Introduction to the detailed function of the HTTP client framework in the Java class library

The HTTP client framework in the Java class library provides many functions, allowing developers to easily send HTTP requests and processing responses.Below is a detailed introduction to several common functions of the HTTP client framework. 1. Send GET and Post requests: The HTTP client framework can help developers send Get and Post requests.Developers can specify information such as URL, request method, request header, request body, etc., and can add interceptors before or after sending requests.The following is an example code that uses Apache httpclient to send GET and Post requests: // Create HTTPCLIENT object CloseableHttpClient httpClient = HttpClients.createDefault(); // Create HTTPGET request HttpGet httpGet = new HttpGet("http://example.com/api/data"); // Send a GET request and get a response CloseableHttpResponse response = httpClient.execute(httpGet); // Printing response content System.out.println(EntityUtils.toString(response.getEntity())); // Close httpclient and response response.close(); httpClient.close(); // Create httppost requests HttpPost httpPost = new HttpPost("http://example.com/api/data"); // Set the request body StringEntity requestEntity = new StringEntity("{\"key\":\"value\"}"); httpPost.setEntity(requestEntity); // Send the post request and get a response CloseableHttpResponse response = httpClient.execute(httpPost); // Printing response content System.out.println(EntityUtils.toString(response.getEntity())); // Close httpclient and response response.close(); httpClient.close(); 2. Set the request header and request body: The HTTP client framework allows developers to set the custom request head and request body.This is very useful for sending a required required header or a request body.The following is a sample code for setting the request head and the request body: // Create httppost requests HttpPost httpPost = new HttpPost("http://example.com/api/data"); // Set the request header httpPost.setHeader("Content-Type", "application/json"); // Set the request body StringEntity requestEntity = new StringEntity("{\"key\":\"value\"}"); httpPost.setEntity(requestEntity); 3. Support HTTPS: HTTP client framework provides support for HTTPS.Developers can easily send HTTPS requests and verify the server's certificate in the request.Here are examples of sending HTTPS requests with Apache httpClient: // Create HTTPCLIENT object CloseableHttpClient httpClient = HttpClients.createDefault(); // Create HTTPGET request HttpGet httpGet = new HttpGet("https://example.com/api/data"); // Create SSL context SSLContext sslContext = SSLContexts.custom().loadTrustMaterial(null, new TrustSelfSignedStrategy()).build(); // Create SSL connection factory SSLConnectionSocketFactory sslSocketFactory = new SSLConnectionSocketFactory(sslContext); // Create httpclientbuilder and set up SSL connection factories HttpClientBuilder builder = HttpClients.custom().setSSLSocketFactory(sslSocketFactory); // Use httpclientbuilder to create an HTTPClient object CloseableHttpClient httpClient = builder.build(); // Send HTTPS request and get a response CloseableHttpResponse response = httpClient.execute(httpGet); // Printing response content System.out.println(EntityUtils.toString(response.getEntity())); // Close httpclient and response response.close(); httpClient.close(); 4. Processing response: The HTTP client framework provides many methods to handle HTTP response.Developers can obtain information such as the status code, response header, and response body of the response, and can analyze and process the response content as needed.The following is a sample code for handling HTTP response: // Send a request and get a response CloseableHttpResponse response = httpClient.execute(httpGet); // Get the response status code int statusCode = response.getStatusLine().getStatusCode(); // Get the response header Header[] headers = response.getAllHeaders(); for (Header header : headers) { System.out.println(header.getName() + ": " + header.getValue()); } // Get the response body String responseBody = EntityUtils.toString(response.getEntity()); // Close the response response.close(); These functions of the HTTP client framework simplify the process of processing the HTTP request and response of developers, and provide many flexibility and scalability, so that developers can interact more easily with Web services.