java httputil

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

public class HttpUtil {

    // 发送GET请求
    public static String sendGet(String urlString) {
        StringBuilder result = new StringBuilder();
        try {
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");

            // 设置连接超时时间和读取超时时间
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(5000);

            // 获取响应码
            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String line;
                while ((line = reader.readLine()) != null) {
                    result.append(line);
                }
                reader.close();
            } else {
                System.out.println("GET request failed with response code: " + responseCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result.toString();
    }

    // 发送POST请求
    public static String sendPost(String urlString, String param) {
        StringBuilder result = new StringBuilder();
        try {
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setDoOutput(true); // 启用输出流

            // 设置请求头
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            // 设置连接超时时间和读取超时时间
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(5000);

            // 写入POST参数
            byte[] postData = param.getBytes("UTF-8");
            connection.getOutputStream().write(postData);

            // 获取响应码
            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String line;
                while ((line = reader.readLine()) != null) {
                    result.append(line);
                }
                reader.close();
            } else {
                System.out.println("POST request failed with response code: " + responseCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result.toString();
    }

    public static void main(String[] args) {
        // 示例：发送GET请求
        String getResponse = sendGet("http://example.com/api/get");
        System.out.println("GET Response: " + getResponse);

        // 示例：发送POST请求
        String postResponse = sendPost("http://example.com/api/post", "param1=value1&param2=value2");
        System.out.println("POST Response: " + postResponse);
    }
}

解释说明：

1. sendGet 方法：用于发送 HTTP GET 请求。它接收一个 URL 字符串作为参数，并返回服务器的响应内容。如果响应码为 200（HTTP_OK），则读取并返回响应内容；否则，打印错误信息。

2. sendPost 方法：用于发送 HTTP POST 请求。它接收一个 URL 字符串和一个参数字符串作为参数，并返回服务器的响应内容。设置请求头为 application/x-www-form-urlencoded，并将参数写入输出流。如果响应码为 200，则读取并返回响应内容；否则，打印错误信息。

3. main 方法：包含两个示例调用，分别演示如何使用 sendGet 和 sendPost 方法发送 HTTP 请求，并打印响应结果。

希望这段代码对你有帮助！