Testing POST APIs using Spring Boot TestRestTemplate

Learn to consume HTTP POST REST API with Spring TestRestTemplate. In this post request test example, we will be sending request body along with request headers.

1. Maven dependencies

Make sure, you have spring-boot-starter-test dependency in your project to get access to TestRestTemplate class in runtime. If you are using the @SpringBootTest annotation, a TestRestTemplate is automatically available and can be @Autowired into your test.

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-test</artifactId>
	<scope>test</scope>
</dependency>

2. HTTP POST API

We are using the code base of Spring boot 2 rest example. The POST API is given as below.

1. It adds an employee in the employees collection.
2. It accept employee data in Employee object.
3. It accepts and creates JSON meda type.
4. It accepts two HTTP headers i.e. X-COM-PERSIST and X-COM-LOCATION. First header is required and second header is optional.
5. It returns the location of resource created.

package com.howtodoinjava.rest.controller;

import java.net.URI;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import com.howtodoinjava.rest.dao.EmployeeDAO;
import com.howtodoinjava.rest.model.Employee;
import com.howtodoinjava.rest.model.Employees;

@RestController
@RequestMapping(path = "/employees")
public class EmployeeController 
{
    @Autowired
    private EmployeeDAO employeeDao;
     
    @PostMapping(path= "/", consumes = "application/json", produces = "application/json")
    public ResponseEntity<Object> addEmployee(
                        @RequestHeader(name = "X-COM-PERSIST", required = true) String headerPersist,
                        @RequestHeader(name = "X-COM-LOCATION", required = false, defaultValue = "ASIA") String headerLocation,
                        @RequestBody Employee employee) 
                 throws Exception 
    {       
        //Generate resource id
        Integer id = employeeDao.getAllEmployees().getEmployeeList().size() + 1;
        employee.setId(id);
        
        //add resource
        employeeDao.addEmployee(employee);
        
        //Create resource location
        URI location = ServletUriComponentsBuilder.fromCurrentRequest()
                                    .path("/{id}")
                                    .buildAndExpand(employee.getId())
                                    .toUri();
        
        //Send location in response
        return ResponseEntity.created(location).build();
    }
}

I am not going to discuss other classes as it is not related to rest api testing. You can download the sourcecode and see to understand more.

3. Spring TestRestTemplate

To test POST API, we need to create spring boot test class annotated with @SpringBootTest.

package com.howtodoinjava.rest;

import java.net.URI;
import java.net.URISyntaxException;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.test.context.junit4.SpringRunner;

import com.howtodoinjava.rest.model.Employee;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)
public class SpringBootDemoApplicationTests 
{
    @Autowired
    private TestRestTemplate restTemplate;
    
    @LocalServerPort
    int randomServerPort;

    @Test
    public void testAddEmployeeSuccess() throws URISyntaxException 
    {
        final String baseUrl = "http://localhost:"+randomServerPort+"/employees/";
        URI uri = new URI(baseUrl);
        Employee employee = new Employee(null, "Adam", "Gilly", "[email protected]");
        
        HttpHeaders headers = new HttpHeaders();
        headers.set("X-COM-PERSIST", "true");      

        HttpEntity<Employee> request = new HttpEntity<>(employee, headers);
        
        ResponseEntity<String> result = this.restTemplate.postForEntity(uri, request, String.class);
        
        //Verify request succeed
        Assert.assertEquals(201, result.getStatusCodeValue());
    }
    
    @Test
    public void testAddEmployeeMissingHeader() throws URISyntaxException 
    {
        final String baseUrl = "http://localhost:"+randomServerPort+"/employees/";
        URI uri = new URI(baseUrl);
        Employee employee = new Employee(null, "Adam", "Gilly", "[email protected]");
        
        HttpHeaders headers = new HttpHeaders();

        HttpEntity<Employee> request = new HttpEntity<>(employee, headers);
        
        ResponseEntity<String> result = this.restTemplate.postForEntity(uri, request, String.class);
        
        //Verify bad request and missing header
        Assert.assertEquals(400, result.getStatusCodeValue());
        Assert.assertEquals(true, result.getBody().contains("Missing request header"));
    }

}

4. Spring boot TestRestTemplate POST example – Demo

Execute the test class as JUnit test. It will start the server and deploy the API as it will be done normally. Then It will execute the tests.

You can verify the tests in JUnit tab.

Let me know if you have a query in this spring boot TestRestTemplate postForEntity() example.

Happy Learning !!