Spring Boot 4 Microservices & REST APIs · 课时

理解 HTTP 方法与状态码

探索标准 HTTP 方法（GET、POST、PUT、DELETE）以及 REST API 中常见的 HTTP 状态码。

理解 HTTP 方法与状态码 是 CoddyKit 上的免费 Spring Boot 4 Microservices & REST APIs 课时。这是第 3 节课，共 3 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Spring Boot 4 Microservices & REST APIs 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Spring Boot 4 Microservices & REST APIs 课程共包含 3 节课。

本课时的部分内容尚未翻译，以英文显示。

HTTP Methods: The Verbs of REST

HTTP methods are the verbs of REST — they tell the server the action you want on a resource: get, create, update, or delete data.

GET: Retrieving Resources

GET retrieves data. It’s safe and idempotent — repeat it and you get the same result — and it should never modify anything.

public class HttpGetDemo {
  public static void main(String[] args) {
    String resourcePath = "/api/products/123";
    System.out.println("Simulating GET request for: " + resourcePath);
    System.out.println("Expected: Server sends product details.");
  }
}

POST: Creating New Resources

POST sends data to create a new resource. It’s neither safe nor idempotent: each successful POST typically creates another resource.

public class HttpPostDemo {
  public static void main(String[] args) {
    String newProductData = "{\"name\":\"Laptop\", \"price\":1200}";
    System.out.println("Simulating POST request to create resource with data: " + newProductData);
    System.out.println("Expected: Server creates new product and returns its ID.");
  }
}

PUT: Updating Existing Resources

PUT updates an existing resource (or creates it at that URI). It’s idempotent and usually replaces the entire resource with your data.

public class HttpPutDemo {
  public static void main(String[] args) {
    String resourceId = "456";
    String updatedProductData = "{\"name\":\"Gaming Laptop\", \"price\":1500}";
    System.out.println("Simulating PUT request to update resource " + resourceId + " with data: " + updatedProductData);
    System.out.println("Expected: Server fully updates product " + resourceId + ".");
  }
}

DELETE: Removing Resources

DELETE removes a resource. It’s idempotent — delete once and it’s gone; repeat calls may return 404, but the resource stays deleted.

public class HttpDeleteDemo {
  public static void main(String[] args) {
    String resourceId = "789";
    System.out.println("Simulating DELETE request for resource: " + resourceId);
    System.out.println("Expected: Server removes product " + resourceId + ".");
  }
}

HTTP Status Codes: Server's Response

The server replies with an HTTP status code, grouped by class: 1xx info, 2xx success, 3xx redirect, 4xx client error, 5xx server error.

Common 2xx Success Codes

2xx means success: 200 OK (standard), 201 Created (often after POST), and 204 No Content (often after DELETE).

Common 4xx Client Error Codes

4xx means the client erred: 400 Bad Request, 401 Unauthorized, 403 Forbidden, and the famous 404 Not Found.

Common 5xx Server Error Codes

5xx means the server failed: 500 Internal Server Error (generic) and 503 Service Unavailable (overload or maintenance).

Quick Check: Methods & Statuses

Which of the following statements about HTTP methods and status codes are correct?

Recap: Methods & Statuses

You’ve got the REST essentials: methods GET, POST, PUT, DELETE, and status codes grouped 1xx–5xx — the building blocks of any RESTful service.

常见问题解答

「理解 HTTP 方法与状态码」课时是免费的吗？

是的 — 「理解 HTTP 方法与状态码」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Spring Boot 4 Microservices & REST APIs 课程的其余内容，请升级到 CoddyKit PRO。 Spring Boot 4 Microservices & REST APIs 课程共包含 3 节课。

「理解 HTTP 方法与状态码」这节课中我会学到什么？

探索标准 HTTP 方法（GET、POST、PUT、DELETE）以及 REST API 中常见的 HTTP 状态码。你通过在浏览器中直接运行的动手代码来练习 Spring Boot 4 Microservices & REST APIs，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Spring Boot 4 Microservices & REST APIs 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Spring Boot 4 Microservices & REST APIs 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 3 节课，共 3 节。

「理解 HTTP 方法与状态码」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Spring Boot 4 Microservices & REST APIs 课中编写并运行代码吗？

能。每节 Spring Boot 4 Microservices & REST APIs 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

← 返回 Spring Boot 4 Microservices & REST APIs