Android出租车预订App存储阿拉伯文到SQL Server显示问号求助

Hey there! Let’s work through this Arabic text display issue—this is a common pain point with multi-language apps, so we’ll break it down step by step to find where things are going wrong.

First, let’s start with the SQL Server side, since you mentioned adjusting the encoding there already:

• Column Data Type is Critical: This is the #1 cause of question marks for non-Latin scripts. Make sure every column storing Arabic text uses nvarchar or nchar instead of varchar/char. varchar relies on single-byte encoding which can’t support Arabic characters—even with the right collation, you’ll get garbage or question marks. If your columns are currently varchar, alter them to nvarchar (e.g., ALTER TABLE YourTable ALTER COLUMN YourColumn NVARCHAR(255)).
• Verify Collation Settings: While you mentioned setting utf-8 general_ci, SQL Server uses its own collation system. Ensure your database and tables use a collation that supports Arabic, like Arabic_CI_AS or Arabic_CS_AS. You can check this with these queries:

  -- Check database collation
  SELECT name, collation_name FROM sys.databases WHERE name = 'YourDatabaseName';
  -- Check table collation
  SELECT name, collation_name FROM sys.tables WHERE name = 'YourTableName';
  

• Connection String Unicode Support: When your app connects to SQL Server, the connection string must explicitly enable Unicode. For JDBC connections, add useUnicode=true&characterEncoding=UTF-8 to your URL. Example:

  String dbUrl = "jdbc:sqlserver://your-server-ip:1433;databaseName=your-db;useUnicode=true;characterEncoding=UTF-8;user=your-username;password=your-password";
  

Next, let’s rule out issues on the Android Java side:

• Request Encoding: When sending Arabic text to the server, ensure your HTTP requests use UTF-8 encoding.
  • If using OkHttp, specify the media type with UTF-8 when building the request body:

    MediaType mediaType = MediaType.parse("application/json; charset=utf-8");
    RequestBody body = RequestBody.create(mediaType, yourArabicJsonString);
    

  • If using Retrofit, confirm your converter (like Gson) is set to use UTF-8. You can explicitly configure Gson like this:

    Gson gson = new GsonBuilder()
        .setCharset(StandardCharsets.UTF_8)
        .create();
    Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(GsonConverterFactory.create(gson))
        .build();
    

• Response Parsing: When receiving data back, make sure you’re reading the response with UTF-8. For HttpURLConnection, set the accept charset and read the input stream correctly:

  connection.setRequestProperty("Accept-Charset", "UTF-8");
  BufferedReader reader = new BufferedReader(
      new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8)
  );
  

• UI Font Support: Even if the data is correct, your app’s UI might not render Arabic if the font doesn’t support it. Use a font that includes Arabic glyphs, like Android’s built-in Noto Sans Arabic, or add a custom font to your project.

• Test Directly in SQL Server: Use SSMS to insert a sample Arabic string (e.g., INSERT INTO YourTable (ArabicColumn) VALUES (N'مرحبا')—note the N prefix for Unicode strings). If it displays correctly here, the problem is in your app’s data transfer/parsing. If it shows question marks, focus on fixing SQL Server’s setup.
• Log the Data: Add logs in your Android app to check the string before sending and after receiving:

  Log.d("ArabicDebug", "Sending Arabic text: " + arabicText);
  // After receiving
  Log.d("ArabicDebug", "Received Arabic text: " + receivedArabicText);
  

  If the sent log shows correct Arabic but the received log shows question marks, the issue is on the server or transfer. If the received log is correct but the UI shows question marks, it’s a font/display issue.

Most of the time, this boils down to using varchar instead of nvarchar in SQL Server, or missing the Unicode parameters in the connection string. Let me know if any of these steps help, or if you need more details!

内容的提问来源于stack exchange，提问作者hameed86