auth0-java-mvc-common

name	auth0-java-mvc-common
description	Use when adding Auth0 login, logout, and callback handling to Java Servlet web applications - integrates com.auth0:mvc-auth-commons SDK for server-side Java apps using javax.servlet with session-based authentication. Triggers on AuthenticationController, AuthorizeUrl, Tokens, IdentityVerificationException, Java MVC auth.
license	MIT
metadata	{"author":"Auth0 <[e-mail]>"}

Auth0 Java MVC Common Integration

Add Auth0 authentication to Java Servlet web applications using com.auth0:mvc-auth-commons. Provides AuthenticationController for building authorize URLs and handling callbacks, with session-based authentication and support for Organizations and Multiple Custom Domains.

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Agent instruction: Before providing SDK setup instructions, fetch the latest release version by running:

gh api repos/auth0/auth0-java-mvc-common/releases/latest --jq '.tag_name'

Use the returned version in all dependency lines instead of any hardcoded version below. If the API call fails, use 1.12.0.

Prerequisites

• Java 8+ (Java 17+ recommended)
• Servlet container (Tomcat, Jetty, etc.) with javax.servlet 3+
• Maven 3.6+ or Gradle 7+
• Auth0 Regular Web Application configured
• If you don't have Auth0 set up yet, use the auth0-quickstart skill first

When NOT to Use

Use Case	Recommended Skill
Spring Boot web applications with auto-configuration	Use Spring Boot + Okta starter for auto-configured Spring Boot login
Spring Boot REST APIs (stateless JWT)	Use auth0-springboot-api for JWT Bearer token validation
Single Page Applications	Use auth0-react, auth0-vue, or auth0-angular for client-side auth
Mobile applications	Use auth0-android or auth0-swift for native mobile
Machine-to-machine API calls	Use Auth0 Management API SDK for server-to-server

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Quick Start Workflow

Agent instruction: If the user's prompt already provides Auth0 credentials (domain, client ID, client secret), use them directly — skip the bootstrap script and credential questions. Only offer setup options when credentials are missing.

1. Install SDK

Gradle (build.gradle):

implementation 'com.auth0:mvc-auth-commons:1.12.0'

Maven (pom.xml):

<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>mvc-auth-commons</artifactId>
    <version>1.12.0</version>
</dependency>

2. Create Auth0 Application

You need a Regular Web Application (not SPA or Native) in Auth0.

STOP — ask the user before proceeding.

Ask exactly this question and wait for their answer before doing anything else:

"How would you like to create the Auth0 application?

1. Automated — I'll run Auth0 CLI scripts that create the application and write the values to your config automatically.
2. Manual — You create the application yourself in the Auth0 Dashboard (or via auth0 apps create) and provide me the Domain, Client ID, and Client Secret.

Which do you prefer? (1 = Automated / 2 = Manual)"

Do NOT proceed to any setup steps until the user has answered. Do NOT default to manual.

If the user chose Automated, follow the Setup Guide for complete CLI scripts. The automated path writes configuration for you — skip Step 3 below and proceed directly to Step 4.

If the user chose Manual, follow the Setup Guide (Manual Setup section). Then continue with Step 3.

Quick reference for manual application creation:

# Using Auth0 CLI
auth0 apps create \
  --name "My Java Web App" \
  --type regular \
  --callbacks http://localhost:3000/callback \
  --logout-urls http://localhost:3000

Or create manually in Auth0 Dashboard → Applications → Applications → Create Application → Regular Web Applications

3. Configure Credentials

Store credentials as environment variables (never hardcode in source):

export AUTH0_DOMAIN="your-tenant.auth0.com"
export AUTH0_CLIENT_ID="your-client-id"
export AUTH0_CLIENT_SECRET="your-client-secret"

Or use a .env file (add to .gitignore):

AUTH0_DOMAIN=your-tenant.auth0.com
AUTH0_CLIENT_ID=your-client-id
AUTH0_CLIENT_SECRET=your-client-secret

Agent instruction: Java does not auto-load .env files. System.getenv() only reads OS-level environment variables. If you generate a .env file, you must also either: (1) add dotenv-java as a dependency and use Dotenv.load().get("AUTH0_DOMAIN") instead of System.getenv(), or (2) instruct the user to run source .env before starting the server. Do not generate code that uses both a .env file and System.getenv() without a loading mechanism — the values will be null.

Important: Domain must NOT include https://. The library constructs the issuer URL automatically.

4. Initialize AuthenticationController

Create a singleton AuthenticationController instance:

import com.auth0.AuthenticationController;
import com.auth0.jwk.JwkProviderBuilder;
import com.auth0.jwk.JwkProvider;

public class Auth0Config {

    private static final AuthenticationController controller = createController();

    private static AuthenticationController createController() {
        String domain = System.getenv("AUTH0_DOMAIN");
        String clientId = System.getenv("AUTH0_CLIENT_ID");
        String clientSecret = System.getenv("AUTH0_CLIENT_SECRET");

        JwkProvider jwkProvider = new JwkProviderBuilder(domain).build();

        return AuthenticationController.newBuilder(domain, clientId, clientSecret)
            .withJwkProvider(jwkProvider)
            .build();
    }

    public static AuthenticationController getAuthController() {
        return controller;
    }
}

5. Create Login Servlet

import com.auth0.AuthenticationController;
import com.auth0.AuthorizeUrl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(urlPatterns = {"/login"})
public class LoginServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        AuthenticationController controller = Auth0Config.getAuthController();

        // Build callback URL — omit port for standard ports (80/443) to avoid
        // mismatch with the URL registered in Auth0 Dashboard, especially behind proxies.
        String scheme = request.getScheme();
        int port = request.getServerPort();
        String redirectUrl = scheme + "://" + request.getServerName()
            + ((port == 80 || port == 443) ? "" : ":" + port) + "/callback";

        AuthorizeUrl authorizeUrl = controller.buildAuthorizeUrl(request, response, redirectUrl)
            .withScope("openid profile email");

        response.sendRedirect(authorizeUrl.build());
    }
}

6. Create Callback Servlet

import com.auth0.AuthenticationController;
import com.auth0.IdentityVerificationException;
import com.auth0.Tokens;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(urlPatterns = {"/callback"})
public class CallbackServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        AuthenticationController controller = Auth0Config.getAuthController();

        try {
            Tokens tokens = controller.handle(request, response);

            request.getSession().setAttribute("accessToken", tokens.getAccessToken());
            request.getSession().setAttribute("idToken", tokens.getIdToken());

            response.sendRedirect("/dashboard");
        } catch (IdentityVerificationException e) {
            response.sendRedirect("/login?error=" + e.getCode());
        }
    }
}

7. Protect Routes with Authentication Middleware (Servlet Filter)

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebFilter(urlPatterns = {"/dashboard/*", "/api/private/*"})
public class AuthenticationFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        HttpSession session = request.getSession(false);

        if (session == null || session.getAttribute("idToken") == null) {
            response.sendRedirect("/login");
            return;
        }

        chain.doFilter(req, res);
    }

    @Override
    public void init(FilterConfig filterConfig) {}

    @Override
    public void destroy() {}
}

8. Test Application

Agent instruction: After writing all code, verify the build succeeds:

./gradlew build

or mvn package. If build fails, diagnose and fix. After 5-6 failed attempts, use AskUserQuestion to get help.

1. Start the application and navigate to http://localhost:3000/login
2. You should be redirected to the Auth0 Universal Login page
3. After login, the callback servlet handles the response and redirects to /dashboard

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Common Mistakes

Mistake	Fix
Domain includes https://	Use your-tenant.auth0.com format only — no scheme prefix
Client secret hardcoded in source	Use environment variables or .env file, add to .gitignore
Created SPA or Native app instead of Regular Web	Must create Regular Web Application in Auth0 Dashboard
Callback URL mismatch	Callback URL in code must exactly match what's registered in Auth0 Dashboard
Missing openid scope	Always include openid in the scope — required for ID token
Not handling IdentityVerificationException	Always catch this in the callback handler to show login errors
Using response_type=token	Regular web apps must use code flow (the default) — never implicit
Session not invalidated on logout	Call request.getSession().invalidate() before redirecting to Auth0 logout

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Scope and Audience Configuration

See Integration Guide for requesting custom scopes, audience for API access tokens, and Organizations support.

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Multiple Custom Domains (MCD)

Built-in support for routing users to the correct Auth0 domain via DomainResolver. See Integration Guide for configuration.

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Related Skills

• auth0-quickstart — Basic Auth0 setup and account creation
• auth0-springboot-api — Spring Boot REST APIs with JWT Bearer token validation

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Quick Reference

Core Classes:

• AuthenticationController — Main entry point, builds authorize URLs and handles callbacks
• AuthenticationController.Builder — Configures the controller via newBuilder(domain, clientId, clientSecret)
• AuthorizeUrl — Fluent builder for /authorize URL parameters
• Tokens — Access token, ID token, refresh token from callback
• IdentityVerificationException — Authentication error with error code
• DomainResolver — Interface for Multiple Custom Domain support

Builder Methods (AuthorizeUrl):

• .withScope("openid profile email") — Set requested scopes
• .withAudience("https://my-api") — Request API access token
• .withOrganization("org_xxx") — Lock to specific Organization
• .withInvitation("invite_xxx") — Accept Organization invitation
• .withConnection("google-oauth2") — Skip to specific connection
• .withParameter("key", "value") — Add custom authorize parameter

Token Access (Tokens):

• tokens.getAccessToken() — Access token string
• tokens.getIdToken() — ID token (JWT) string
• tokens.getRefreshToken() — Refresh token (if offline_access scope requested)
• tokens.getExpiresIn() — Token expiration in seconds
• tokens.getType() — Token type (usually "Bearer")
• tokens.getDomain() — Auth0 domain that issued the tokens
• tokens.getIssuer() — Token issuer URL

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Detailed Documentation

• Setup Guide — Auth0 CLI automation, environment configuration, secret management
• Integration Guide — Organizations, MCD, custom scopes, logout, error handling, advanced patterns
• API Reference — Complete configuration options, builder methods, claims reference, testing checklist

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References

• Auth0 Java Web App Quickstart
• SDK GitHub Repository
• Auth0 Universal Login
• Authorization Code Flow
• Auth0 Organizations