HttpURLConnection - OkHttp + Kotlin

HttpURLConnection → OkHttp + Kotlin

老写法（Java + HttpURLConnection）

new Thread(() -> {
    HttpURLConnection connection = null;
    try {
        URL url = new URL("https://api.example.com/data");
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.setConnectTimeout(10000);
        connection.setReadTimeout(10000);        int code = connection.getResponseCode();
        if (code == 200) {
            InputStream is = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            final String result = sb.toString();            runOnUiThread(() -> updateUI(result));
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (connection != null) connection.disconnect();
    }
}).start();

问题在哪里

手写 Socket 级别的连接管理、超时、流读取，代码量爆炸。线程切换全靠手动 new Thread + runOnUiThread。请求重试、缓存、HTTPS 证书校验全要自己实现，没有拦截器机制。

新写法（OkHttp + Coroutines）

添加依赖：

implementation "com.squareup.okhttp3:okhttp:4.12.0"

private val client = OkHttpClient.Builder()
        .connectTimeout(10, TimeUnit.SECONDS)
        .readTimeout(10, TimeUnit.SECONDS)
        .build()viewModelScope.launch(Dispatchers.IO) {
    val request = Request.Builder()
            .url("https://api.example.com/data")
            .get()
            .build()    try {
        val response = client.newCall(request).execute()
        if (response.isSuccessful) {
            val result = response.body?.string() ?: ""
            withContext(Dispatchers.Main) {
                updateUI(result)
            }
        }
    } catch (e: IOException) {
        withContext(Dispatchers.Main) {
            showError(e.message)
        }
    }
}

一句话注意

OkHttp 的 execute() 是同步方法，需要在后台线程调用。enqueue() 是异步回调，但用了协程就尽量用 execute() + 协程管理，避免回调嵌套。

response.body?.string() 只能调用一次，第二次返回空。如果需要反复读，先存到变量里。OkHttp 内部有自己的连接池和线程池，创建一次以单例使用即可，不要每次都 new。

Java Android 老项目迁移系列，持续更新中。