Master REST-assured: Real‑World Spring Boot 3 API Testing Guide

1. Introduction

This article presents a Spring Boot 3 practical case collection and provides a comprehensive tutorial on using the REST‑assured library to test and validate RESTful APIs.

2. Practical Examples

2.1 Dependency Management

<dependency>
  <groupId>io.rest-assured</groupId>
  <artifactId>rest-assured</artifactId>
  <scope>test</scope>
</dependency>

2.2 Basic GET Request

Send a simple GET request and assert the response status and body values.

import static io.restassured.RestAssured.get;
import static org.hamcrest.Matchers.equalTo;

@Test
public void testApi() {
  get("http://localhost:8080/params/posts/1")
    .then()
    .statusCode(200)
    .body("type", equalTo("posts"))
    .body("id", equalTo(1));
}

2.3 POST Request

@Test
public void testPostApi() throws Throwable {
  JSON Object requestParams = new JSON Object();
  requestParams.put("title", "foo");
  requestParams.put("body", "bar");
  requestParams.put("userId", 1);
  given()
    .header("Content-Type", "application/json")
    .body(requestParams.toString())
    .when()
    .post("http://localhost:8080/params/create")
    .then()
    .statusCode(201)
    .body("title", equalTo("Spring Boot3全家桶实战案例锦集"))
    .body("name", equalTo("pack"))
    .body("uid", equalTo(1));
}

2.4 Adding Headers and Query Parameters

@Test
public void testHeaderAndParam() throws Throwable {
  given()
    .header("Accept", "application/json")
    .queryParam("userId", 1)
    .when()
    .get("http://localhost:8080/params/search")
    .then()
    .statusCode(200)
    .body("size()", greaterThan(0));
}

2.5 Basic Authentication

@Test
public void testAuth() {
  given()
    .auth().basic("root", "pack123")
    .when()
    .get("http://localhost:8080/params/login")
    .then()
    .statusCode(200);
}

2.6 Extracting Values from Response

@Test
public void testGiveValue() {
  Response response = get("http://localhost:8080/params/user/666");
  int userId = response.path("userId");
  String title = response.path("title");
  System.out.println("ID: " + userId);
  System.out.println("头衔: " + title);
}

2.7 XML Data Validation

@Test
public void testXml() {
  get("https://www.w3schools.com/xml/note.xml")
    .then()
    .statusCode(200)
    .body("note.to", equalTo("Tove"))
    .body("note.from", equalTo("Jani"));
}

The XML file used in the test:

Result of the XML validation test:

2.8 File Upload

@Test
public void testUpload() {
  File file = new File("d://Ollama.exe");
  given()
    .multiPart("file", file)
    .when()
    .post("http://localhost:8080/params/upload")
    .then()
    .statusCode(200);
}

2.9 File Download

@Test
public void testDownload() throws Throwable {
  InputStream inputStream = get("http://localhost:8080/resource/1.png").asInputStream();
  FileOutputStream outputStream = new FileOutputStream("1.png");
  byte[] buffer = new byte[1024];
  int bytesRead;
  while ((bytesRead = inputStream.read(buffer)) != -1) {
    outputStream.write(buffer, 0, bytesRead);
  }
  inputStream.close();
  outputStream.close();
}

2.10 DELETE & PUT Requests

// Delete user with ID 1
@Test
public void testDeleteUser() {
  delete("http://localhost:8080/users/1")
    .then()
    .statusCode(200);
}

// Update user information
@Test
public void testUpdateUser() throws Throwable {
  JSON Object requestParams = new JSON Object();
  requestParams.put("title", "pack");
  requestParams.put("body", "xxxooo");
  requestParams.put("userId", 1);
  given()
    .header("Content-Type", "application/json")
    .body(requestParams.toString())
    .when()
    .put("http://localhost:8080/users/1")
    .then()
    .statusCode(200)
    .body("title", equalTo("pack"))
    .body("body", equalTo("xxxooo"))
    .body("uid", equalTo(1));
}

By leveraging REST‑assured, developers can efficiently test and verify their APIs, ensuring reliable operation throughout development cycles.