java发送post请求带参数

好的，下面是Java发送POST请求带参数的示例代码：

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

public class HttpPostExample {
    public static void main(String[] args) throws Exception {
        String url = "http://example.com/api";
        String name = "John";
        int age = 30;
        String data = "name=" + URLEncoder.encode(name, "UTF-8") + "&age=" + age;

        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();
        con.setRequestMethod("POST");
        con.setDoOutput(true);

        OutputStream os = con.getOutputStream();
        os.write(data.getBytes());
        os.flush();
        os.close();

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

        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

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

        System.out.println("Response : " + response.toString());
    }
}

这段代码会向指定的URL发送一个POST请求，请求的参数是name和age，然后把服务器返回的响应打印出来。其中，name需要使用URLEncoder.encode()方法进行编码，以避免URL中的特殊字符引起问题。