Question

我正在尝试将我的Android设备连接到MySQL服务器上运行的MySQL数据库。但我不断收到下面所述的错误。

有谁能请我指出正确的方向？

logcat的

07-15 09:17:21.708: E/AndroidRuntime(19677): FATAL EXCEPTION: AsyncTask #1
07-15 09:17:21.708: E/AndroidRuntime(19677): java.lang.RuntimeException: An error occured while executing doInBackground()
07-15 09:17:21.708: E/AndroidRuntime(19677):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.FutureTask.run(FutureTask.java:239)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.lang.Thread.run(Thread.java:841)
07-15 09:17:21.708: E/AndroidRuntime(19677): Caused by: java.lang.VerifyError: net/sourceforge/jtds/jdbc/TdsCore
07-15 09:17:21.708: E/AndroidRuntime(19677):    at net.sourceforge.jtds.jdbc.JtdsConnection.<init>(JtdsConnection.java:359)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:184)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.sql.DriverManager.getConnection(DriverManager.java:179)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.sql.DriverManager.getConnection(DriverManager.java:213)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at com.example.rf.MainActivity.runSQL(MainActivity.java:110)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at com.example.rf.MainActivity$DoInBackground.doInBackground(MainActivity.java:58)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at com.example.rf.MainActivity$DoInBackground.doInBackground(MainActivity.java:1)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
07-15 09:17:21.708: E/AndroidRuntime(19677):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
07-15 09:17:21.708: E/AndroidRuntime(19677):    ... 4 more

CODE

我如何称呼它：

new DoInBackground().execute();

方法：

private class DoInBackground extends AsyncTask<Void, Void, Void>   
{
    @Override
    protected Void doInBackground(Void...unused) {
        String response = "";
        try {
            runSQL();
        }
        catch(Exception e) {
            Log.i("Error", e.toString());           
        }
        return null;   
    }
}

public void runSQL()
{
    String connectionString = "jdbc:jtds:sqlserver://server:1433/DBNAME;instance=SQLEXPRESS";
    String userName = "username";
    String password = "password";
    try {
        Class.forName("net.sourceforge.jtds.jdbc.Driver"); //specify the jtds driver

        Connection conn = DriverManager.getConnection(connectionString, userName, password); //establish connection
        //System.out.println("Connection properly established");
        Log.i("Success", "Connected to DB");
        conn.close();
    } catch (Exception e)
    {
        String err = (e.getMessage()==null)?"SD Card failed":e.getMessage();
        Log.e("sdcard-err2:",err);  
    }
}

更新

我发现了这个问题。问题是，我使用ktds 1.3.1作为连接到数据库的驱动程序，但这个版本被窃听。因此切换回1.3.0版本解决了我的问题。

感谢您的帮助！

Answer 1

我假设您正在尝试从Android客户端连接服务器的SQL。您无法从Android客户端直接连接到SQL服务器。您需要在服务器端为它创建Web服务。

如果服务器是JAVA，那么您可以使用REST with Java (JAX-RS) using Jersey。
在Android方面，您可以使用this simple RestClient来处理该REST服务。
对于JSON＆lt; - ＆gt;双方的对象映射（Android，Java后端）可以使用GSON。

在Web服务中，您可以使用适当的JDBC连接..

致命异常：AsyncTask＃1？

1 个答案: