安卓基础（Okhttp3）

1️⃣ 添加 OkHttp 依赖

📌 在 app/build.gradle 添加 OkHttp 依赖

dependencies {implementation 'com.squareup.okhttp3:okhttp:4.9.3'
}

2️⃣ 发送 GET 请求

📌 发送一个 GET 请求

实例化okhttp客户端--->创建请求--->发送请求

import okhttp3.*;import java.io.IOException;public class OkHttpExample {public static void main(String[] args) {// 1. 创建 OkHttpClient（网络客户端）OkHttpClient client = new OkHttpClient();// 2. 构造请求（GET 请求）Request request = new Request.Builder().url("https://jsonplaceholder.typicode.com/todos/1") // 目标 URL.build();// 3. 发送请求（异步执行）client.newCall(request).enqueue(new Callback() {@Overridepublic void onFailure(Call call, IOException e) {System.out.println("请求失败: " + e.getMessage()); // 请求失败}@Overridepublic void onResponse(Call call, Response response) throws IOException {String responseBody = response.body().string(); // 获取返回数据System.out.println("请求成功: " + responseBody); // 打印数据}});}
}

3️⃣ 发送 POST 请求

📌 使用 POST 发送 JSON 数据

实例化okhttp客户端--->创建json数据--->创建body（含有json数据）--->创建请求（含有body)--->发送请求

import okhttp3.*;
import org.json.JSONObject;import java.io.IOException;public class OkHttpPostExample {public static void main(String[] args) {OkHttpClient client = new OkHttpClient();// 1. 创建 JSON 数据JSONObject json = new JSONObject();json.put("title", "Hello OkHttp");json.put("body", "This is a test post");json.put("userId", 1);// 2. 创建 RequestBodyRequestBody requestBody = RequestBody.create(json.toString(),MediaType.parse("application/json; charset=utf-8"));// 3. 创建请求（POST 请求）Request request = new Request.Builder().url("https://jsonplaceholder.typicode.com/posts").post(requestBody).build();// 4. 发送请求（异步）client.newCall(request).enqueue(new Callback() {@Overridepublic void onFailure(Call call, IOException e) {System.out.println("请求失败: " + e.getMessage());}@Overridepublic void onResponse(Call call, Response response) throws IOException {String responseBody = response.body().string();System.out.println("请求成功: " + responseBody);}});}
}

📌 实现 WebSocket 客户端（连接、发送消息、接收消息、关闭）

import okhttp3.*;public class WebSocketExample {public static void main(String[] args) {// 1️⃣ 创建 OkHttpClientOkHttpClient client = new OkHttpClient();// 2️⃣ 创建 WebSocket 连接请求Request request = new Request.Builder().url("wss://echo.websocket.org") // WebSocket 服务器地址.build();// 3️⃣ 创建 WebSocket 监听器WebSocketListener listener = new WebSocketListener() {@Overridepublic void onOpen(WebSocket webSocket, Response response) {System.out.println("✅ WebSocket 连接成功");webSocket.send("Hello WebSocket!"); // 发送消息}@Overridepublic void onMessage(WebSocket webSocket, String text) {System.out.println("📩 收到消息: " + text);}@Overridepublic void onClosed(WebSocket webSocket, int code, String reason) {System.out.println("❌ WebSocket 连接关闭: " + reason);}@Overridepublic void onFailure(WebSocket webSocket, Throwable t, Response response) {System.out.println("⚠️ WebSocket 连接失败: " + t.getMessage());}};// 4️⃣ 创建 WebSocket 连接WebSocket webSocket = client.newWebSocket(request, listener);// 5️⃣ 关闭 WebSocket 客户端（防止程序未终止）client.dispatcher().executorService().shutdown();}
}