深入理解 HTTP 协议：从基础到实践全解析 - ToB企服应用市场:ToB评测及商务社交产业平台

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class HttpRequestExample {
public static void main(String[] args) {
// 发送 GET 请求
try {
URL url = new URL("https://www.example.com/api/data");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
System.out.println("GET Response Code :: " + responseCode);
if (responseCode == HttpURLConnection.HTTP_OK) {
BufferedReader in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine())!= null) {
response.append(inputLine);
}
in.close();
System.out.println("GET Response Body :: " + response.toString());
}
} catch (IOException e) {
e.printStackTrace();
}
// 发送 POST 请求
try {
URL url = new URL("https://www.example.com/api/create");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
String data = "key1=value1&key2=value2";
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
out.writeBytes(data);
out.flush();
out.close();
int responseCode = connection.getResponseCode();
System.out.println("POST Response Code :: " + responseCode);
if (responseCode == HttpURLConnection.HTTP_OK) {
BufferedReader in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String inputLine;
StringBuilder response = new StringBuilder();
while ((inputLine = in.readLine())!= null) {
response.append(inputLine);
}
in.close();
System.out.println("POST Response Body :: " + response.toString());
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

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GET /example HTTP/1.1
Host: www.example.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9

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HTTP/1.1 200 OK
Date: Tue, 20 Jul 2021 12:34:56 GMT
Server: Apache/2.4.46 (Win64) PHP/7.4.21
Content-Type: text/html; charset=UTF-8
Content-Length: 1234
<!DOCTYPE html>
<html>
<head>
<title>Example Page</title>
</head>
<body>
<h1>Hello, World!</h1>
</body>
</html>

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