Apache HttpClient - Http Post 请求
POST 请求用于向服务器发送数据；例如，使用 HTML 表单发送客户信息、上传文件等。
HttpClient API 提供了一个名为 HttpPost 的类，该类表示 POST 请求。
按照以下步骤使用 HttpClient 库发送一个 HTTP POST 请求。
步骤 1 - 创建一个 HttpClient 对象
HttpClients 类的 createDefault() 方法返回 CloseableHttpClient 类的一个对象，该类是 HttpClient 类的基本实现。
使用此方法创建 HttpClient 对象。
CloseableHttpClient httpClient = HttpClients.createDefault();
步骤 2 - 创建 HttpPost 对象
HttpPost 类表示 HTTP POST 请求。此请求发送所需数据，并使用 URI 从给定的服务器获取信息。
通过实例化 HttpPost 类并向其构造函数传递一个表示 URI 的字符串值来创建此请求。
HttpGet httpGet = new HttpGet("https://tutorialspoint.com/");
步骤 3 - 执行 Get 请求
CloseableHttpClient 对象的 execute() 方法接受一个 HttpUriRequest（接口）对象（即 HttpGet、HttpPost、HttpPut、HttpHead 等），并返回一个响应对象。
HttpResponse httpResponse = httpclient.execute(httpget);
示例
以下是一个演示使用 HttpClient 库执行 HTTP POST 请求的示例。
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
public class HttpPostExample {
public static void main(String args[]) throws Exception{
//Creating a HttpClient object
CloseableHttpClient httpclient = HttpClients.createDefault();
//Creating a HttpGet object
HttpPost httppost = new HttpPost("https://tutorialspoint.com/");
//Printing the method used
System.out.println("Request Type: "+httppost.getMethod());
//Executing the Get request
HttpResponse httpresponse = httpclient.execute(httppost);
Scanner sc = new Scanner(httpresponse.getEntity().getContent());
//Printing the status line
System.out.println(httpresponse.getStatusLine());
while(sc.hasNext()) {
System.out.println(sc.nextLine());
}
}
}
输出
上面的程序将生成以下输出。
Request Type: POST <!DOCTYPE html> <!--[if IE 8]><html class = "ie ie8"> <![endif]--> <!--[if IE 9]><html class = "ie ie9"> <![endif]--> <!--[if gt IE 9]><!--> <html lang = "en-US"> <!--<![endif]--> <head> <!-- Basic --> <meta charset = "utf-8"> <title>Parallax Scrolling, Java Cryptography, YAML, Python Data Science, Java i18n, GitLab, TestRail, VersionOne, DBUtils, Common CLI, Seaborn, Ansible, LOLCODE, Current Affairs 2018, Apache Commons Collections</title> <meta name = "Description" content = "Parallax Scrolling, Java Cryptography, YAML, Python Data Science, Java i18n, GitLab, TestRail, VersionOne, DBUtils, Common CLI, Seaborn, Ansible, LOLCODE, Current Affairs 2018, Intellij Idea, Apache Commons Collections, Java 9, GSON, TestLink, Inter Process Communication (IPC), Logo, PySpark, Google Tag Manager, Free IFSC Code, SAP Workflow"/> <meta name = "Keywords" content="Python Data Science, Java i18n, GitLab, TestRail, VersionOne, DBUtils, Common CLI, Seaborn, Ansible, LOLCODE, Gson, TestLink, Inter Process Communication (IPC), Logo"/> <meta http-equiv = "X-UA-Compatible" content = "IE = edge"> <meta name = "viewport" conten t= "width = device-width,initial-scale = 1.0,userscalable = yes"> <link href = "https://cdn.muicss.com/mui-0.9.39/extra/mui-rem.min.css" rel = "stylesheet" type = "text/css" /> <link rel = "stylesheet" href = "/questions/css/home.css?v = 3" /> <script src = "/questions/js/jquery.min.js"></script> <script src = "/questions/js/fontawesome.js"></script> <script src = "https://cdn.muicss.com/mui-0.9.39/js/mui.min.js"></script> </head> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . </script> </body> </html>
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