NihRxNormServiceProxy.java

package com.apothesource.pillfill.rxnorm.service;

import com.apothesource.pillfill.rxnorm.datamodel.*;
import com.google.gson.Gson;

import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.List;

/**
 * Default Implementation of the {@link RxNormService} backed by NIH's services
 * http://rxnav.nlm.nih.gov/RxNormAPIs.html
 *
 * Created by Michael Ramirez (michael@pillfill.com) on 7/20/15.
 */
public class NihRxNormServiceProxy implements RxNormService{
    public static final String URL_BASE = "https://rxnav.nlm.nih.gov/REST";
    public static final String URL_FIND_ID_TEMPLATE = URL_BASE + "/rxcui.json?idtype=%s&id=%s&allsrc=%s";
    public static final String URL_FIND_NAME_TEMPLATE =  URL_BASE + "/rxcui.json?name=%s&search=%s";
    public static final String URL_GET_PROPERTIES_TEMPLATE =  URL_BASE + "/rxcui/%s/allProperties.json?prop=%s";
    public static final String URL_GET_RELATED_TEMPLATE = URL_BASE + "/rxcui/%s/allrelated.json";
    public static final String URL_FIND_APPROXIMATE_TEMPLATE = URL_BASE + "/approximateTerm.json?term=%s&maxEntries=%s&option=0";
    public static final String URL_GET_RELATED_BY_TYPE_TEMPLATE = URL_BASE + "/rxcui/%s/related.json?tty=%s";
    public static final String URL_GET_RELATED_BY_REL_TEMPLATE = URL_BASE + "/rxcui/%s/related.json?rela=%s";
    public static final String URL_GET_NDCS_TEMPLATE = URL_BASE + "/rxcui/%s/ndcs.json";
    public static final String URL_GET_BRAND_ING_TEMPLATE = URL_BASE + "/brands.json?ingredientids=%s";

    private final Gson gson = new Gson();

    @Override
    public IdGroupResponse findRxcuiById(IdTypeNames type, String id, int allSrc) throws IOException {
        return getResponseFromNihServer(IdGroupResponse.class,
                URL_FIND_ID_TEMPLATE,
                new String[]{type.toString(), id, "" + allSrc});
    }

    @Override
    public IdGroupResponse findRxcuiByName(String name, int search) throws IOException {
        return getResponseFromNihServer(IdGroupResponse.class,
                URL_FIND_NAME_TEMPLATE,
                new String[]{name, "" + search});
    }

    @Override
    public PropertiesGroupResponse getAllProperties(String id, PropCategoryNames propName) throws IOException {
        return getResponseFromNihServer(PropertiesGroupResponse.class,
                URL_GET_PROPERTIES_TEMPLATE,
                new String[]{id, propName.toString()});
    }

    @Override
    public AllRelatedGroupResponse getAllRelatedInfo(String id) throws IOException{
        return getResponseFromNihServer(AllRelatedGroupResponse.class,
                URL_GET_RELATED_TEMPLATE,
                new String[]{id});
    }

    @Override
    public ApproximateGroupResponse getApproximateMatch(String id, int maxEntries) throws IOException{
        return getResponseFromNihServer(ApproximateGroupResponse.class,
                URL_FIND_APPROXIMATE_TEMPLATE,
                new String[]{id,"" + maxEntries});
    }

    @Override
    public RelatedGroupResponse getRelatedByRelationship(String id, List<RelationshipNames> rela) throws IOException {
        StringBuilder paramBuilder = new StringBuilder();
        for(RelationshipNames rn : rela){
            paramBuilder = paramBuilder.append(rn.toString()).append("+");
        }
        URL url = new URL(String.format(URL_GET_RELATED_BY_REL_TEMPLATE, id, paramBuilder.toString()));
        return getResponseFromNihServer(url, RelatedGroupResponse.class);
    }

    @Override
    public RelatedGroupResponse getRelatedByType(String id, List<TTYNames> ttys) throws IOException {
        StringBuilder paramBuilder = new StringBuilder();
        for(TTYNames tty : ttys){
            paramBuilder = paramBuilder.append(tty.toString()).append("+");
        }
        URL url = new URL(String.format(URL_GET_RELATED_BY_TYPE_TEMPLATE, id, paramBuilder.toString()));
        return getResponseFromNihServer(url, RelatedGroupResponse.class);
    }

    @Override
    public NdcsGroupResponse getNdcs(String id) throws IOException {
        return getResponseFromNihServer(NdcsGroupResponse.class,
                URL_GET_NDCS_TEMPLATE,
                new String[]{id});
    }

    @Override
    public BrandGroupResponse getMultiIngredBrand(List<String> ingredientIds) throws IOException {
        StringBuilder paramBuilder = new StringBuilder();
        for(String id : ingredientIds){
            paramBuilder = paramBuilder.append(id).append("+");
        }
        URL url = new URL(String.format(URL_GET_BRAND_ING_TEMPLATE, paramBuilder.toString()));
        return getResponseFromNihServer(url, BrandGroupResponse.class);
    }

    protected <T> T getResponseFromNihServer(Class<T> classType, String template, String[] parameters) throws IOException{
        for(int i = 0; i < parameters.length; i++){
            parameters[i] = URLEncoder.encode(parameters[i], "UTF-8");
        }
        String urlString = String.format(template, (Object[]) parameters);
        return getResponseFromNihServer(new URL(urlString), classType);
    }

    protected <T> T getResponseFromNihServer(URL url, Class<T> classType) throws IOException{
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        InputStreamReader inputReader = new InputStreamReader(connection.getInputStream());

        T response = gson.fromJson(inputReader, classType);
        inputReader.close();
        return response;
    }
}