Clean Boundaries for 3rd party APIs

AbstractParseAPI.groovy

package com.quantumaspects

import groovyx.net.http.*
import net.sf.json.JSONArray


abstract class AbstractParseAPI implements ParseAPI {
    
    public Collection retrieve(String parseEntity){
        return retrieveFromParse(parseEntity)
    }
    
    private def retrieveFromParse(String parseEntity) {
        def client = buildRequest()
        def url = (parseEntity == "User")? "users" : "classes/${parseEntity}"
        def response = client.get(path : url)
        JSONArray.toCollection(response.data.results)
    }
    
    private def buildRequest(){
        def http = new RESTClient("${API_URL}")
        http.headers = [ 
                         "X-Parse-Application-Id": applicationId, 
                         "X-Parse-REST-API-Key" : key,
                         "Content-Type" : 'application/json'
                       ]
        return http
    }
}

DatastoreAPI.java

package com.visionarysoftwaresolutions;

import java.util.Collection;

public interface DatastoreAPI {
    Collection retrieve(String parseEntity);
}

ParseAPI.java

package com.visionarysoftwaresolutions;

import java.util.Map;

public interface ParseAPI extends DatastoreAPI {
    final String API_URL = "https://api.parse.com/1/";
    String applicationId = "";
    String key = "";
    
    public String createUser(String username, String password);
    public String createObject(String parseEntity, Map args);
    public String queryForObject(String parseEntity, Map constraints);
    public void pushNotification(String channel, Integer expiry, String type, Map data);
    
}