在Android中，可以使用HttpURLConnection或OkHttp库来发送POST和GET请求。

下面是使用HttpURLConnection发送POST和GET请求的代码示例：

1. 发送POST请求：

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

public class HttpPostExample {

    private final String USER_AGENT = "Mozilla/5.0";

    public static void main(String[] args) throws Exception {

        HttpPostExample http = new HttpPostExample();

        // 发送POST请求
        String url = "https://example.com/api";
        String postData = "param1=value1¶m2=value2";

        http.sendPost(url, postData);
    }

    // 发送POST请求
    private void sendPost(String url, String postData) throws Exception {

        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();

        // 添加请求头
        con.setRequestMethod("POST");
        con.setRequestProperty("User-Agent", USER_AGENT);
        con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

        // 发送POST数据
        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.writeBytes(postData);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();
        System.out.println("\n发送POST请求到URL：" + url);
        System.out.println("POST参数：" + postData);
        System.out.println("响应代码：" + responseCode);

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

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

        // 打印响应结果
        System.out.println("响应结果：" + response.toString());
    }
}

2. 发送GET请求：

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

public class HttpGetExample {

    private final String USER_AGENT = "Mozilla/5.0";

    public static void main(String[] args) throws Exception {

        HttpGetExample http = new HttpGetExample();

        // 发送GET请求
        String url = "https://example.com/api?param1=value1¶m2=value2";

        http.sendGet(url);
    }

    // 发送GET请求
    private void sendGet(String url) throws Exception {

        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();

        // 添加请求头
        con.setRequestMethod("GET");
        con.setRequestProperty("User-Agent", USER_AGENT);

        int responseCode = con.getResponseCode();
        System.out.println("\n发送GET请求到URL：" + url);
        System.out.println("响应代码：" + responseCode);

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

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

        // 打印响应结果
        System.out.println("响应结果：" + response.toString());
    }
}

这是使用HttpURLConnection发送POST和GET请求的简单示例。请注意，这是在Java中的示例代码，如果要在Android项目中使用，请将其放在适当的位置，并确保在AndroidManifest.xml文件中添加网络访问权限。

对于OkHttp库的使用，您可以参考OkHttp的官方文档，使用它发送POST和GET请求。