TrUtil.java

package com.braintreegateway.util;

import com.braintreegateway.Configuration;
import com.braintreegateway.Request;

import java.net.URLEncoder;
import java.util.Calendar;
import java.util.Map;
import java.util.TimeZone;

import static com.braintreegateway.util.QueryString.encode;
import static com.braintreegateway.util.QueryString.encodeParam;

public class TrUtil {
    private Configuration configuration;

    public TrUtil(Configuration configuration) {
        this.configuration = configuration;
    }

    public String buildTrData(Request request, String redirectURL) {
        Calendar now = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
        String dateString = String.format("%1$tY%1$tm%1$td%1$tH%1$tM%1$tS", now);

        QueryString trContent = new QueryString()
                .append("api_version", Configuration.apiVersion())
                .append("public_key", configuration.getPublicKey())
                .append("redirect_url", redirectURL)
                .append("time", dateString)
                .append("kind", request.getKind())
                .appendEncodedData(request.toQueryString());

        return new SignatureService(configuration.getPrivateKey(), new Sha1Hasher()).sign(trContent.toString());
    }

    public boolean isValidTrQueryString(String queryString) {
        String[] pieces = queryString.split("&hash=");
        String queryStringWithoutHash = pieces[0];
        String hash = pieces[1];

        return hash.equals(new Sha1Hasher().hmacHash(configuration.getPrivateKey(), queryStringWithoutHash));
    }

    protected String encodeMap(Map<String, String> map) {
        StringBuilder builder = new StringBuilder();

        String[] keys = map.keySet().toArray(new String[0]);
        for (int i = 0; i < keys.length; i++) {
            String key = keys[i];
            builder.append(encodeParam(key, map.get(key)));
            if (i + 1 < keys.length) {
                builder.append("&");
            }
        }
        return builder.toString();
    }

    public String url() {
        return configuration.getBaseURL() + configuration.getMerchantPath() + "/transparent_redirect_requests";
    }
}