1 files changed, 73 insertions, 0 deletions
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
new file mode 100644
index 00000000000..7ff9646cb27
--- /dev/null
+++ b/container-jersey2/src/main/java/com/yahoo/container/servlet/jersey/ComponentGraphProvider.java
@@ -0,0 +1,73 @@
+// 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;
+    }
+}