Calling Spring Boot APIs from Liferay – Step-by-Step Integration Guide

In enterprise applications, it is very common to integrate Liferay Portal with Spring Boot microservices.
A typical use case is when a Liferay portlet or service needs to call an external REST API built using Spring Boot.

In this guide, you will learn:

• how to call Spring Boot APIs from Liferay

• common integration approaches

• step-by-step code examples

• best practices for production

---

🔍 Why Integrate Liferay with Spring Boot?

Liferay is a powerful portal and content platform, while Spring Boot is ideal for building scalable microservices.

Common scenarios:

• Liferay UI calling Spring Boot backend

• Liferay workflows invoking business services

• Headless APIs consumed by Liferay

• External system integration

This architecture keeps:

• Liferay lightweight

• business logic isolated

• services independently scalable

---

🧭 Architecture Overview

---

📊 Diagram 1: Liferay Calling Spring Boot API

---

🚀 Approach 1: Calling Spring Boot API from Liferay Java Code

This is the most common and recommended approach.

---

Step 1: Add HTTP Client Dependency in Liferay

If you are using Liferay DXP 7.2+, you can use:

import com.liferay.portal.kernel.util.HttpUtil;

Or Apache HttpClient (inside OSGi module):

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.5.14</version>
</dependency>

---

Step 2: Call Spring Boot API

String apiUrl = "http://localhost:8080/api/customers";

Http.Options options = new Http.Options();
options.setLocation(apiUrl);
options.setMethod(Http.Method.GET);

String response = HttpUtil.URLtoString(options);
System.out.println("Response: " + response);

---

Step 3: Parse JSON Response

JSONObject json = JSONFactoryUtil.createJSONObject(response);
JSONArray customers = json.getJSONArray("data");

for (int i = 0; i < customers.length(); i++) {
    JSONObject obj = customers.getJSONObject(i);
    System.out.println(obj.getString("name"));
}

---

🚀 Approach 2: Calling Spring Boot API from Liferay Service Builder

Use this when:

• the call is part of a backend service

• multiple portlets reuse it

---

public String fetchCustomerData() {

    String apiUrl = "http://localhost:8080/api/customers";

    Http.Options options = new Http.Options();
    options.setLocation(apiUrl);
    options.setMethod(Http.Method.GET);

    try {
        return HttpUtil.URLtoString(options);
    } catch (Exception e) {
        _log.error("Error calling Spring Boot API", e);
        return null;
    }
}

---

🚀 Approach 3: Calling Spring Boot API from Liferay JavaScript (AJAX)

If Spring Boot exposes CORS-enabled APIs, Liferay frontend can call them directly.

---

fetch("http://localhost:8080/api/customers")
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(err => console.error(err));

⚠️ Use this only for:

• public APIs

• authenticated APIs via tokens

• not for sensitive backend logic

---

🔐 Security Considerations

---

1️⃣ CORS Configuration (Spring Boot)

@CrossOrigin(origins = "http://localhost:8080")
@RestController
public class CustomerController {
}

---

2️⃣ Token-Based Authentication

Pass Authorization header:

options.addHeader("Authorization", "Bearer " + token);

---

3️⃣ HTTPS in Production

Never expose Spring Boot APIs over plain HTTP.

---

🧪 Error Handling & Timeouts

Always handle:

• timeouts

• 4xx / 5xx responses

• network failures

---

options.setTimeout(5000);

try {
    String response = HttpUtil.URLtoString(options);
} catch (Exception e) {
    _log.error("API call failed", e);
}

---

🚨 Common Issues & Fixes

---

❌ CORS Error

Fix: Enable CORS in Spring Boot.

---

❌ Timeout Exception

Fix: Increase timeout.

---

❌ JSON Parse Error

Fix: Validate API response.

---

❌ 401 Unauthorized

Fix: Add Authorization header.

---

✅ Best Practices for Production

✔ Use Service Builder or OSGi services
✔ Add retries and timeouts
✔ Use HTTPS
✔ Secure APIs with OAuth2
✔ Log API calls
✔ Handle failures gracefully
✔ Cache responses where possible

---

📌 Quick Summary (TL;DR)

Goal: Call Spring Boot API from Liferay
Options:

1. Java backend call (recommended)

2. Service Builder integration

3. JavaScript frontend call

Production Tips:
Secure APIs, handle errors, add timeouts.

---

❓ Frequently Asked Questions (FAQ)

---

❓ Can Liferay directly call Spring Boot REST APIs?

Yes, via Java HTTP client or frontend AJAX.

---

❓ Which is better: backend or frontend call?

Backend call is safer and recommended.

---

❓ How do I secure Spring Boot APIs for Liferay?

Use OAuth2 or token-based auth.

---

❓ Can I call Spring Boot APIs from Liferay Workflow?

Yes, using Java service calls.

---

🔗 Related Articles

• Liferay Service Builder Explained

• Liferay OSGi Development Guide

• Spring Boot REST API Best Practices

---

👩‍💻 Final Tip

Always keep business logic in Spring Boot
and presentation in Liferay.

That makes your system scalable and clean.

💼 Professional Support Available

If you are facing issues in real projects related to enterprise backend development or workflow automation, I provide paid consulting, production debugging, project support, and focused trainings.

Technologies covered include Java, Spring Boot, PL/SQL, CMS, Azure, and workflow automation (jBPM, Camunda BPM, RHPAM).

📧 Contact: ishikhanirankari@gmail.com | info@realtechnologiesindia.com

🌐 Website: IT Trainings | Digital metal podium