public Object invokeSync(final String addr, final Object request, final int timeoutMillis)
                                                                                              throws RemotingException,
                                                                                              InterruptedException {
        ensureStarted();
        check();
        return this.rpcRemoting.invokeSync(addr, request, null, timeoutMillis);
    }
Synchronous invocation using a string address, address format example - 127.0.0.1:12200?key1=value1&key2=value2 <br>
<p>
Notice:<br>
  <ol>
  <li><b>DO NOT modify the request object concurrently when this method is called.</b></li>
  <li>When do invocation, use the string address to find a available client connection, if none then throw exception</li>
  <li>Unlike rpc client, address arguments takes no effect here, for rpc server will not create connection.</li>
  </ol>

@param addr address addr
@param request request request
@param timeoutMillis timeoutMillis timeoutMillis
@return Object
@throws RemotingException remoting exception remoting exception
@throws InterruptedException interrupted exception
src/main/java/com/alipay/remoting/rpc/RpcServer.java