Retrofit+OKHttp 可以很优雅的处理这个问题：

class CommonInterceptor implements Interceptor{
Map<String, String> mCommonParams;

public Response intercept(Chain chain) throws IOException {

if(get){
request = addCommonParamsToUrl(request);
}else if(post){
RequestBody requestBody = request.body();
if(formType){
addCommonparamsToForm(requestBody);
}else if(jsonType){
addCommonParamsToJson(requestBody);
}
...
if (requestBody != null) {
Request.Builder requestBuilder = request.newBuilder();
request = requestBuilder
.post(requestBody)
.build();
}
}
reture request;
}
}