Revert "Container-jersey2: Scala code replaced with Java"

11 files changed, 338 insertions, 394 deletions

diff --git a/container-jersey2/pom.xml b/container-jersey2/pom.xml
index eb94b20700f..26dfa762032 100644
--- a/container-jersey2/pom.xml
+++ b/container-jersey2/pom.xml
@@ -54,10 +54,34 @@
       <artifactId>asm</artifactId>
       <version>5.0.3</version>
     </dependency>
+    <dependency>
+      <groupId>org.scala-lang</groupId>
+      <artifactId>scala-library</artifactId>
+    </dependency>
   </dependencies>
   <build>
     <plugins>
       <plugin>
+        <groupId>net.alchim31.maven</groupId>
+        <artifactId>scala-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>compile</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <phase>compile</phase>
+          </execution>
+          <execution>
+            <id>test-compile</id>
+            <goals>
+              <goal>testCompile</goal>
+            </goals>
+            <phase>test-compile</phase>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
         <groupId>com.yahoo.vespa</groupId>
         <artifactId>bundle-plugin</artifactId>
         <extensions>true</extensions>
diff --git a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ComponentGraphProvider.java b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ComponentGraphProvider.java
deleted file mode 100644
index 7ff9646cb27..00000000000
--- a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ComponentGraphProvider.java
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.container.servlet.jersey;
-
-import com.yahoo.container.di.config.ResolveDependencyException;
-import com.yahoo.container.di.config.RestApiContext;
-import com.yahoo.container.jaxrs.annotation.Component;
-import org.glassfish.hk2.api.Injectee;
-import org.glassfish.hk2.api.InjectionResolver;
-import org.glassfish.hk2.api.ServiceHandle;
-
-import javax.inject.Singleton;
-
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.stream.Collectors;
-
-/**
- * Resolves jdisc container components for jersey 2 components.
- *
- * @author Tony Vaagenes
- * @author ollivir
- */
-@Singleton // jersey2 requirement: InjectionResolvers must be in the Singleton scope
-public class ComponentGraphProvider implements InjectionResolver<Component> {
-    private Collection<RestApiContext.Injectable> injectables;
-
-    public ComponentGraphProvider(Collection<RestApiContext.Injectable> injectables) {
-        this.injectables = injectables;
-    }
-
-    @Override
-    public Object resolve(Injectee injectee, ServiceHandle<?> root) {
-        Class<?> wantedClass;
-        Type type = injectee.getRequiredType();
-        if (type instanceof Class) {
-            wantedClass = (Class<?>) type;
-        } else {
-            throw new UnsupportedOperationException("Only classes are supported, got " + type);
-        }
-
-        List<RestApiContext.Injectable> componentsWithMatchingType = new ArrayList<>();
-        for (RestApiContext.Injectable injectable : injectables) {
-            if (wantedClass.isInstance(injectable.instance)) {
-                componentsWithMatchingType.add(injectable);
-            }
-        }
-
-        if (componentsWithMatchingType.size() == 1) {
-            return componentsWithMatchingType.get(0).instance;
-        } else {
-            String injectionDescription = "class '" + wantedClass + "' to inject into Jersey resource/provider '"
-                    + injectee.getInjecteeClass() + "')";
-            if (componentsWithMatchingType.size() > 1) {
-                String ids = componentsWithMatchingType.stream().map(c -> c.id.toString()).collect(Collectors.joining(","));
-                throw new ResolveDependencyException("Multiple components found of " + injectionDescription + ": " + ids);
-            } else {
-                throw new ResolveDependencyException("Could not find a component of " + injectionDescription + ".");
-            }
-        }
-    }
-
-    @Override
-    public boolean isMethodParameterIndicator() {
-        return true;
-    }
-
-    @Override
-    public boolean isConstructorParameterIndicator() {
-        return true;
-    }
-}
diff --git a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyApplication.java b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyApplication.java
deleted file mode 100644
index 4c4e43bc8d5..00000000000
--- a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyApplication.java
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.container.servlet.jersey;
-
-import javax.ws.rs.core.Application;
-
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Set;
-
-/**
- * @author Tony Vaagenes
- * @author ollivir
- */
-public class JerseyApplication extends Application {
-    private Set<Class<?>> classes;
-
-    public JerseyApplication(Collection<Class<?>> resourcesAndProviderClasses) {
-        this.classes = new HashSet<>(resourcesAndProviderClasses);
-    }
-
-    @Override
-    public Set<Class<?>> getClasses() {
-        return classes;
-    }
-}
diff --git a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyServletProvider.java b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyServletProvider.java
deleted file mode 100644
index ab094e77650..00000000000
--- a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/JerseyServletProvider.java
+++ /dev/null
@@ -1,118 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.container.servlet.jersey;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
-import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
-import com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider;
-import com.yahoo.container.di.componentgraph.Provider;
-import com.yahoo.container.di.config.RestApiContext;
-import com.yahoo.container.di.config.RestApiContext.BundleInfo;
-import com.yahoo.container.jaxrs.annotation.Component;
-import org.eclipse.jetty.servlet.ServletHolder;
-import org.glassfish.hk2.api.InjectionResolver;
-import org.glassfish.hk2.api.TypeLiteral;
-import org.glassfish.hk2.utilities.Binder;
-import org.glassfish.hk2.utilities.binding.AbstractBinder;
-import org.glassfish.jersey.media.multipart.MultiPartFeature;
-import org.glassfish.jersey.server.ResourceConfig;
-import org.glassfish.jersey.servlet.ServletContainer;
-import org.objectweb.asm.ClassReader;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Optional;
-
-import static com.yahoo.container.servlet.jersey.util.ResourceConfigUtil.registerComponent;
-
-/**
- * @author Tony Vaagenes
- * @author ollivir
- */
-public class JerseyServletProvider implements Provider<ServletHolder> {
-    private final ServletHolder jerseyServletHolder;
-
-    public JerseyServletProvider(RestApiContext restApiContext) {
-        this.jerseyServletHolder = new ServletHolder(new ServletContainer(resourceConfig(restApiContext)));
-    }
-
-    private ResourceConfig resourceConfig(RestApiContext restApiContext) {
-        final ResourceConfig resourceConfig = ResourceConfig
-                .forApplication(new JerseyApplication(resourcesAndProviders(restApiContext.getBundles())));
-
-        registerComponent(resourceConfig, componentInjectorBinder(restApiContext));
-        registerComponent(resourceConfig, jacksonDatatypeJdk8Provider());
-        resourceConfig.register(MultiPartFeature.class);
-
-        return resourceConfig;
-    }
-
-    private static Collection<Class<?>> resourcesAndProviders(Collection<BundleInfo> bundles) {
-        final List<Class<?>> ret = new ArrayList<>();
-
-        for (BundleInfo bundle : bundles) {
-            for (String classEntry : bundle.getClassEntries()) {
-                Optional<String> className = detectResourceOrProvider(bundle.classLoader, classEntry);
-                className.ifPresent(cname -> ret.add(loadClass(bundle.symbolicName, bundle.classLoader, cname)));
-            }
-        }
-        return ret;
-    }
-
-    private static Optional<String> detectResourceOrProvider(ClassLoader bundleClassLoader, String classEntry) {
-        try (InputStream inputStream = getResourceAsStream(bundleClassLoader, classEntry)) {
-            ResourceOrProviderClassVisitor visitor = ResourceOrProviderClassVisitor.visit(new ClassReader(inputStream));
-            return Optional.ofNullable(visitor.getClassName());
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    private static InputStream getResourceAsStream(ClassLoader bundleClassLoader, String classEntry) {
-        InputStream is = bundleClassLoader.getResourceAsStream(classEntry);
-        if (is == null) {
-            throw new RuntimeException("No entry " + classEntry + " in bundle " + bundleClassLoader);
-        } else {
-            return is;
-        }
-    }
-
-    private static Class<?> loadClass(String bundleSymbolicName, ClassLoader classLoader, String className) {
-        try {
-            return classLoader.loadClass(className);
-        } catch (Exception e) {
-            throw new RuntimeException("Failed loading class " + className + " from bundle " + bundleSymbolicName, e);
-        }
-    }
-
-    private static Binder componentInjectorBinder(RestApiContext restApiContext) {
-        final ComponentGraphProvider componentGraphProvider = new ComponentGraphProvider(restApiContext.getInjectableComponents());
-        final TypeLiteral<InjectionResolver<Component>> componentAnnotationType = new TypeLiteral<InjectionResolver<Component>>() {
-        };
-
-        return new AbstractBinder() {
-            @Override
-            public void configure() {
-                bind(componentGraphProvider).to(componentAnnotationType);
-            }
-        };
-    }
-
-    private static JacksonJaxbJsonProvider jacksonDatatypeJdk8Provider() {
-        JacksonJaxbJsonProvider provider = new JacksonJaxbJsonProvider();
-        provider.setMapper(new ObjectMapper().registerModule(new Jdk8Module()).registerModule(new JavaTimeModule()));
-        return provider;
-    }
-
-    @Override
-    public ServletHolder get() {
-        return jerseyServletHolder;
-    }
-
-    @Override
-    public void deconstruct() {
-    }
-}
diff --git a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java
deleted file mode 100644
index 9abf573c73a..00000000000
--- a/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.java
+++ /dev/null
@@ -1,103 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.container.servlet.jersey;
-
-import org.objectweb.asm.AnnotationVisitor;
-import org.objectweb.asm.ClassReader;
-import org.objectweb.asm.ClassVisitor;
-import org.objectweb.asm.Opcodes;
-import org.objectweb.asm.Type;
-
-import javax.ws.rs.Path;
-import javax.ws.rs.ext.Provider;
-
-import java.util.HashSet;
-import java.util.Optional;
-import java.util.Set;
-
-/**
- * @author Tony Vaagenes
- * @author ollivir
- */
-public class ResourceOrProviderClassVisitor extends ClassVisitor {
-    private String className = null;
-    private boolean isPublic = false;
-    private boolean isAbstract = false;
-
-    private boolean isInnerClass = false;
-    private boolean isStatic = false;
-
-    private boolean isAnnotated = false;
-
-    public ResourceOrProviderClassVisitor() {
-        super(Opcodes.ASM5);
-    }
-
-    public Optional<String> getJerseyClassName() {
-        if (isJerseyClass()) {
-            return Optional.of(getClassName());
-        } else {
-            return Optional.empty();
-        }
-    }
-
-    public boolean isJerseyClass() {
-        return isAnnotated && isPublic && !isAbstract && (!isInnerClass || isStatic);
-    }
-
-    public String getClassName() {
-        assert (className != null);
-        return org.objectweb.asm.Type.getObjectType(className).getClassName();
-    }
-
-    @Override
-    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
-        isPublic = isPublic(access);
-        className = name;
-        isAbstract = isAbstract(access);
-    }
-
-    @Override
-    public void visitInnerClass(String name, String outerName, String innerName, int access) {
-        assert (className != null);
-
-        if (name.equals(className)) {
-            isInnerClass = true;
-            isStatic = isStatic(access);
-        }
-    }
-
-    @Override
-    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
-        isAnnotated |= annotationClassDescriptors.contains(desc);
-        return null;
-    }
-
-    private static Set<String> annotationClassDescriptors = new HashSet<>();
-
-    static {
-        annotationClassDescriptors.add(Type.getDescriptor(Path.class));
-        annotationClassDescriptors.add(Type.getDescriptor(Provider.class));
-    }
-
-    private static boolean isPublic(int access) {
-        return isSet(Opcodes.ACC_PUBLIC, access);
-    }
-
-    private static boolean isStatic(int access) {
-        return isSet(Opcodes.ACC_STATIC, access);
-    }
-
-    private static boolean isAbstract(int access) {
-        return isSet(Opcodes.ACC_ABSTRACT, access);
-    }
-
-    private static boolean isSet(int bits, int access) {
-        return (access & bits) == bits;
-    }
-
-    public static ResourceOrProviderClassVisitor visit(ClassReader classReader) {
-        ResourceOrProviderClassVisitor visitor = new ResourceOrProviderClassVisitor();
-        classReader.accept(visitor, ClassReader.SKIP_DEBUG | ClassReader.SKIP_CODE | ClassReader.SKIP_FRAMES);
-        return visitor;
-    }
-}
diff --git a/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ComponentGraphProvider.scala b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ComponentGraphProvider.scala
new file mode 100644
index 00000000000..cabde3680a4
--- /dev/null
+++ b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ComponentGraphProvider.scala
@@ -0,0 +1,40 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey
+
+import javax.inject.Singleton
+
+import com.yahoo.container.di.config.{ResolveDependencyException, RestApiContext}
+import com.yahoo.container.jaxrs.annotation.Component
+import org.glassfish.hk2.api.{ServiceHandle, Injectee, InjectionResolver}
+
+/**
+ * Resolves jdisc container components for jersey 2 components.
+ * Similar to Gjoran's ComponentGraphProvider for jersey 1.
+ * @author tonytv
+ */
+@Singleton //jersey2 requirement: InjectionResolvers must be in the Singleton scope
+class ComponentGraphProvider(injectables: Traversable[RestApiContext.Injectable]) extends InjectionResolver[Component] {
+  override def resolve(injectee: Injectee, root: ServiceHandle[_]): AnyRef = {
+    val wantedClass = injectee.getRequiredType match {
+      case c: Class[_] => c
+      case unsupported => throw new UnsupportedOperationException("Only classes are supported, got " + unsupported)
+    }
+
+    val componentsWithMatchingType = injectables.filter{ injectable =>
+        wantedClass.isInstance(injectable.instance) }
+
+    val injectionDescription =
+      s"class '$wantedClass' to inject into Jersey resource/provider '${injectee.getInjecteeClass}')"
+
+    if (componentsWithMatchingType.size > 1)
+      throw new ResolveDependencyException(s"Multiple components found of $injectionDescription: " +
+        componentsWithMatchingType.map(_.id).mkString(","))
+
+    componentsWithMatchingType.headOption.map(_.instance).getOrElse {
+      throw new ResolveDependencyException(s"Could not find a component of $injectionDescription.")
+    }
+  }
+
+  override def isMethodParameterIndicator: Boolean = true
+  override def isConstructorParameterIndicator: Boolean = true
+}
diff --git a/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyApplication.scala b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyApplication.scala
new file mode 100644
index 00000000000..eea41003984
--- /dev/null
+++ b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyApplication.scala
@@ -0,0 +1,16 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey
+
+import javax.ws.rs.core.Application
+
+import scala.collection.JavaConverters._
+
+/**
+ * @author tonytv
+ */
+class JerseyApplication(resourcesAndProviderClasses: Set[Class[_]]) extends Application {
+  private val classes: java.util.Set[Class[_]] = resourcesAndProviderClasses.asJava
+
+  override def getClasses = classes
+  override def getSingletons = super.getSingletons
+}
diff --git a/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyServletProvider.scala b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyServletProvider.scala
new file mode 100644
index 00000000000..f0eff54dc16
--- /dev/null
+++ b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/JerseyServletProvider.scala
@@ -0,0 +1,109 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey
+
+import java.io.{IOException, InputStream}
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
+import com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider
+import com.yahoo.container.di.componentgraph.Provider
+import com.yahoo.container.di.config.RestApiContext
+import com.yahoo.container.di.config.RestApiContext.BundleInfo
+import com.yahoo.container.jaxrs.annotation.Component
+import com.yahoo.container.servlet.jersey.util.ResourceConfigUtil.registerComponent
+import org.eclipse.jetty.servlet.ServletHolder
+import org.glassfish.hk2.api.{InjectionResolver, TypeLiteral}
+import org.glassfish.hk2.utilities.Binder
+import org.glassfish.hk2.utilities.binding.AbstractBinder
+import org.glassfish.jersey.media.multipart.MultiPartFeature
+import org.glassfish.jersey.server.ResourceConfig
+import org.glassfish.jersey.servlet.ServletContainer
+import org.objectweb.asm.ClassReader
+
+import scala.collection.JavaConverters._
+import scala.util.control.Exception
+
+
+/**
+ * @author tonytv
+ */
+class JerseyServletProvider(restApiContext: RestApiContext) extends Provider[ServletHolder] {
+  private val jerseyServletHolder = new ServletHolder(new ServletContainer(resourceConfig(restApiContext)))
+
+  private def resourceConfig(restApiContext: RestApiContext) = {
+    val resourceConfig = ResourceConfig.forApplication(
+      new JerseyApplication(resourcesAndProviders(restApiContext.getBundles.asScala)))
+
+    registerComponent(resourceConfig, componentInjectorBinder(restApiContext))
+    registerComponent(resourceConfig, jacksonDatatypeJdk8Provider)
+    resourceConfig.register(classOf[MultiPartFeature])
+
+    resourceConfig
+  }
+
+  def resourcesAndProviders(bundles: Traversable[BundleInfo]) =
+    (for {
+      bundle <- bundles.view
+      classEntry <- bundle.getClassEntries.asScala
+      className <- detectResourceOrProvider(bundle.classLoader, classEntry)
+    } yield loadClass(bundle.symbolicName, bundle.classLoader, className)).toSet
+
+
+  def detectResourceOrProvider(bundleClassLoader: ClassLoader, classEntry: String): Option[String] = {
+    using(getResourceAsStream(bundleClassLoader, classEntry)) { inputStream =>
+      val visitor = ResourceOrProviderClassVisitor.visit(new ClassReader(inputStream))
+      visitor.getJerseyClassName
+    }
+  }
+
+  private def getResourceAsStream(bundleClassLoader: ClassLoader, classEntry: String) = {
+    bundleClassLoader.getResourceAsStream(classEntry) match {
+      case null => throw new RuntimeException(s"No entry $classEntry in bundle $bundleClassLoader")
+      case stream => stream
+    }
+
+  }
+
+  def using[T <: InputStream, R](stream: T)(f: T => R): R = {
+    try {
+      f(stream)
+    } finally {
+      Exception.ignoring(classOf[IOException]) {
+        stream.close()
+      }
+    }
+  }
+
+  def loadClass(bundleSymbolicName: String, classLoader: ClassLoader, className: String) = {
+    try {
+      classLoader.loadClass(className)
+    } catch {
+      case e: Exception => throw new RuntimeException(s"Failed loading class $className from bundle $bundleSymbolicName", e)
+    }
+  }
+
+  def componentInjectorBinder(restApiContext: RestApiContext): Binder = {
+    val componentGraphProvider = new ComponentGraphProvider(restApiContext.getInjectableComponents.asScala)
+    val componentAnnotationType = new TypeLiteral[InjectionResolver[Component]] {}
+
+    new AbstractBinder {
+      override def configure() {
+        bind(componentGraphProvider).to(componentAnnotationType)
+      }
+    }
+  }
+
+  def jacksonDatatypeJdk8Provider: JacksonJaxbJsonProvider = {
+    val provider = new JacksonJaxbJsonProvider()
+    provider.setMapper(
+      new ObjectMapper()
+        .registerModule(new Jdk8Module)
+        .registerModule(new JavaTimeModule))
+    provider
+  }
+
+  override def get() = jerseyServletHolder
+  override def deconstruct() {}
+}
+
diff --git a/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.scala b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.scala
new file mode 100644
index 00000000000..c015f11360e
--- /dev/null
+++ b/container-jersey2/src/main/scala/com/yahoo/container/servlet/jersey/ResourceOrProviderClassVisitor.scala
@@ -0,0 +1,74 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey
+
+import javax.ws.rs.Path
+import javax.ws.rs.ext.Provider
+
+import org.objectweb.asm.{ClassVisitor, Opcodes, Type, AnnotationVisitor, ClassReader}
+
+
+/**
+ * @author tonytv
+ */
+class ResourceOrProviderClassVisitor private () extends ClassVisitor(Opcodes.ASM5) {
+  private var className: String = null
+  private var isPublic: Boolean = false
+  private var isAbstract = false
+
+  private var isInnerClass: Boolean = false
+  private var isStatic: Boolean = false
+
+  private var isAnnotated: Boolean = false
+
+  def getJerseyClassName: Option[String] = {
+    if (isJerseyClass) Some(getClassName)
+    else None
+  }
+
+  def isJerseyClass: Boolean = {
+    isAnnotated && isPublic && !isAbstract &&
+      (!isInnerClass || isStatic)
+  }
+
+  def getClassName = {
+    assert (className != null)
+    Type.getObjectType(className).getClassName
+  }
+
+  override def visit(version: Int, access: Int, name: String, signature: String, superName: String, interfaces: Array[String]) {
+    isPublic = ResourceOrProviderClassVisitor.isPublic(access)
+    className = name
+    isAbstract =  ResourceOrProviderClassVisitor.isAbstract(access)
+  }
+
+  override def visitInnerClass(name: String, outerName: String, innerName: String, access: Int) {
+    assert (className != null)
+
+    if (name == className) {
+      isInnerClass = true
+      isStatic = ResourceOrProviderClassVisitor.isStatic(access)
+    }
+  }
+
+  override def visitAnnotation(desc: String, visible: Boolean): AnnotationVisitor = {
+    isAnnotated |= ResourceOrProviderClassVisitor.annotationClassDescriptors(desc)
+    null
+  }
+}
+
+
+object ResourceOrProviderClassVisitor {
+  val annotationClassDescriptors = Set(classOf[Path], classOf[Provider]) map Type.getDescriptor
+
+  def isPublic = isSet(Opcodes.ACC_PUBLIC) _
+  def isStatic = isSet(Opcodes.ACC_STATIC) _
+  def isAbstract = isSet(Opcodes.ACC_ABSTRACT) _
+
+  private def isSet(bits: Int)(access: Int): Boolean = (access & bits) == bits
+
+  def visit(classReader: ClassReader): ResourceOrProviderClassVisitor = {
+    val visitor = new ResourceOrProviderClassVisitor
+    classReader.accept(visitor, ClassReader.SKIP_DEBUG | ClassReader.SKIP_CODE | ClassReader.SKIP_FRAMES)
+    visitor
+  }
+}
diff --git a/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.java b/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.java
deleted file mode 100644
index a4f186c3c78..00000000000
--- a/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.java
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.container.servlet.jersey.classvisitor;
-
-import com.yahoo.container.servlet.jersey.ResourceOrProviderClassVisitor;
-import org.junit.Assert;
-import org.junit.Test;
-import org.objectweb.asm.ClassReader;
-
-import java.io.IOException;
-
-import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
-
-public class ResourceOrProviderClassVisitorTest {
-    @Test
-    public void resource_is_detected() throws IOException {
-        assert_is_accepted(Resource.class);
-    }
-
-    @Test
-    public void provider_is_detected() throws IOException {
-        assert_is_accepted(Provider.class);
-    }
-
-    @Test
-    public void inner_class_is_ignored() throws IOException {
-        assert_is_ignored(InnerClass.Inner.class);
-    }
-
-    @Test
-    public void nested_public_class_is_detected() throws IOException {
-        assert_is_accepted(NestedClass.Nested.class);
-    }
-
-    @Test
-    public void nested_non_public_class_is_ignored() throws IOException {
-        assert_is_ignored(NonPublicNestedClass.Nested.class);
-    }
-
-    @Test
-    public void resource_with_multiple_annotations_is_detected() throws IOException {
-        assert_is_accepted(ResourceWithMultipleAnnotations.class);
-    }
-
-    @Test
-    public void interface_is_ignored() throws IOException {
-        assert_is_ignored(InterfaceResource.class);
-    }
-
-    @Test
-    public void abstract_class_is_ignored() throws IOException {
-        assert_is_ignored(AbstractResource.class);
-    }
-
-    @Test
-    public void className_is_equal_to_getName() throws IOException {
-        assertThat(analyzeClass(Resource.class).getClassName(), is(Resource.class.getName()));
-    }
-
-    private static void assert_is_accepted(Class<?> clazz) throws IOException {
-        Assert.assertTrue(className(clazz) + " was not accepted", analyzeClass(clazz).isJerseyClass());
-    }
-
-    private static void assert_is_ignored(Class<?> clazz) throws IOException {
-        Assert.assertFalse(className(clazz) + " was not ignored", analyzeClass(clazz).isJerseyClass());
-    }
-
-    private static ResourceOrProviderClassVisitor analyzeClass(Class<?> clazz) throws IOException {
-        return ResourceOrProviderClassVisitor.visit(new ClassReader(className(clazz)));
-    }
-
-    private static String className(Class<?> clazz) {
-        return clazz.getName();
-    }
-}
diff --git a/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.scala b/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.scala
new file mode 100644
index 00000000000..f20c5e02e62
--- /dev/null
+++ b/container-jersey2/src/test/java/com/yahoo/container/servlet/jersey/classvisitor/ResourceOrProviderClassVisitorTest.scala
@@ -0,0 +1,75 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.servlet.jersey.classvisitor
+
+import com.yahoo.container.servlet.jersey.{ResourceOrProviderClassVisitor, classvisitor}
+import org.junit.{Assert, Test}
+import org.objectweb.asm.ClassReader
+
+import Assert.assertThat
+import org.hamcrest.CoreMatchers.is
+
+import scala.reflect.ClassTag
+
+class ResourceOrProviderClassVisitorTest {
+  @Test
+  def resource_is_detected() {
+    assert_is_accepted[classvisitor.Resource]
+  }
+
+  @Test
+  def provider_is_detected() {
+    assert_is_accepted[classvisitor.Provider]
+  }
+
+  @Test
+  def inner_class_is_ignored() {
+    assert_is_ignored[classvisitor.InnerClass#Inner]
+  }
+
+  @Test
+  def nested_public_class_is_detected() {
+    assert_is_accepted[classvisitor.NestedClass.Nested]
+  }
+
+  @Test
+  def nested_non_public_class_is_ignored() {
+    assert_is_ignored[classvisitor.NonPublicNestedClass.Nested]
+  }
+
+  @Test
+  def resource_with_multiple_annotations_is_detected() {
+    assert_is_accepted[classvisitor.ResourceWithMultipleAnnotations]
+  }
+
+  def interface_is_ignored() {
+    assert_is_ignored[classvisitor.InterfaceResource]
+  }
+
+  @Test
+  def abstract_class_is_ignored() {
+    assert_is_ignored[classvisitor.AbstractResource]
+  }
+
+  @Test
+  def className_is_equal_to_getName() {
+    assertThat(analyzeClass[classvisitor.Resource].getClassName, is(classOf[classvisitor.Resource].getName))
+  }
+
+  def assert_is_accepted[T: ClassTag] {
+    Assert.assertTrue(className[T] + " was not accepted",
+      analyzeClass[T].isJerseyClass)
+  }
+
+  def assert_is_ignored[T: ClassTag] {
+    Assert.assertFalse(className[T] + " was not ignored",
+      analyzeClass[T].isJerseyClass)
+  }
+
+  def analyzeClass[T: ClassTag] = {
+    ResourceOrProviderClassVisitor.visit(new ClassReader(className[T]))
+  }
+
+  def className[T: ClassTag] = implicitly[ClassTag[T]].runtimeClass.getName
+}
+
+