HTTP请求与响应：使用Java发送GET/POST请求-蒲公英云

HTTP请求与响应：使用Java发送GET/POST请求

原创男娘i 2024-09-12 09:00 151阅读 0赞

在Java中，我们可以使用各种库来发送HTTP GET或POST请求。这里我将展示如何使用Java的HttpURLConnection和OkHttp库进行操作。

HttpURLConnection (推荐旧版本)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class HttpURLConnectionExample {
    public static void main(String[] args) throws Exception {
        // 创建URL对象
        URL url = new URL("http://example.com/");
        // 创建HttpURLConnection连接
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        // 设置请求方法
        connection.setRequestMethod("GET"); // 或 POST
        // 如果是POST，需要设置请求参数
        if ("POST".equals(connection.getRequestMethod()))) {
            connection.setDoOutput(true);
            String data = "key1=value1&key2=value2"; // 需要替换为实际内容
            byte[] inputBytes = data.getBytes("UTF-8"); // 注意这里需要转换字符编码
            connection.getOutputStream().write(inputBytes);
        }
        // 获取响应状态码
        int responseCode = connection.getResponseCode();
        System.out.println("Response Code: " + responseCode);
        // 读取响应数据（如果是GET，不需要写这行）
        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()))); 
        String responseLine;
        while ((responseLine = reader.readLine()) != null)) {
            System.out.println(responseLine);
        }
        // 关闭连接
        connection.disconnect();
    }
}

OkHttp (推荐新版本)

import okhttp3.*;
public class OkHttpExample {
    public static void main(String[] args) throws Exception {
        // 创建OkHttpClient对象
        OkHttpClient client = new OkHttpClient();
        // 发送GET请求
        Request requestGet = new Request.Builder()
                .url("http://example.com/"))
                .build();
        Response responseGet = client.newCall(requestGet).execute();
        System.out.println("Response Get Code: " + responseGet.code());
        // 发送POST请求（这里假设数据以JSON格式发送）
        Request requestPostJson = new Request.Builder()
                .url("http://example.com/post/"))
                .post(new FormBody.Builder()
                        .add("key1", "value1")
                        .add("key2", "value2")
                        .build()))
                .build();
        Response responsePostJson = client.newCall(requestPostJson).execute();
        System.out.println("Response Post Json Code: " + responsePostJson.code());
        // 关闭OkHttpClient连接
        client.close();
    }
}