Add cellular network warning

app/src/main/java/com/hippo/network/Network.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2014 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * 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.hippo.network;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+
+public final class Network {
+    private Network() {}
+
+    public static int getActiveNetworkType(Context context) {
+        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
+        if (activeNetwork != null) {
+            return activeNetwork.getType();
+        } else {
+            return -1;
+        }
+    }
+}