发送请求

你可以使用Guzzle的 GuzzleHttp\ClientInterface 对象来发送请求。

创建客户端

1. use GuzzleHttp\Client;

3. $client = new Client([
4. // Base URI is used with relative requests
5. 'base_uri' => 'http://httpbin.org',
6. // You can set any number of default request options.
7. 'timeout'  => 2.0,
8. ]);

Client对象可以接收一个包含参数的数组：

base_uri

(string|UriInterface) 基URI用来合并到相关URI，可以是一个字符串或者UriInterface的实例，当提供了相关uri，将合并到基URI，遵循的规则请参考 RFC 3986, section 2 章节。

1. // Create a client with a base URI
2. $client = new GuzzleHttp\Client(['base_uri' => 'https://foo.com/api/']);
3. // Send a request to https://foo.com/api/test
4. $response = $client->request('GET', 'test');
5. // Send a request to https://foo.com/root
6. $response = $client->request('GET', '/root');

不想阅读RFC 3986？这里有一些关于 base_uri 与其他URI处理器的快速例子：

handler

传输HTTP请求的(回调)函数。 该函数被调用的时候包含 Psr7\Http\Message\RequestInterface 以及参数数组，必须返回 GuzzleHttp\Promise\PromiseInterface ，成功时满足 Psr7\Http\Message\ResponseInterface 。 handler 是一个构造方法，不能在请求参数里被重写。

...

(混合) 构造方法中传入的其他所有参数用来当作每次请求的默认参数。

发送请求

Client对象的方法可以很容易的发送请求：

1. $response = $client->get('http://httpbin.org/get');
2. $response = $client->delete('http://httpbin.org/delete');
3. $response = $client->head('http://httpbin.org/get');
4. $response = $client->options('http://httpbin.org/get');
5. $response = $client->patch('http://httpbin.org/patch');
6. $response = $client->post('http://httpbin.org/post');
7. $response = $client->put('http://httpbin.org/put');

你可以创建一个请求，一切就绪后将请求传送给client：

1. use GuzzleHttp\Psr7\Request;

3. $request = new Request('PUT', 'http://httpbin.org/put');
4. $response = $client->send($request, ['timeout' => 2]);

Client对象为传输请求提供了非常灵活的处理器方式，包括请求参数、每次请求使用的中间件以及传送多个相关请求的基URI。

你可以在 Handlers and Middleware 页面找到更多关于中间件的内容。

异步请求

你可以使用Client提供的方法来创建异步请求：

1. $promise = $client->getAsync('http://httpbin.org/get');
2. $promise = $client->deleteAsync('http://httpbin.org/delete');
3. $promise = $client->headAsync('http://httpbin.org/get');
4. $promise = $client->optionsAsync('http://httpbin.org/get');
5. $promise = $client->patchAsync('http://httpbin.org/patch');
6. $promise = $client->postAsync('http://httpbin.org/post');
7. $promise = $client->putAsync('http://httpbin.org/put');

你也可以使用Client的 sendAsync() and requestAsync() 方法：

1. use GuzzleHttp\Psr7\Request;

3. // Create a PSR-7 request object to send
4. $headers = ['X-Foo' => 'Bar'];
5. $body = 'Hello!';
6. $request = new Request('HEAD', 'http://httpbin.org/head', $headers, $body);

8. // Or, if you don't need to pass in a request instance:
9. $promise = $client->requestAsync('GET', 'http://httpbin.org/get');

这些方法返回了Promise对象，该对象实现了由 Guzzle promises library 提供的 Promises/A+ spec ，这意味着你可以使用 then() 来调用返回值，成功使用 Psr\Http\Message\ResponseInterface 处理器，否则抛出一个异常。

1. use Psr\Http\Message\ResponseInterface;
2. use GuzzleHttp\Exception\RequestException;

4. $promise = $client->requestAsync('GET', 'http://httpbin.org/get');
5. $promise->then(
6. function (ResponseInterface $res) {
7. echo $res->getStatusCode() . "\n";
8. },
9. function (RequestException $e) {
10. echo $e->getMessage() . "\n";
11. echo $e->getRequest()->getMethod();
12. }
13. );

并发请求

你可以使用Promise和异步请求来同时发送多个请求：

1. use GuzzleHttp\Client;
2. use GuzzleHttp\Promise;

4. $client = new Client(['base_uri' => 'http://httpbin.org/']);

6. // Initiate each request but do not block
7. $promises = [
8. 'image' => $client->getAsync('/image'),
9. 'png'   => $client->getAsync('/image/png'),
10. 'jpeg'  => $client->getAsync('/image/jpeg'),
11. 'webp'  => $client->getAsync('/image/webp')
12. ];

14. // Wait on all of the requests to complete.
15. $results = Promise\unwrap($promises);

17. // You can access each result using the key provided to the unwrap
18. // function.
19. echo $results['image']->getHeader('Content-Length');
20. echo $results['png']->getHeader('Content-Length');

当你想发送不确定数量的请求时，可以使用 GuzzleHttp\Pool 对象：

1. use GuzzleHttp\Pool;
2. use GuzzleHttp\Client;
3. use GuzzleHttp\Psr7\Request;

5. $client = new Client();

7. $requests = function ($total) {
8. $uri = 'http://127.0.0.1:8126/guzzle-server/perf';
9. for ($i = 0; $i < $total; $i++) {
10. yield new Request('GET', $uri);
11. }
12. };

14. $pool = new Pool($client, $requests(100), [
15. 'concurrency' => 5,
16. 'fulfilled' => function ($response, $index) {
17. // this is delivered each successful response
18. },
19. 'rejected' => function ($reason, $index) {
20. // this is delivered each failed request
21. },
22. ]);

24. // Initiate the transfers and create a promise
25. $promise = $pool->promise();

27. // Force the pool of requests to complete.
28. $promise->wait();