Socket 发送HTTP请求示例（原始）
1.创建socket ，同时建立连接： Socket socket = new Socket(host, port);
2.获取socket的InputStream，并写入请求行、请求头、请求体 ；
3.获取socket的OutputStream,获取到相应行、相应头、相应体 ；
4.关闭资源
import java.io.*;
import java.net.Socket;
public class SocketExample {
public static void main(String[] args) {
String host = "example.com";
int port = 80;
String path = "/abc";
String httpPostData = "key1=value1&key2=value2";
try {
// 建立套接字连接
Socket socket = new Socket(host, port);
String httpPostRequest = "POST http://" + host + path + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Content-Type: application/x-www-form-urlencoded\r\n" +
"Content-Length: " + httpPostData.length() + "\r\n" +
"\r\n" +
httpPostData;
// 发送 HTTP POST 请求
OutputStream out = socket.getOutputStream();
out.write(httpPostRequest.getBytes());
out.flush();
// 创建输入流，读取服务器响应
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
// 关闭流和套接字连接
in.close();
out.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}如下，请求内容
POST http://example.com/abc HTTP/1.1
Host: example.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 23
key1=value1&key2=value2
如下，响应内容
HTTP/1.0 400 Bad Request
Content-Type: text/html
Content-Length: 349
Connection: close
Date: Thu, 23 Nov 2023 02:36:15 GMT
Server: ECSF (sed/58EA)
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>400 - Bad Request</title>
</head>
<body>
<h1>400 - Bad Request</h1>
</body>
</html>
URL.openConnection()示例
1.创建URL对象
2.打开一个connection连接
3.设置请求方法，GET
4.发送请求，获取请求码和状态
5.获取请求体
6.连接关闭
public class HttpClientExample {
public static void main(String[] args) {
String urlString = "http://example.com/";
try {
// 创建 URL 对象
URL url = new URL(urlString);
// 打开 HTTP 连接
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
// 设置请求方法为 GET
connection.setRequestMethod("GET");
// 发送请求并获取响应状态码
int responseCode = connection.getResponseCode();
System.out.println("Response Code: " + responseCode);
//获取请求状态
String message = connection.getResponseMessage() ;
System.out.printf("message "+message+"\n");
// 读取响应内容
BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
StringBuilder response = new StringBuilder();
while ((line = in.readLine()) != null) {
response.append(line);
}
in.close();
// 打印响应内容
System.out.println("Response:");
System.out.println(response.toString());
// 关闭连接
connection.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}
}小结：
上面内容也是建立连接，发送请求行，请求头，请求体；服务器回应响应行，相应头，响应体