Get ws URI directly from server URL (#30)

* Get ws URI directly from server URL

* extract method

* minor optimization

Author: hermanliang

ParseLiveQuery/src/main/java/com/parse/ParseLiveQueryClient.java

@@ -17,6 +17,10 @@ public interface ParseLiveQueryClient {
 
     class Factory {
 
+        public static ParseLiveQueryClient getClient() {
+            return new ParseLiveQueryClientImpl();
+        }
+
         public static ParseLiveQueryClient getClient(URI uri) {
             return new ParseLiveQueryClientImpl(uri);
         }

ParseLiveQuery/src/main/java/com/parse/ParseLiveQueryClientImpl.java

@@ -7,6 +7,8 @@
 import org.json.JSONObject;
 
 import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Executor;
 
@@ -31,6 +33,10 @@
     private int requestIdCount = 1;
     private boolean userInitiatedDisconnect = false;
 
+    /* package */ ParseLiveQueryClientImpl() {
+        this(getDefaultUri());
+    }
+
     /* package */ ParseLiveQueryClientImpl(URI uri) {
         this(uri, new TubeSockWebSocketClient.TubeWebSocketClientFactory(), Task.BACKGROUND_EXECUTOR);
     }
@@ -45,6 +51,23 @@
         this.webSocketClientCallback = getWebSocketClientCallback();
     }
 
+    private static URI getDefaultUri() {
+        URL serverUrl = ParseRESTCommand.server;
+        if (serverUrl == null) return null;
+        String url = serverUrl.toString();
+        if (serverUrl.getProtocol().equals("https")) {
+            url = url.replaceFirst("https", "wss");
+        } else {
+            url = url.replaceFirst("http", "ws");
+        }
+        try {
+            return new URI(url);
+        } catch (URISyntaxException e) {
+            e.printStackTrace();
+            throw new RuntimeException(e.getMessage());
+        }
+    }
+
     @Override
     public <T extends ParseObject> SubscriptionHandling<T> subscribe(ParseQuery<T> query) {
         int requestId = requestIdGenerator();