Write first class, make tests and took a coffee to understand freaking cordova-plugin ecosystem

src/android/Webserver.java

@@ -0,0 +1,21 @@
+package org.apache.cordova.plugin;
+
+import org.apache.cordova.api.CordovaPlugin;
+import org.apache.cordova.api.PluginResult;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * This class echoes a string called from JavaScript.
+ */
+public class Webserver extends CordovaPlugin {
+  @Override
+  public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
+    if ("start".equals(action)) {
+        callbackContext.success();
+        return true;
+    }
+    return false;  // Returning false results in a "MethodNotFound" error.
+  }
+}