Optimizing Genesys Cloud Outbound Contact List Validation with Java

What You Will Build

• This application reads raw contact records from a JDBC source, validates emails against RFC 5322, verifies phone numbers using region-specific libphonenumber rules, deduplicates records via composite keys, and batches valid entries into Genesys Cloud.
• It utilizes the official Genesys Cloud Java SDK (genesyscloud) for outbound contact list creation and ingestion.
• The implementation is written in Java 17+ using java.util.concurrent for multi-threaded processing and production-grade error handling.

Prerequisites

• OAuth Client Credentials flow with outbound:contactlist:create and outbound:contactlist:addcontact scopes
• Genesys Cloud Java SDK v11+ (com.genesyscloud:genesyscloud)
• Java 17 runtime with jakarta.mail, com.google.i18n.phonenumbers:libphonenumber, and slf4j
• JDBC driver matching your source database (MySQL, PostgreSQL, or SQL Server)

Authentication Setup

Genesys Cloud requires a bearer token for all API calls. The Java SDK can manage tokens automatically, but explicit caching provides control over refresh cycles and reduces redundant network calls. The following code fetches a token, caches it with an expiration window, and refreshes it before expiry.

import com.genesyscloud.platform.client.ApiClient;
import com.genesyscloud.platform.client.auth.OAuthApi;
import com.genesyscloud.platform.client.auth.model.TokenRequest;
import com.genesyscloud.platform.client.auth.model.TokenResponse;
import java.time.Instant;
import java.util.concurrent.ConcurrentHashMap;

public class TokenManager {
    private final ApiClient apiClient;
    private final String clientId;
    private final String clientSecret;
    private String cachedToken;
    private Instant tokenExpiry;
    private static final long REFRESH_THRESHOLD_SECONDS = 60;

    public TokenManager(ApiClient apiClient, String clientId, String clientSecret) {
        this.apiClient = apiClient;
        this.clientId = clientId;
        this.clientSecret = clientSecret;
        this.tokenExpiry = Instant.now().minusSeconds(1);
    }

    public synchronized String getAccessToken() throws Exception {
        if (cachedToken != null && Instant.now().isBefore(tokenExpiry.minusSeconds(REFRESH_THRESHOLD_SECONDS))) {
            return cachedToken;
        }
        return refreshToken();
    }

    private String refreshToken() throws Exception {
        OAuthApi oauthApi = new OAuthApi(apiClient);
        TokenRequest tokenRequest = new TokenRequest()
                .grantType("client_credentials")
                .clientId(clientId)
                .clientSecret(clientSecret);
        
        TokenResponse response = oauthApi.postOAuthToken(tokenRequest);
        cachedToken = response.getAccessToken();
        tokenExpiry = Instant.now().plusSeconds(response.getExpiresIn());
        return cachedToken;
    }
}

Implementation

Step 1: JDBC Stream & Multi-threaded Reading

Reading large datasets sequentially blocks ingestion. A fixed thread pool partitions the JDBC result set into chunks, allowing parallel validation. The code below demonstrates how to fetch records in batches and submit them to an ExecutorService.

import java.sql.*;
import java.util.*;
import java.util.concurrent.*;

public class ContactProcessor {
    private final ExecutorService validatorPool;
    private final BlockingQueue<Map<String, String>> validContactsQueue;
    private final BlockingQueue<ValidationFailure> errorQueue;
    private final ConcurrentHashMap<String, Boolean> seenKeys = new ConcurrentHashMap<>();

    public ContactProcessor(int threadCount) {
        this.validatorPool = Executors.newFixedThreadPool(threadCount);
        this.validContactsQueue = new LinkedBlockingQueue<>();
        this.errorQueue = new LinkedBlockingQueue<>();
    }

    public void processJdbcSource(Connection jdbcConnection, String query) throws SQLException {
        try (Statement stmt = jdbcConnection.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY)) {
            stmt.setFetchSize(500);
            try (ResultSet rs = stmt.executeQuery(query)) {
                int batchSize = 0;
                List<Map<String, String>> batch = new ArrayList<>(500);
                while (rs.next()) {
                    Map<String, String> record = new HashMap<>();
                    record.put("email", rs.getString("email"));
                    record.put("phone", rs.getString("phone"));
                    record.put("firstName", rs.getString("first_name"));
                    record.put("lastName", rs.getString("last_name"));
                    record.put("sourceId", rs.getString("source_id"));
                    batch.add(record);
                    batchSize++;

                    if (batchSize == 500) {
                        validatorPool.submit(() -> validateBatch(batch));
                        batch.clear();
                        batchSize = 0;
                    }
                }
                if (!batch.isEmpty()) {
                    validatorPool.submit(() -> validateBatch(batch));
                }
            }
        }
    }
}

Step 2: Validation Engine (RFC 5322, libphonenumber, Deduplication)

Each record undergoes three validation stages. Email addresses use jakarta.mail.internet.InternetAddress for strict RFC 5322 compliance. Phone numbers use libphonenumber with a configurable default region. Deduplication relies on a composite key of normalized email and phone. Failures are tagged with a rule identifier for the error report.

import com.google.i18n.phonenumbers.NumberParseException;
import com.google.i18n.phonenumbers.PhoneNumberUtil;
import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;
import jakarta.mail.internet.AddressException;
import jakarta.mail.internet.InternetAddress;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

public class ValidationEngine {
    private static final PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();
    private static final Pattern EMAIL_NORMALIZER = Pattern.compile("[\\s]+");
    private final String defaultRegion;

    public ValidationEngine(String defaultRegion) {
        this.defaultRegion = defaultRegion;
    }

    public void validateBatch(List<Map<String, String>> batch) {
        for (Map<String, String> record : batch) {
            String email = record.get("email");
            String phone = record.get("phone");
            String compositeKey = normalize(email) + "|" + normalize(phone);

            if (!seenKeys.putIfAbsent(compositeKey, Boolean.TRUE)) {
                continue;
            }

            String emailError = validateEmail(email);
            if (emailError != null) {
                reportError(record, "RFC5322_EMAIL_INVALID", emailError);
                continue;
            }

            String phoneError = validatePhone(phone);
            if (phoneError != null) {
                reportError(record, "PHONE_REGION_INVALID", phoneError);
                continue;
            }

            validContactsQueue.add(record);
        }
    }

    private String validateEmail(String email) {
        if (email == null || email.isBlank()) return "Email is empty";
        try {
            InternetAddress address = new InternetAddress(email);
            address.validate();
            return null;
        } catch (AddressException e) {
            return "RFC 5322 violation: " + e.getMessage();
        }
    }

    private String validatePhone(String phone) {
        if (phone == null || phone.isBlank()) return "Phone is empty";
        try {
            PhoneNumber number = phoneUtil.parse(phone, defaultRegion);
            if (!phoneUtil.isValidNumber(number)) {
                return "Invalid phone number for region " + defaultRegion;
            }
            return null;
        } catch (NumberParseException e) {
            return "Phone parsing failed: " + e.getMessage();
        }
    }

    private String normalize(String value) {
        if (value == null) return "";
        return EMAIL_NORMALIZER.matcher(value.trim().toLowerCase()).replaceAll("");
    }

    private void reportError(Map<String, String> record, String rule, String message) {
        errorQueue.add(new ValidationFailure(record.get("sourceId"), rule, message));
    }
}

Step 3: Batching Valid Contacts for API Ingestion

Genesys Cloud limits contact ingestion requests to 1000 records per call. The SDK handles serialization, but you must structure the request correctly. The following code drains the valid queue, chunks it, and submits it to the OutboundApi. It includes explicit 429 handling with Retry-After parsing.

HTTP Equivalent for reference:

POST /api/v2/outbound/contactlists/{contactListId}/contacts
Authorization: Bearer <token>
Content-Type: application/json

[
  {
    "email": "user@example.com",
    "address": "+14155552671",
    "firstName": "John",
    "lastName": "Doe"
  }
]

Response 201 Created
{
  "id": "contact-list-id",
  "contacts": [
    { "id": "new-contact-id", "email": "user@example.com", "address": "+14155552671" }
  ]
}

import com.genesyscloud.platform.client.outbound.OutboundApi;
import com.genesyscloud.platform.client.outbound.model.ContactListContact;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class ContactIngestor {
    private final OutboundApi outboundApi;
    private final String contactListId;
    private final TokenManager tokenManager;
    private final BlockingQueue<Map<String, String>> validQueue;
    private static final int BATCH_SIZE = 500;

    public ContactIngestor(OutboundApi outboundApi, String contactListId, TokenManager tokenManager, BlockingQueue<Map<String, String>> validQueue) {
        this.outboundApi = outboundApi;
        this.contactListId = contactListId;
        this.tokenManager = tokenManager;
        this.validQueue = validQueue;
    }

    public void ingestBatch() throws Exception {
        List<ContactListContact> batch = new ArrayList<>(BATCH_SIZE);
        while (true) {
            Map<String, String> record = validQueue.poll(100, TimeUnit.MILLISECONDS);
            if (record == null && validQueue.isEmpty()) break;
            if (record != null) {
                batch.add(new ContactListContact()
                        .email(record.get("email"))
                        .address(record.get("phone"))
                        .firstName(record.get("firstName"))
                        .lastName(record.get("lastName")));
            }
            if (batch.size() == BATCH_SIZE) {
                submitBatch(batch);
                batch.clear();
            }
        }
        if (!batch.isEmpty()) {
            submitBatch(batch);
        }
    }

    private void submitBatch(List<ContactListContact> batch) throws Exception {
        int retries = 3;
        Exception lastException = null;
        
        for (int attempt = 1; attempt <= retries; attempt++) {
            try {
                outboundApi.postOutboundContactlistsContactlistIdContacts(
                    contactListId, batch, null, null, null, null, null
                );
                return;
            } catch (com.genesyscloud.platform.client.ApiException e) {
                if (e.getCode() == 429) {
                    long retryAfter = parseRetryAfter(e.getResponseHeaders().get("Retry-After"));
                    Thread.sleep(retryAfter * 1000);
                    continue;
                }
                throw e;
            }
        }
        throw new RuntimeException("Failed to ingest batch after " + retries + " attempts", lastException);
    }

    private long parseRetryAfter(String header) {
        if (header == null || header.isBlank()) return 1;
        try {
            return Long.parseLong(header);
        } catch (NumberFormatException e) {
            return 1;
        }
    }
}

Step 4: Error Report Generation

The validation engine collects failures in a thread-safe queue. After ingestion completes, the application serializes these failures into a structured report. Each entry maps the source record to the exact validation rule that triggered rejection.

import java.io.FileWriter;
import java.io.PrintWriter;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;

public class ErrorReporter {
    private final BlockingQueue<ValidationFailure> errorQueue;

    public ErrorReporter(BlockingQueue<ValidationFailure> errorQueue) {
        this.errorQueue = errorQueue;
    }

    public void generateReport(String outputPath) throws Exception {
        try (PrintWriter writer = new PrintWriter(new FileWriter(outputPath))) {
            writer.println("SourceId,Rule,Message");
            ValidationFailure failure;
            while ((failure = errorQueue.poll(100, TimeUnit.MILLISECONDS)) != null) {
                writer.printf("%s,%s,%s%n", 
                    escapeCsv(failure.sourceId), 
                    failure.rule, 
                    escapeCsv(failure.message));
            }
            writer.flush();
        }
    }

    private String escapeCsv(String value) {
        if (value == null) return "";
        if (value.contains(",") || value.contains("\"") || value.contains("\n")) {
            return "\"" + value.replace("\"", "\"\"") + "\"";
        }
        return value;
    }
}

class ValidationFailure {
    final String sourceId;
    final String rule;
    final String message;

    ValidationFailure(String sourceId, String rule, String message) {
        this.sourceId = sourceId;
        this.rule = rule;
        this.message = message;
    }
}

Complete Working Example

The following module combines all components into a single executable class. Replace the JDBC URL, credentials, and Genesys Cloud parameters before running.

import com.genesyscloud.platform.client.ApiClient;
import com.genesyscloud.platform.client.auth.OAuthApi;
import com.genesyscloud.platform.client.auth.model.TokenRequest;
import com.genesyscloud.platform.client.auth.model.TokenResponse;
import com.genesyscloud.platform.client.outbound.OutboundApi;
import com.genesyscloud.platform.client.outbound.model.ContactListPost;
import com.genesyscloud.platform.client.outbound.model.ContactListType;
import com.genesyscloud.platform.client.outbound.model.ContactList;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.time.Instant;
import java.util.concurrent.*;

public class GenesysContactValidator {
    public static void main(String[] args) {
        // Configuration
        String jdbcUrl = "jdbc:postgresql://db-host:5432/crm_db";
        String jdbcUser = "db_user";
        String jdbcPass = "db_password";
        String genesysHost = "https://mycompany.mypurecloud.com";
        String clientId = "your-client-id";
        String clientSecret = "your-client-secret";
        String defaultRegion = "US";
        int threadCount = 8;
        String reportPath = "validation_errors.csv";

        try {
            // 1. Initialize API Client & Auth
            ApiClient apiClient = ApiClient.init();
            apiClient.setBasePath(genesysHost);
            TokenManager tokenManager = new TokenManager(apiClient, clientId, clientSecret);
            apiClient.setAccessToken(tokenManager.getAccessToken());

            // 2. Create Contact List
            OutboundApi outboundApi = new OutboundApi(apiClient);
            ContactListPost listPost = new ContactListPost()
                    .name("Validated_Outbound_List")
                    .type(ContactListType.UPLOADABLE)
                    .description("Auto-validated via JDBC pipeline");
            ContactList createdList = outboundApi.postOutboundContactlists(listPost);
            System.out.println("Created contact list: " + createdList.getId());

            // 3. Initialize Processing Components
            BlockingQueue<Map<String, String>> validQueue = new LinkedBlockingQueue<>();
            BlockingQueue<ValidationFailure> errorQueue = new LinkedBlockingQueue<>();
            ContactProcessor processor = new ContactProcessor(threadCount);
            ValidationEngine engine = new ValidationEngine(defaultRegion);
            ContactIngestor ingestor = new ContactIngestor(outboundApi, createdList.getId(), tokenManager, validQueue);
            ErrorReporter reporter = new ErrorReporter(errorQueue);

            // 4. Execute Pipeline
            Connection jdbcConn = DriverManager.getConnection(jdbcUrl, jdbcUser, jdbcPass);
            processor.processJdbcSource(jdbcConn, "SELECT source_id, email, phone, first_name, last_name FROM raw_contacts");
            jdbcConn.close();

            // Wait for validation to finish
            processor.validatorPool.shutdown();
            processor.validatorPool.awaitTermination(10, TimeUnit.MINUTES);

            // Ingest valid contacts
            ingestor.ingestBatch();

            // Generate error report
            reporter.generateReport(reportPath);
            System.out.println("Pipeline complete. Errors written to " + reportPath);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: The OAuth token is expired, malformed, or the client credentials are incorrect.
• How to fix it: Verify that clientId and clientSecret match a Genesys Cloud OAuth client. Ensure the TokenManager refreshes the token before expiry. Check that the API client base path matches your Genesys Cloud organization URL.
• Code showing the fix: The TokenManager class above implements a 60-second refresh threshold to prevent mid-request expiration.

Error: 403 Forbidden

• What causes it: The OAuth client lacks the required scopes for outbound operations.
• How to fix it: Navigate to the Genesys Cloud admin console, open the OAuth client configuration, and add outbound:contactlist:create and outbound:contactlist:addcontact. Regenerate the token after scope changes.
• Code showing the fix: No code change is required. Scope enforcement occurs at the API gateway. Verify the TokenRequest uses client_credentials grant type.

Error: 429 Too Many Requests

• What causes it: The Genesys Cloud API enforces rate limits per tenant and per API endpoint. Rapid batch submissions trigger this limit.
• How to fix it: Implement exponential backoff using the Retry-After header. The ContactIngestor class parses this header and sleeps before retrying. Reduce BATCH_SIZE to 250 if limits persist.
• Code showing the fix: The submitBatch method in ContactIngestor catches ApiException with code 429, extracts Retry-After, and retries up to three times.

Error: RFC5322_EMAIL_INVALID or PHONE_REGION_INVALID

• What causes it: Source data contains malformed characters, missing country codes, or non-standard formatting.
• How to fix it: Review the generated CSV error report. Clean the source database or add preprocessing rules before JDBC extraction. Ensure defaultRegion matches the primary geographic target of the campaign.
• Code showing the fix: The ValidationEngine normalizes inputs and uses strict parsers. Adjust the defaultRegion parameter in the constructor if phone validation fails for international numbers.

Official References

• Genesys Cloud Outbound Contact List API Documentation
• Genesys Cloud Java SDK Reference
• libphonenumber Java Documentation
• RFC 5322 Internet Message Format