Best design pattern for API chaining in JAVA

Question

I want to invoke series of API calls in Java. The requirement is that some API's response will be used in the subsequent API call's request. I can achieve this using certain loops. But I want to use a design pattern in such a way that the implementation is generic. Any help?

Chain of responsibility doesn't serve my need as I won't be knowing what is my request context in the beginning.

String out = null;
Response res = execute(req);
out += res.getOut();
req.setXYZ(res.getXYZ);
Response res = execute(req);
out += res.getOut();
req.setABC(res.getABC);
Response res = execute(req);
out += res.getOut();

System.out.println("Final response::"+out);

Answer 1

Thanks all for the inputs, finally I landed on one solution which meets my need. I used one Singleton for the request execution. For each type of command, there will a set of requests to be executed in one particular order. Each command is having a particular order of requests to be executed which I stored in an array with request's unique ID. Then kept the array in a map against command name.

In a loop, I ran the array and executed, after each iteration I keep setting the response back into the request object and eventually prepared the output response.

    private static Map<RequestAction,String[]> actionMap = new HashMap<RequestAction, String[]>();

    static{
    actionMap.put(RequestAction.COMMAND1,new String[]{WebServiceConstants.ONE,WebServiceConstants.TWO,WebServiceConstants.FOUR,WebServiceConstants.THREE});
    actionMap.put(RequestAction.THREE,new String[]{WebServiceConstants.FIVE,WebServiceConstants.ONE,WebServiceConstants.TWO});}


    public Map<String,Object> execute(ServiceParam param) {

    String[] requestChain = getRequestChain(param);

    Map<String,Object> responseMap = new HashMap<String, Object>();


    for(String reqId : requestChain) {

        prepareForProcessing(param, tempMap,responseMap);

        param.getRequest().setReqId(reqId);

        //processing the request
        tempMap = Service.INSTANCE.process(param);

        //prepare responseMap using tempMap         

        param.setResponse(response);

    }

    return responseMap;
}