---

But for this example, we'll use a very simple HTML document with some JavaScript, all inside a long string.

This, of course, is not optimal and you wouldn't use it for production.

In production you would have one of the options above.

But it's the simplest way to focus on the server-side of WebSockets and have a working example:

* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps { #first-steps }

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

### Create a dependency, or "dependable" { #create-a-dependency-or-dependable }

				"application/vnd.anser-web-funds-transfer-initiation",
				"application/vnd.antix.game-component",
				"application/vnd.apple.installer+xml",
				"application/vnd.apple.iwork",
				"application/vnd.apple.keynote",
				"application/vnd.apple.pages",
				"application/vnd.apple.numbers",
				"application/x-tika-iworks-protected",
				"application/vnd.arastra.swi",
				"application/vnd.audiograph",

class MainTest {
  @Test
  fun simple() {
    val request = fromArgs("http://example.com").createRequest()
    assertThat(request.method).isEqualTo("GET")
    assertThat(request.url.toString()).isEqualTo("http://example.com/")
    assertThat(request.body).isNull()
  }

  @Test
  @Throws(IOException::class)
  fun put() {
    val request = fromArgs("-X", "PUT", "-d", "foo", "http://example.com").createRequest()

* `allow_origins` - A list of origins that should be permitted to make cross-origin requests. E.g. `['https://example.org', 'https://www.example.org']`. You can use `['*']` to allow any origin.
* `allow_origin_regex` - A regex string to match against origins that should be permitted to make cross-origin requests. e.g. `'https://.*\.example\.org'`.

curl4j
[![Java CI with Maven](https://github.com/codelibs/curl4j/actions/workflows/maven.yml/badge.svg)](https://github.com/codelibs/curl4j/actions/workflows/maven.yml)
=====

A simple cURL-like Java HTTP client.

## Features

- Fluent API for building HTTP requests (GET, POST, PUT, DELETE, HEAD, OPTIONS, CONNECT, TRACE)
- Support for query parameters, headers, body (String or stream), compression, SSL configuration, proxies, and timeouts

                List.of("                           apple, banana, pear"));
        p2.put("trees", "fir, oak, maple");
        p1.update(p2);

        assertEquals(2, (Object) p1.size());
        Object o23 = p1.getComments("trees");
        assertEquals(List.of("#", "# List of trees", "#"), o23);
        Object o22 = p1.getProperty("trees");
        assertEquals("fir, oak, maple", o22);
        Object o21 = p1.getComments("fruits");

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure { #an-example-file-structure }

Let's say you have a file structure like this:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py

Interceptors
============

Interceptors are a powerful mechanism that can monitor, rewrite, and retry calls. Here's a simple interceptor that logs the outgoing request and the incoming response.

```java
class LoggingInterceptor implements Interceptor {
  @Override public Response intercept(Interceptor.Chain chain) throws IOException {
    Request request = chain.request();

    long t1 = System.nanoTime();

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.