您可以使用以下代码示例来实现在安卓应用程序中发送翻译成功消息的功能：

import android.os.AsyncTask;
import android.util.Log;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class TranslationTask extends AsyncTask {

    private static final String TAG = "TranslationTask";
    private static final String TRANSLATION_API_URL = "https://translation.googleapis.com/language/translate/v2?key=YOUR_API_KEY";

    @Override
    protected String doInBackground(String... params) {
        String sourceText = params[0];
        String targetLanguage = params[1];

        try {
            // 创建翻译请求的JSON对象
            JSONObject requestObj = new JSONObject();
            requestObj.put("q", sourceText);
            requestObj.put("target", targetLanguage);

            // 发送POST请求并获取翻译结果
            URL url = new URL(TRANSLATION_API_URL);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setRequestProperty("Content-Type", "application/json");

            OutputStream outputStream = conn.getOutputStream();
            outputStream.write(requestObj.toString().getBytes());
            outputStream.flush();
            outputStream.close();

            InputStream inputStream = conn.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuilder response = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            reader.close();
            inputStream.close();
            conn.disconnect();

            // 解析翻译结果JSON
            JSONObject responseObj = new JSONObject(response.toString());
            JSONArray translations = responseObj.getJSONArray("translations");
            JSONObject translationObj = translations.getJSONObject(0);
            return translationObj.getString("translatedText");

        } catch (IOException | JSONException e) {
            Log.e(TAG, "Translation error: " + e.getMessage());
            return null;
        }
    }

    @Override
    protected void onPostExecute(String translatedText) {
        // 在这里处理翻译成功后的操作，比如发送消息
        if (translatedText != null) {
            sendMessage(translatedText);
        }
    }

    private void sendMessage(String message) {
        // 在这里实现发送消息的逻辑
        Log.d(TAG, "Sending message: " + message);
        // TODO: 在这里添加发送消息的代码
    }
}

请注意，您需要替换YOUR_API_KEY为您自己的Google翻译API密钥。

要使用此代码示例，您可以在需要翻译文本的位置调用TranslationTask类的execute方法。例如：

String sourceText = "Hello!";
String targetLanguage = "zh-CN";
TranslationTask translationTask = new TranslationTask();
translationTask.execute(sourceText, targetLanguage);

在onPostExecute方法中，您可以在sendMessage方法中添加适合您应用程序的发送消息的代码。