无法从java程序运行curl命令

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

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

            // 打开连接
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            // 设置请求方法
            connection.setRequestMethod("GET");

            // 发送请求
            int responseCode = connection.getResponseCode();

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

            // 输出响应结果
            System.out.println("Response Code: " + responseCode);
            System.out.println("Response Body: " + response.toString());

            // 关闭连接
            connection.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}