Spring Boot Test Rest Template

In this tutorial, you'll learn about Fix Spring Boot Test TestRestTemplate Not Working. We cover key concepts, practical examples, and best practices.

The Problem

TestRestTemplate requests fail with authentication or wrong context path.

Quick Fix

Inject @LocalServerPort

Wrong:

int port = 8080;
// Hardcoded port

Output:

Wrong port

Right:

@LocalServerPort
private int port;

Output:

Correct port injected

Use TestRestTemplate

Wrong:

// Not @Autowired

Output:

Template not available

Right:

@Autowired
private TestRestTemplate restTemplate;

Output:

Template injected

Build correct URL

Wrong:

restTemplate.getForObject("/api", String.class)
// Wrong context

Output:

404 Not Found

Right:

restTemplate.getForObject("http://localhost:" + port + "/api", String.class);

Output:

Correct URL

Prevention

• Inject @LocalServerPort for dynamic ports
• Use TestRestTemplate for integration tests
• Set webEnvironment to DEFINED_PORT for fixed port

Common Mistakes with boot test rest template

1. Using head and tail instead of pattern matching, causing runtime errors on empty lists
2. Forgetting that lazy evaluation defers computation until the value is forced, causing space leaks with unevaluated thunks
3. Using return to exit a function early instead of wrapping a pure value in the monad

These mistakes appear frequently in real-world SPRING code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ

This quick fix is part of the DodaTech Spring & JVM ecosystem series. Built by the developers of Doda Browser, DodaZIP, and Durga Antivirus Pro.