Clean up http client when setting a new one.

Author: Justin Steffy

src/main/java/com/orgsync/api/ApiClientImpl.java

@@ -12,7 +12,7 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
-*/
+ */
 package com.orgsync.api;
 
 import java.io.IOException;
@@ -70,7 +70,14 @@
 
     @Override
     public void destroy() {
-        getHttpClient().close();
+        closeHttpClient();
+    }
+
+    private void closeHttpClient() {
+        if (getHttpClient() != null) {
+            getHttpClient().close();
+        }
+
     }
 
     @Override
@@ -85,6 +92,10 @@ public AsyncHttpClient getHttpClient() {
 
     @Override
     public ApiClientImpl setHttpClient(final AsyncHttpClient client) {
+        Util.checkNotNull(client);
+
+        closeHttpClient();
+
         this.client = client;
         return this;
     }

src/test/java/com/orgsync/api/ApiClientImplTest.java

@@ -12,10 +12,11 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
-*/
+ */
 package com.orgsync.api;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -72,6 +73,20 @@ public void testDestroy() {
         verify(http).close();
     }
 
+    @Test
+    public void testSetHttpClient() throws Exception {
+        AsyncHttpClient newClient = mock(AsyncHttpClient.class);
+
+        client.setHttpClient(newClient);
+
+        assertSame(newClient, client.getHttpClient());
+
+        client.destroy();
+
+        verify(http).close();
+        verify(newClient).close();
+    }
+
     @Test
     @SuppressWarnings({ "rawtypes", "unchecked" })
     public void testGetResource() throws Exception {