The invention discloses JAVA object requesting and responding methods, devices and systems, and a terminal. The requesting method comprises the steps of creating a request data structure, a response data structure and a request method structure, invoking the request method structure to obtain a service method in the request data structure and service parameters invoked by the service method, sequentially converting the service parameters into parameters in a JSON (Javascript Serialized Object Notation) format and character string parameters, constructing a request data structure object, assigning the converted character string parameters into the request data structure object, receiving a response data structure object through the response data structure, obtaining response result character string objects in the response data structure object, and sequentially converting the response result character string objects into response result JSON objects and response result JAVA objects. The purpose of invoking the JAVA objects remotely is realized, port service of the original RMI (Remote Method Invocation) can be replaced, the service logic does not need to be modified, and the port performance is improved.