Extract base class for http handlers to avoid code duplication

3 files changed, 75 insertions, 37 deletions

diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/HttpHandlerBase.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/HttpHandlerBase.java
new file mode 100644
index 00000000000..d3643bd8e61
--- /dev/null
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/HttpHandlerBase.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.http;
+
+import ai.vespa.metricsproxy.core.MetricsConsumers;
+import ai.vespa.metricsproxy.core.MetricsManager;
+import ai.vespa.metricsproxy.service.VespaServices;
+import com.yahoo.container.jdisc.HttpRequest;
+import com.yahoo.container.jdisc.HttpResponse;
+import com.yahoo.container.jdisc.ThreadedHttpRequestHandler;
+import com.yahoo.restapi.Path;
+
+import java.net.URI;
+import java.util.Optional;
+import java.util.concurrent.Executor;
+
+import static com.yahoo.jdisc.Response.Status.METHOD_NOT_ALLOWED;
+import static com.yahoo.jdisc.Response.Status.NOT_FOUND;
+import static com.yahoo.jdisc.http.HttpRequest.Method.GET;
+
+/**
+ * @author gjoranv
+ */
+public abstract class HttpHandlerBase extends ThreadedHttpRequestHandler {
+
+    protected final ValuesFetcher valuesFetcher;
+
+    protected HttpHandlerBase(Executor executor,
+                              MetricsManager metricsManager,
+                              VespaServices vespaServices,
+                              MetricsConsumers metricsConsumers) {
+        super(executor);
+        valuesFetcher = new ValuesFetcher(metricsManager, vespaServices, metricsConsumers);
+    }
+
+    protected abstract Optional<HttpResponse> doHandle(URI requestUri, Path apiPath, String consumer);
+
+    @Override
+    public final HttpResponse handle(HttpRequest request) {
+        if (request.getMethod() != GET) return new JsonResponse(METHOD_NOT_ALLOWED, "Only GET is supported");
+
+        Path path = new Path(request.getUri());
+
+        return doHandle(request.getUri(), path, getConsumer(request))
+                .orElse(new ErrorResponse(NOT_FOUND, "No content at given path"));
+    }
+
+    private String getConsumer(HttpRequest request) {
+        return request.getProperty("consumer");
+    }
+
+}
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/MetricsHandler.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/MetricsHandler.java
index 0d641b6cca4..87034c77524 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/MetricsHandler.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/MetricsHandler.java
@@ -10,58 +10,47 @@ import ai.vespa.metricsproxy.metric.model.MetricsPacket;
 import ai.vespa.metricsproxy.metric.model.json.JsonRenderingException;
 import ai.vespa.metricsproxy.service.VespaServices;
 import com.google.inject.Inject;
-import com.yahoo.container.jdisc.HttpRequest;
 import com.yahoo.container.jdisc.HttpResponse;
-import com.yahoo.container.jdisc.ThreadedHttpRequestHandler;
 import com.yahoo.restapi.Path;
 
+import java.net.URI;
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.Executor;
 
 import static ai.vespa.metricsproxy.http.RestApiUtil.resourceListResponse;
 import static ai.vespa.metricsproxy.metric.model.json.GenericJsonUtil.toGenericJsonModel;
 import static com.yahoo.jdisc.Response.Status.INTERNAL_SERVER_ERROR;
-import static com.yahoo.jdisc.Response.Status.METHOD_NOT_ALLOWED;
-import static com.yahoo.jdisc.Response.Status.NOT_FOUND;
 import static com.yahoo.jdisc.Response.Status.OK;
-import static com.yahoo.jdisc.http.HttpRequest.Method.GET;
 
 /**
  * Http handler for the metrics/v1 rest api.
  *
  * @author gjoranv
  */
-public class MetricsHandler extends ThreadedHttpRequestHandler {
+public class MetricsHandler extends HttpHandlerBase {
 
     public static final String V1_PATH = "/metrics/v1";
     static final String VALUES_PATH = V1_PATH + "/values";
 
-    private final ValuesFetcher valuesFetcher;
-
     @Inject
     public MetricsHandler(Executor executor,
                           MetricsManager metricsManager,
                           VespaServices vespaServices,
                           MetricsConsumers metricsConsumers) {
-        super(executor);
-        valuesFetcher = new ValuesFetcher(metricsManager, vespaServices, metricsConsumers);
+        super(executor, metricsManager, vespaServices, metricsConsumers);
     }
 
     @Override
-    public HttpResponse handle(HttpRequest request) {
-        if (request.getMethod() != GET) return new JsonResponse(METHOD_NOT_ALLOWED, "Only GET is supported");
-
-        Path path = new Path(request.getUri());
-
-        if (path.matches(V1_PATH)) return resourceListResponse(request.getUri(), List.of(VALUES_PATH));
-        if (path.matches(VALUES_PATH)) return valuesResponse(request);
-
-        return new ErrorResponse(NOT_FOUND, "No content at given path");
+    public Optional<HttpResponse> doHandle(URI requestUri, Path apiPath, String consumer) {
+        if (apiPath.matches(V1_PATH)) return Optional.of(resourceListResponse(requestUri, List.of(VALUES_PATH)));
+        if (apiPath.matches(VALUES_PATH)) return Optional.of(valuesResponse(consumer));
+        return Optional.empty();
     }
 
-    private JsonResponse valuesResponse(HttpRequest request) {
+    private JsonResponse valuesResponse(String consumer) {
         try {
-            List<MetricsPacket> metrics =  valuesFetcher.fetch(request.getProperty("consumer"));
+            List<MetricsPacket> metrics =  valuesFetcher.fetch(consumer);
             return new JsonResponse(OK, toGenericJsonModel(metrics).serialize());
         } catch (JsonRenderingException e) {
             return new ErrorResponse(INTERNAL_SERVER_ERROR, e.getMessage());
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java
index f2009280128..d2aa6a290bd 100644
--- a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java
+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/http/prometheus/PrometheusHandler.java
@@ -7,6 +7,7 @@ package ai.vespa.metricsproxy.http.prometheus;
 import ai.vespa.metricsproxy.core.MetricsConsumers;
 import ai.vespa.metricsproxy.core.MetricsManager;
 import ai.vespa.metricsproxy.http.ErrorResponse;
+import ai.vespa.metricsproxy.http.HttpHandlerBase;
 import ai.vespa.metricsproxy.http.JsonResponse;
 import ai.vespa.metricsproxy.http.TextResponse;
 import ai.vespa.metricsproxy.http.ValuesFetcher;
@@ -19,7 +20,9 @@ import com.yahoo.container.jdisc.HttpResponse;
 import com.yahoo.container.jdisc.ThreadedHttpRequestHandler;
 import com.yahoo.restapi.Path;
 
+import java.net.URI;
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.Executor;
 
 import static ai.vespa.metricsproxy.http.RestApiUtil.resourceListResponse;
@@ -33,37 +36,29 @@ import static com.yahoo.jdisc.http.HttpRequest.Method.GET;
 /**
  * @author gjoranv
  */
-public class PrometheusHandler extends ThreadedHttpRequestHandler {
+public class PrometheusHandler extends HttpHandlerBase {
 
     public static final String V1_PATH = "/prometheus/v1";
     static final String VALUES_PATH = V1_PATH + "/values";
 
-    private final ValuesFetcher valuesFetcher;
-
     @Inject
     public PrometheusHandler(Executor executor,
                              MetricsManager metricsManager,
                              VespaServices vespaServices,
                              MetricsConsumers metricsConsumers) {
-        super(executor);
-        valuesFetcher = new ValuesFetcher(metricsManager, vespaServices, metricsConsumers);
+        super(executor, metricsManager, vespaServices, metricsConsumers);
     }
 
     @Override
-    public HttpResponse handle(HttpRequest request) {
-        if (request.getMethod() != GET) return new JsonResponse(METHOD_NOT_ALLOWED, "Only GET is supported");
-
-        Path path = new Path(request.getUri());
-
-        if (path.matches(V1_PATH)) return resourceListResponse(request.getUri(), List.of(VALUES_PATH));
-        if (path.matches(VALUES_PATH)) return valuesResponse(request);
-
-        return new ErrorResponse(NOT_FOUND, "No content at given path");
+    public Optional<HttpResponse> doHandle(URI requestUri, Path apiPath, String consumer) {
+        if (apiPath.matches(V1_PATH)) return Optional.of(resourceListResponse(requestUri, List.of(VALUES_PATH)));
+        if (apiPath.matches(VALUES_PATH)) return Optional.of(valuesResponse(consumer));
+        return Optional.empty();
     }
 
-    private TextResponse valuesResponse(HttpRequest request) {
+    private TextResponse valuesResponse(String consumer) {
         try {
-            List<MetricsPacket> metrics =  valuesFetcher.fetch(request.getProperty("consumer"));
+            List<MetricsPacket> metrics =  valuesFetcher.fetch(consumer);
             return new TextResponse(OK, toPrometheusModel(metrics).serialize());
         } catch (JsonRenderingException e) {
             return new TextResponse(INTERNAL_SERVER_ERROR, e.getMessage());