some networking refactor

sdk/src/androidTest/java/ly/count/android/sdk/ModuleUserProfileTests.java

@@ -20,9 +20,6 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
 
 @RunWith(AndroidJUnit4.class)
 public class ModuleUserProfileTests {

sdk/src/main/java/ly/count/android/sdk/ConnectionProcessor.java

@@ -21,6 +21,8 @@ of this software and associated documentation files (the "Software"), to deal
 */
 package ly.count.android.sdk;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileInputStream;
@@ -49,6 +51,8 @@ public class ConnectionProcessor implements Runnable {
     private static final int CONNECT_TIMEOUT_IN_MILLISECONDS = 30000;
     private static final int READ_TIMEOUT_IN_MILLISECONDS = 30000;
 
+    private static final String CRLF = "\r\n";
+    private static final String charset = "UTF-8";
     private final StorageProvider storageProvider_;
     private final DeviceIdProvider deviceIdProvider_;
     final ConfigurationProvider configProvider_;
@@ -86,7 +90,7 @@ private enum RequestResult {
         this.healthTracker = healthTracker;
     }
 
-    synchronized public URLConnection urlConnectionForServerRequest(String requestData, final String customEndpoint) throws IOException {
+    synchronized public @NonNull URLConnection urlConnectionForServerRequest(@NonNull String requestData, @Nullable final String customEndpoint) throws IOException {
         String urlEndpoint = "/i";
         if (customEndpoint != null) {
             urlEndpoint = customEndpoint;
@@ -148,8 +152,6 @@ synchronized public URLConnection urlConnectionForServerRequest(String requestDa
             // Just generate some unique random value.
             String boundary = Long.toHexString(System.currentTimeMillis());
             // Line separator required by multipart/form-data.
-            String CRLF = "\r\n";
-            String charset = "UTF-8";
             conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
             OutputStream output = conn.getOutputStream();
             PrintWriter writer = new PrintWriter(new OutputStreamWriter(output, charset), true);
@@ -181,7 +183,7 @@ synchronized public URLConnection urlConnectionForServerRequest(String requestDa
                 conn.setDoOutput(true);
                 conn.setRequestMethod("POST");
                 OutputStream os = conn.getOutputStream();
-                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
+                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, charset));
                 writer.write(requestData);
                 writer.flush();
                 writer.close();