Adds ability to configure some HTTP transport behaivior

Author: Chris Wilson

libs/sparkpost-lib/src/main/java/com/sparkpost/Client.java

@@ -34,6 +34,12 @@ public class Client {
 
     private String fromEmail;
 
+    private boolean disconnectAfterRequest = false;
+
+    private int httpConnectTimeout = 0; // 0 - system default
+
+    private int httpReadTimeout = 0; // 0 - system default
+
     public Client() {
     }
 
@@ -78,6 +84,49 @@ public String getFromEmail() {
         return this.fromEmail;
     }
 
+    /**
+     * If true will be more aggressive about disconnecting idle HTTP connections
+     *
+     * @return true
+     */
+    public boolean isDisconnectAfterRequest() {
+        return this.disconnectAfterRequest;
+    }
+
+    /**
+     * If true the underlying HTTP transport will be more aggressive about closing idle HTTP connection so may not resuse TCP sockets as much.
+     *
+     * @param disconnectAfterRequest
+     *            default is false
+     */
+    public void setDisconnectAfterRequest(boolean disconnectAfterRequest) {
+        this.disconnectAfterRequest = disconnectAfterRequest;
+    }
+
+    public int getHttpConnectTimeout() {
+        return this.httpConnectTimeout;
+    }
+
+    /**
+     * Sets a specified timeout value, in milliseconds, to be used
+     * when opening a communications link to the resource referenced
+     * by this URLConnection. If the timeout expires before the
+     * connection can be established, a
+     * java.net.SocketTimeoutException is raised. A timeout of zero is
+     * interpreted as an infinite timeout.
+     **/
+    public void setHttpConnectTimeout(int timeout) {
+        this.httpConnectTimeout = timeout;
+    }
+
+    public int getHttpReadTimeout() {
+        return this.httpReadTimeout;
+    }
+
+    public void setHttpReadTimeout(int httpReadTimeout) {
+        this.httpReadTimeout = httpReadTimeout;
+    }
+
     /**
      * @param fromEmail
      *            the fromEmail to set

libs/sparkpost-lib/src/main/java/com/sparkpost/transport/RestConnection.java

@@ -117,6 +117,9 @@ private HttpURLConnection createConnectionObject(String path, Method method) thr
             // got one of its streams)
             conn = (HttpURLConnection) url.openConnection();
 
+            conn.setConnectTimeout(this.client.getHttpConnectTimeout());
+            conn.setReadTimeout(this.client.getHttpReadTimeout());
+
             if (StringUtils.isNotEmpty(this.client.getAuthKey())) {
                 conn.setRequestProperty("Authorization", this.client.getAuthKey());
             } else if (StringUtils.isNotEmpty(this.client.getUsername()) && StringUtils.isNotEmpty(this.client.getPassword())) {
@@ -412,7 +415,8 @@ private Response doHttpMethod(Endpoint endpoint, Method method, String data, Res
 
             return response;
         } finally {
-            if (conn != null) {
+            if (this.client.isDisconnectAfterRequest() && conn != null) {
+                // Disconnect will more aggressively close idle connections but it is preferred to cache as much as possible
                 conn.disconnect();
             }
         }
@@ -434,7 +438,7 @@ private Response doHttpMethod(String path, Method method, String data, Response
 
             return response;
         } finally {
-            if (conn != null) {
+            if (this.client.isDisconnectAfterRequest() && conn != null) {
                 conn.disconnect();
             }
         }