java post请求

Java中发送POST请求的代码示例：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class PostExample {
    public static void main(String[] args) {
        try {
            // 创建URL对象
            URL url = new URL("http://example.com/resource");

            // 创建HttpURLConnection对象
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

            // 设置请求方法为POST
            conn.setRequestMethod("POST");

            // 设置请求头
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            // 设置请求参数
            String params = "param1=" + URLEncoder.encode("value1", "UTF-8") +
                            "&param2=" + URLEncoder.encode("value2", "UTF-8");
            conn.setDoOutput(true);
            conn.getOutputStream().write(params.getBytes("UTF-8"));

            // 发送请求
            conn.connect();

            // 读取响应
            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            StringBuilder response = new StringBuilder();
            while ((line = in.readLine()) != null) {
                response.append(line);
            }
            in.close();

            System.out.println(response.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

其中，`url`是请求的地址，`params`是请求参数，`Content-Type`是请求头，可以根据实际情况进行修改。