var http = (HttpWebRequest)WebRequest.Create(url);用java怎么写

在Java中，你可以使用`HttpURLConnection`类来发送HTTP请求。下面是将C#中的代码转换为Java的示例：

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) {
        String url = "http://example.com";

        try {
            URL urlObj = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) urlObj.openConnection();
            connection.setRequestMethod("GET");

            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String line;
                StringBuilder response = new StringBuilder();

                while ((line = reader.readLine()) != null) {
                    response.append(line);
                }
                reader.close();

                System.out.println(response.toString());
            } else {
                System.out.println("HTTP request failed. Response Code: " + responseCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

上述代码会发送一个GET请求到指定的URL，并打印出服务器的响应内容。你可以根据自己的需要进行适当的修改和扩展。