redesign the challenge provider interface to be Java compatible

src/main/java/Challenge.java

@@ -0,0 +1,13 @@
+package lc;
+
+public class Challenge {
+  public final byte[] content;
+  public final String contentType;
+  public final String secret;
+
+  public Challenge(final byte[] content, final String contentType, final String secret) {
+    this.content = content;
+    this.contentType = contentType;
+    this.secret = secret;
+  }
+}

src/main/java/ChallengeProvider.java

@@ -0,0 +1,10 @@
+package lc;
+
+interface ChallengeProvider {
+  public String getId();
+  public Challenge returnChallenge();
+  public boolean checkAnswer(String secret, String answer);
+
+  //TODO: def configure(): Unit
+}
+

src/main/scala/lc/FilterChallenge.scala

@@ -6,9 +6,9 @@ import java.awt.image.BufferedImage
 import java.awt.Font
 import java.awt.Color
 
-class FilterChallenge extends ChallengeProvider{
+class FilterChallenge extends ChallengeProvider {
-  val id = "filter"
+  def getId = "filter"
-  def returnChallenge(): (Image, String) = {
+  def returnChallenge(): Challenge = {
     val filterTypes = List(new FilterType1, new FilterType2)
     val r = new scala.util.Random
     val alphabet = "abcdefghijklmnopqrstuvwxyz"
@@ -25,7 +25,7 @@ class FilterChallenge extends ChallengeProvider{
     var image = new Image(canvas, ImageMetadata.empty)
     val s = scala.util.Random.nextInt(2)
     image = filterTypes(s).applyFilter(image)
-    (image, secret)
+    new Challenge(image.bytes, "image/png", secret)
   }
   def checkAnswer(secret: String, answer: String): Boolean = {
     secret == answer

src/main/scala/lc/Main.scala

@@ -15,13 +15,6 @@ import org.json4s.jackson.Serialization.{read, write}
 import java.util.concurrent._
 import scala.Array
 
-trait ChallengeProvider {
-  val id: String
-  def returnChallenge(): (Image, String)
-  def checkAnswer(secret: String, answer: String): Boolean
-  //TODO: def configure(): Unit
-}
-
 class Captcha {
   val con: Connection = DriverManager.getConnection("jdbc:h2:./captcha", "sa", "")
   val stmt: Statement = con.createStatement()
@@ -47,13 +40,13 @@ class Captcha {
   	//TODO: eval params to choose a provider
   	val providerMap = "FilterChallenge"
   	val provider = filters(providerMap)
-    val (image, secret) = provider.returnChallenge()
+    val challenge = provider.returnChallenge()
-    val blob = new ByteArrayInputStream(image.bytes)
+    val blob = new ByteArrayInputStream(challenge.content)
     val token = scala.util.Random.nextInt(10000).toString
     val id = Id(token)
     insertPstmt.setString(1, token)
-    insertPstmt.setString(2, provider.id)
+    insertPstmt.setString(2, provider.getId)
-    insertPstmt.setString(3, secret)
+    insertPstmt.setString(3, challenge.secret)
     insertPstmt.setString(4, providerMap)
     insertPstmt.setBlob(5, blob)
     insertPstmt.executeUpdate()
@@ -64,13 +57,13 @@ class Captcha {
   	val providerMap = "FilterChallenge"
   	val provider = filters(providerMap)
   	def run(): Unit = {
-	    val (image, secret) = provider.returnChallenge()
+	    val challenge = provider.returnChallenge()
-	    val blob = new ByteArrayInputStream(image.bytes)
+	    val blob = new ByteArrayInputStream(challenge.content)
 	    val token = scala.util.Random.nextInt(10000).toString
 	    val id = Id(token)
 	    insertPstmt.setString(1, token)
-	    insertPstmt.setString(2, provider.id)
+	    insertPstmt.setString(2, provider.getId)
-	    insertPstmt.setString(3, secret)
+	    insertPstmt.setString(3, challenge.secret)
 	    insertPstmt.setString(4, providerMap)
 	    insertPstmt.setBlob(5, blob)
 	    insertPstmt.executeUpdate()