Java HttpRequest.post带参数例子

在Java中，如果你想要使用`HttpURLConnection`或第三方库如Apache HttpClient发送POST请求并携带参数，你可以按照以下步骤操作：

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

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "http://example.com/api";
        String requestBody = "key1=value1&key2=value2"; // 这里替换为你实际的参数字符串

        try (BufferedReader reader = new BufferedReader(new StringReader(requestBody))) {
            URL obj = new URL(url);
            HttpURLConnection con = (HttpURLConnection) obj.openConnection();

            // 设置连接属性
            con.setRequestMethod("POST");
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // 表示我们发送的是表单数据
            con.setDoOutput(true); // 指定我们要写入输出流

            // 发送数据
            byte[] data = requestBody.getBytes(); // 转换参数为字节数组
            con.getOutputStream().write(data);

            // 获取响应
            int responseCode = con.getResponseCode();
            System.out.println("Response Code : " + responseCode);

            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader in = new BufferedReader(
                        new InputStreamReader(con.getInputStream()));
                String inputLine;
                StringBuffer response = new StringBuffer();

                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }
                in.close();

                // 打印结果
                System.out.println(response.toString());
            } else {
                throw new RuntimeException("Failed : HTTP error code : " + responseCode);
            }
        }
    }
}