@@ -0,0 +1,196 @@
+package com.ouc.cs;%0A%0Apublic class EchoServiceImpl implements EchoService %7B%0A   @Override%0A   public String echo(String ping) %7B%0A%09   return ping != null ? ping + %22 --%3E I am ok.%22 : %22 I am ok.%22;%0A   %7D%0A%7D%0A

Create EchoServiceImpl.java