Add HTTP Proxy support.

README.md

@@ -185,6 +185,16 @@ By default both the Java and Android clients use an `ExecutorService` to perform
 
 Note that once you've shut down the publish executor for a given client, there is no way to restart or replace that executor. You will need to build a new client.
 
+### Using an HTTP proxy
+
+The KeenClient supports HTTP proxies via the `setProxy(String proxyHost, int proxyPort)` and `setProxy(Proxy proxy)` methods of a `KeenClient` instance. Simply use one of those methods after building a client like so:
+
+```java
+KeenClient client = new JavaKeenClientBuilder().build();
+client.setProxy("secureproxy.example.com", 2570);
+// now use the client object as you normally would
+```
+
 ## Working with the Source
 
 ### Using IntelliJ IDEA or Android Studio

core/src/main/java/io/keen/client/java/KeenClient.java

@@ -5,6 +5,8 @@
 import java.io.OutputStreamWriter;
 import java.io.StringReader;
 import java.io.StringWriter;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
 import java.net.URL;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
@@ -585,6 +587,34 @@ public boolean isActive() {
         return isActive;
     }
 
+    /**
+      * Sets an HTTP proxy server configuration for this client.
+      *
+      * @param proxyHost The proxy hostname or IP address.
+      * @param proxyPort The proxy port number.
+      */
+     public void setProxy(String proxyHost, int proxyPort) {
+         this.proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));
+     }
+
+    /**
+      * Sets an HTTP proxy server configuration for this client.
+      *
+      * @param proxy The Proxy object to set.
+      */
+     public void setProxy(Proxy proxy) {
+         this.proxy = proxy;
+     }
+
+    /**
+     * Gets the client Proxy.
+     *
+     * @return the proxy.
+     */
+     public Proxy getProxy() {
+         return proxy;
+     }
+
     ///// PROTECTED ABSTRACT BUILDER IMPLEMENTATION /////
 
     /**
@@ -983,6 +1013,7 @@ private enum ClientSingleton {
     private String baseUrl;
     private GlobalPropertiesEvaluator globalPropertiesEvaluator;
     private Map<String, Object> globalProperties;
+    private Proxy proxy;
 
     ///// PRIVATE METHODS /////
 
@@ -1195,7 +1226,7 @@ public void writeTo(OutputStream out) throws IOException {
 
         // Send the request.
         String writeKey = project.getWriteKey();
-        Request request = new Request(url, "POST", writeKey, source);
+        Request request = new Request(url, "POST", writeKey, source, proxy);
         Response response = httpHandler.execute(request);
 
         // If logging is enabled, log the response.

core/src/main/java/io/keen/client/java/http/Request.java

@@ -1,5 +1,6 @@
 package io.keen.client.java.http;
 
+import java.net.Proxy;
 import java.net.URL;
 
 /**
@@ -16,14 +17,20 @@ public final class Request {
     public final String method;
     public final String authorization;
     public final OutputSource body;
+    public final Proxy proxy;
 
     ///// PUBLIC CONSTRUCTORS /////
 
     public Request(URL url, String method, String authorization, OutputSource body) {
+        this(url, method, authorization, body, null);
+    }
+
+    public Request(URL url, String method, String authorization, OutputSource body, Proxy proxy) {
         this.url = url;
         this.method = method;
         this.authorization = authorization;
         this.body = body;
+        this.proxy = proxy;
     }
 
-}
+}

core/src/main/java/io/keen/client/java/http/UrlConnectionHttpHandler.java

@@ -43,7 +43,12 @@ public Response execute(Request request) throws IOException {
      * @throws IOException If there is an error opening the connection.
      */
     protected HttpURLConnection openConnection(Request request) throws IOException {
-        HttpURLConnection result = (HttpURLConnection) request.url.openConnection();
+        HttpURLConnection result;
+        if (request.proxy != null) {
+            result = (HttpURLConnection) request.url.openConnection(request.proxy);
+        } else {
+            result = (HttpURLConnection) request.url.openConnection();
+        }
         result.setConnectTimeout(DEFAULT_CONNECT_TIMEOUT);
         result.setReadTimeout(DEFAULT_READ_TIMEOUT);
         return result;

core/src/test/java/io/keen/client/java/KeenClientTest.java

@@ -596,4 +596,16 @@ public void onFailure(Exception e) {
         }
     }
 
+    @Test
+    public void testProxy() throws Exception {
+        KeenClient testClient = new TestKeenClientBuilder().build();
+
+        testClient.setProxy("1.2.3.4", 1234);
+        assertNotNull(testClient.getProxy());
+        assertEquals("/1.2.3.4:1234", testClient.getProxy().address().toString());
+
+        testClient.setProxy(null);
+        assertNull(testClient.getProxy());
+    }
+
 }