, delay, TimeUnit.SECONDS)
+    ex.scheduleWithFixedDelay(task, 1, delay, TimeUnit.SECONDS)
   }
 
 }

src/main/scala/lc/captchas/FilterChallenge.scala

@@ -8,7 +8,6 @@ import java.awt.Color
 import lc.captchas.interfaces.ChallengeProvider
 import lc.captchas.interfaces.Challenge
 
-
 class FilterChallenge extends ChallengeProvider {
   def getId = "FilterChallenge"
   def returnChallenge(): Challenge = {
@@ -62,4 +61,3 @@ class FilterType2 extends FilterType {
     image
   }
 }
-

src/main/scala/lc/captchas/LabelCaptcha.scala

@@ -4,17 +4,17 @@ import java.io.File
 import java.io.ByteArrayOutputStream
 import javax.imageio.ImageIO
 import scala.collection.mutable.Map
-import java.nio.file.{Files,Path,StandardCopyOption}
+import java.nio.file.{Files, StandardCopyOption}
 import java.awt.image.BufferedImage
-import java.awt.{Graphics2D,Color}
+import java.awt.Color
 import lc.captchas.interfaces.ChallengeProvider
 import lc.captchas.interfaces.Challenge
 
 class LabelCaptcha extends ChallengeProvider {
   private var knownFiles = new File("known").list.toList
   private var unknownFiles = new File("unknown").list.toList
-  private var unknownAnswers = Map[String, Map[String, Int]]()
+  private val unknownAnswers = Map[String, Map[String, Int]]()
-  private var total = Map[String, Int]()
+  private val total = Map[String, Int]()
 
   for (file <- unknownFiles) {
     unknownAnswers += file -> Map[String, Int]()
@@ -23,15 +23,15 @@ class LabelCaptcha extends ChallengeProvider {
 
   def getId = "LabelCaptcha"
 
-  def returnChallenge(): Challenge = synchronized {
+  def returnChallenge(): Challenge =
+    synchronized {
       val r = scala.util.Random.nextInt(knownFiles.length)
       val s = scala.util.Random.nextInt(unknownFiles.length)
       val knownImageFile = knownFiles(r)
       val unknownImageFile = unknownFiles(s)
-    val ip = new ImagePair(knownImageFile, unknownImageFile)
 
-    var knownImage = ImageIO.read(new File("known/"+knownImageFile))
+      val knownImage = ImageIO.read(new File("known/" + knownImageFile))
-    var unknownImage = ImageIO.read(new File("unknown/"+unknownImageFile))
+      val unknownImage = ImageIO.read(new File("unknown/" + unknownImageFile))
       val mergedImage = merge(knownImage, unknownImage)
 
       val token = encrypt(knownImageFile + "," + unknownImageFile)
@@ -55,7 +55,8 @@ class LabelCaptcha extends ChallengeProvider {
     finalImage
   }
 
-  def checkAnswer(token: String, input: String): Boolean = synchronized {
+  def checkAnswer(token: String, input: String): Boolean =
+    synchronized {
       val parts = decrypt(token).split(",")
       val knownImage = parts(0)
       val unknownImage = parts(1)
@@ -73,7 +74,11 @@ class LabelCaptcha extends ChallengeProvider {
         if (total(unknownFile) >= 3) {
           if ((unknownAnswers(unknownFile)(userAnswer(1)) / total(unknownFile)) >= 0.9) {
             unknownAnswers -= unknownFile
-          Files.move(new File("unknown/"+unknownFile).toPath, new File("known/"+userAnswer(1)+".png").toPath, StandardCopyOption.REPLACE_EXISTING)
+            Files.move(
+              new File("unknown/" + unknownFile).toPath,
+              new File("known/" + userAnswer(1) + ".png").toPath,
+              StandardCopyOption.REPLACE_EXISTING
+            )
             knownFiles = new File("known").list.toList
             unknownFiles = new File("unknown").list.toList
           }

src/main/scala/lc/captchas/RainDropsCaptcha.scala

@@ -5,9 +5,7 @@ import java.awt.RenderingHints
 import java.awt.Font
 import java.awt.font.TextAttribute
 import java.awt.Color
-import java.io.ByteArrayOutputStream
+import java.io.ByteArrayOutputStream;
-import javax.imageio.ImageIO
-import javax.imageio.stream.ImageOutputStream;
 import javax.imageio.stream.MemoryCacheImageOutputStream;
 import lc.captchas.interfaces.ChallengeProvider
 import lc.captchas.interfaces.Challenge
@@ -19,7 +17,7 @@ class Drop {
   var yOffset = 0
   var color = 0
   var colorChange = 10
-  def mkColor = {
+  def mkColor: Color = {
     new Color(color, color, math.min(200, color + 100))
   }
 }
@@ -60,8 +58,11 @@ class RainDropsCP extends ChallengeProvider {
         d.colorChange *= -1
       }
     }
-    val drops = dropsOrig ++ extendDrops(dropsOrig, 1, xOffset) ++ extendDrops(dropsOrig, 2, xOffset) ++ extendDrops(dropsOrig, 3, xOffset)
+    val drops = dropsOrig ++ extendDrops(dropsOrig, 1, xOffset) ++ extendDrops(dropsOrig, 2, xOffset) ++ extendDrops(
-
+      dropsOrig,
+      3,
+      xOffset
+    )
 
     val baseFont = new Font(Font.MONOSPACED, Font.BOLD, 80)
     val attributes = new java.util.HashMap[TextAttribute, Object]()
@@ -72,7 +73,7 @@ class RainDropsCP extends ChallengeProvider {
     val baos = new ByteArrayOutputStream();
     val ios = new MemoryCacheImageOutputStream(baos);
     val writer = new GifSequenceWriter(ios, imgType, 60, true);
-    for(i <- 0 until 60){
+    for (_ <- 0 until 60) {
       // val yOffset = 5+r.nextInt(5)
       val canvas = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB)
       val g = canvas.createGraphics()

src/main/scala/lc/core/captcha.scala

@@ -1,6 +1,5 @@
 package lc.core
 
-import org.json4s.JsonAST.JValue
 import java.sql.{Blob, ResultSet}
 import java.util.UUID
 import java.io.ByteArrayInputStream
@@ -23,7 +22,8 @@ class Captcha {
         }
       }
       image
-    } catch { case e: Exception =>
+    } catch {
+      case e: Exception =>
         println(e)
         image
     }
@@ -64,7 +64,8 @@ class Captcha {
       updateAttemptedPstmt.setString(1, uuid)
       updateAttemptedPstmt.executeUpdate()
       Id(uuid)
-    } catch {case e: Exception => 
+    } catch {
+      case e: Exception =>
         println(e)
         Id(getUUID(-1))
     }

src/main/scala/lc/core/captchaProviders.scala

@@ -2,6 +2,7 @@ package lc.core
 
 import lc.captchas._
 import lc.captchas.interfaces.ChallengeProvider
+import lc.captchas.interfaces.Challenge
 
 object CaptchaProviders {
   private val providers = Map(
@@ -9,12 +10,13 @@ object CaptchaProviders {
     //"FontFunCaptcha" -> new FontFunCaptcha,
     "GifCaptcha" -> new GifCaptcha,
     "ShadowTextCaptcha" -> new ShadowTextCaptcha,
-    "RainDropsCaptcha" -> new RainDropsCP,
+    "RainDropsCaptcha" -> new RainDropsCP
     //"LabelCaptcha" -> new LabelCaptcha
   )
 
-  def generateChallengeSamples() = {
+  def generateChallengeSamples(): Map[String, Challenge] = {
-    providers.map {case (key, provider) =>
+    providers.map {
+      case (key, provider) =>
         (key, provider.returnChallenge())
     }
   }
@@ -22,7 +24,8 @@ object CaptchaProviders {
   private val seed = System.currentTimeMillis.toString.substring(2, 6).toInt
   private val random = new scala.util.Random(seed)
 
-  private def getNextRandomInt(max: Int) = random.synchronized {
+  private def getNextRandomInt(max: Int) =
+    random.synchronized {
       random.nextInt(max)
     }
 

src/main/scala/lc/database/statements.scala

@@ -2,30 +2,108 @@ package lc.database
 
 import lc.database.DBConn
 import java.sql.Statement
+import java.sql.PreparedStatement
 
 class Statements(dbConn: DBConn) {
 
   private val stmt = dbConn.getStatement()
 
-  stmt.execute("CREATE TABLE IF NOT EXISTS challenge(token int auto_increment, id varchar, secret varchar, provider varchar, contentType varchar, image blob, attempted int default 0, PRIMARY KEY(token))")
+  stmt.execute(
-  stmt.execute("CREATE TABLE IF NOT EXISTS mapId(uuid varchar, token int, lastServed timestamp, PRIMARY KEY(uuid), FOREIGN KEY(token) REFERENCES challenge(token) ON DELETE CASCADE)")
+    "CREATE TABLE IF NOT EXISTS challenge" +
+      "(token int auto_increment, " +
+      "id varchar, " +
+      "secret varchar, " +
+      "provider varchar, " +
+      "contentType varchar, " +
+      "image blob, " +
+      "attempted int default 0, " +
+      "PRIMARY KEY(token))"
+  )
+  stmt.execute(
+    "CREATE TABLE IF NOT EXISTS mapId" +
+      "(uuid varchar, " +
+      "token int, " +
+      "lastServed timestamp, " +
+      "PRIMARY KEY(uuid), " +
+      "FOREIGN KEY(token) " +
+      "REFERENCES challenge(token) " +
+      "ON DELETE CASCADE)"
+  )
 
-  val insertPstmt = dbConn.con.prepareStatement("INSERT INTO challenge(id, secret, provider, contentType, image) VALUES (?, ?, ?, ?, ?)", Statement.RETURN_GENERATED_KEYS )
+  val insertPstmt: PreparedStatement = dbConn.con.prepareStatement(
-  val mapPstmt = dbConn.con.prepareStatement("INSERT INTO mapId(uuid, token, lastServed) VALUES (?, ?, CURRENT_TIMESTAMP)")
+    "INSERT INTO " +
-  val selectPstmt = dbConn.con.prepareStatement("SELECT c.secret, c.provider FROM challenge c, mapId m WHERE m.token=c.token AND DATEDIFF(MINUTE, CURRENT_TIMESTAMP, DATEADD(MINUTE, 1, m.lastServed)) > 0 AND m.uuid = ?")
+      "challenge(id, secret, provider, contentType, image) " +
-  val imagePstmt = dbConn.con.prepareStatement("SELECT image FROM challenge c, mapId m WHERE c.token=m.token AND m.uuid = ?")
+      "VALUES (?, ?, ?, ?, ?)",
-  val updateAttemptedPstmt = dbConn.con.prepareStatement("UPDATE challenge SET attempted = attempted+1 WHERE token = (SELECT m.token FROM mapId m, challenge c WHERE m.token=c.token AND m.uuid = ?)")
+    Statement.RETURN_GENERATED_KEYS
-  val tokenPstmt = dbConn.con.prepareStatement("SELECT token FROM challenge WHERE attempted < 10 ORDER BY RAND() LIMIT 1")
+  )
-  val deleteAnswerPstmt = dbConn.con.prepareStatement("DELETE FROM mapId WHERE uuid = ?")
+
-  val challengeGCPstmt = dbConn.con.prepareStatement("DELETE FROM challenge WHERE attempted >= 10 AND token NOT IN (SELECT token FROM mapId)")
+  val mapPstmt: PreparedStatement =
-  val mapIdGCPstmt = dbConn.con.prepareStatement("DELETE FROM mapId WHERE DATEDIFF(MINUTE, CURRENT_TIMESTAMP, DATEADD(MINUTE, 1, lastServed)) < 0")
+    dbConn.con.prepareStatement(
+      "INSERT INTO " +
+        "mapId(uuid, token, lastServed) " +
+        "VALUES (?, ?, CURRENT_TIMESTAMP)"
+    )
+
+  val selectPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT c.secret, c.provider " +
+      "FROM challenge c, mapId m " +
+      "WHERE m.token=c.token AND " +
+      "DATEDIFF(MINUTE, CURRENT_TIMESTAMP, DATEADD(MINUTE, 1, m.lastServed)) > 0 AND " +
+      "m.uuid = ?"
+  )
+
+  val imagePstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT image " +
+      "FROM challenge c, mapId m " +
+      "WHERE c.token=m.token AND " +
+      "m.uuid = ?"
+  )
+
+  val updateAttemptedPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "UPDATE challenge " +
+      "SET attempted = attempted+1 " +
+      "WHERE token = (SELECT m.token " +
+      "FROM mapId m, challenge c " +
+      "WHERE m.token=c.token AND " +
+      "m.uuid = ?)"
+  )
+
+  val tokenPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT token " +
+      "FROM challenge " +
+      "WHERE attempted < 10 " +
+      "ORDER BY RAND() LIMIT 1"
+  )
+
+  val deleteAnswerPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "DELETE FROM mapId WHERE uuid = ?"
+  )
+
+  val challengeGCPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "DELETE FROM challenge " +
+      "WHERE attempted >= 10 AND " +
+      "token NOT IN (SELECT token FROM mapId)"
+  )
+
+  val mapIdGCPstmt: PreparedStatement = dbConn.con.prepareStatement(
+    "DELETE FROM mapId WHERE DATEDIFF(MINUTE, CURRENT_TIMESTAMP, DATEADD(MINUTE, 1, lastServed)) < 0"
+  )
+
+  val getCountChallengeTable: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT COUNT(*) AS total FROM challenge"
+  )
+
+  val getChallengeTable: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT * FROM challenge"
+  )
+
+  val getMapIdTable: PreparedStatement = dbConn.con.prepareStatement(
+    "SELECT * FROM mapId"
+  )
 
-  val getCountChallengeTable = dbConn.con.prepareStatement("SELECT COUNT(*) AS total FROM challenge")
-  val getChallengeTable = dbConn.con.prepareStatement("SELECT * FROM challenge")
-  val getMapIdTable = dbConn.con.prepareStatement("SELECT * FROM mapId")
 }
 
 object Statements {
   private val dbConn: DBConn = new DBConn()
-  val tlStmts = ThreadLocal.withInitial(() => new Statements(dbConn))
+  val tlStmts: ThreadLocal[Statements] = ThreadLocal.withInitial(() => new Statements(dbConn))
 }

src/main/scala/lc/server/Server.scala

@@ -7,14 +7,15 @@ import lc.core.Captcha
 import lc.core.{Parameters, Id, Answer}
 import lc.server.HTTPServer
 
-
 class Server(port: Int, captcha: Captcha) {
   val server = new HTTPServer(port)
-	val host = server.getVirtualHost(null)
+  val host: HTTPServer.VirtualHost = server.getVirtualHost(null)
 
-	implicit val formats = DefaultFormats
+  implicit val formats: DefaultFormats.type = DefaultFormats
 
-	host.addContext("/v1/captcha",(req, resp) => {
+  host.addContext(
+    "/v1/captcha",
+    (req, resp) => {
       val body = req.getJson()
       val json = parse(body)
       val param = json.extract[Parameters]
@@ -22,18 +23,26 @@ class Server(port: Int, captcha: Captcha){
       resp.getHeaders().add("Content-Type", "application/json")
       resp.send(200, write(id))
       0
-    },"POST")
+    },
+    "POST"
+  )
 
-    host.addContext("/v1/media",(req, resp) => {
+  host.addContext(
+    "/v1/media",
+    (req, resp) => {
       val params = req.getParams()
       val id = Id(params.get("id"))
       val image = captcha.getCaptcha(id)
       resp.getHeaders().add("Content-Type", "image/png")
       resp.send(200, image)
       0
-    },"GET")
+    },
+    "GET"
+  )
 
-    host.addContext("/v1/answer",(req, resp) => {
+  host.addContext(
+    "/v1/answer",
+    (req, resp) => {
       val body = req.getJson()
       val json = parse(body)
       val answer = json.extract[Answer]
@@ -41,8 +50,9 @@ class Server(port: Int, captcha: Captcha){
       resp.getHeaders().add("Content-Type", "application/json")
       resp.send(200, write(result))
       0
-    },"POST")
+    },
-
+    "POST"
+  )
 
   def start(): Unit = {
     println("Starting server on port:" + port)