连接的应用程序到SQL Server数据库

Question

我想我的应用程序连接到SQL Server数据库

我创造了这个loginActivity：

import android.annotation.SuppressLint; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.StrictMode; 
import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ProgressBar; 
import android.widget.Toast; 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 



public class LoginActivity extends AppCompatActivity 
{ 
    // Declaring layout button, edit texts 
    Button login; 
    EditText username,password; 
    ProgressBar progressBar; 
    // End Declaring layout button, edit texts 

    // Declaring connection variables 
    Connection con; 
    String un,pass,db,ip; 
    //End Declaring connection variables 

    @Override 
    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_login); 

     // Getting values from button, texts and progress bar 
     login = (Button) findViewById(R.id.btnlogin); 
     username = (EditText) findViewById(R.id.txtStagiaireName); 
     password = (EditText) findViewById(R.id.txtStagiairePass); 
     progressBar = (ProgressBar) findViewById(R.id.progressBar); 
     // End Getting values from button, texts and progress bar 

     // Declaring Server ip, username, database name and password 
     ip = "192.168.1.9:1433"; 
     db = "dbcom"; 
     un = "sa"; 
     pass = "123456"; 
     //End Declaring Server ip, username, database name and password 

     // Setting up the function when button login is clicked 
     login.setOnClickListener(new View.OnClickListener() 
     { 
      @Override 
      public void onClick(View v) 
      { 
       CheckLogin checkLogin = new CheckLogin();// this is the Asynctask, which is used to process in background to reduce load on app process 
       checkLogin.execute(""); 
      } 
     }); 
     //End Setting up the function when button login is clicked 
    } 

    public class CheckLogin extends AsyncTask<String,String,String> 
    { 
     String z = ""; 
     Boolean isSuccess = false; 

     @Override 
     protected void onPreExecute() 
     { 
      progressBar.setVisibility(View.VISIBLE); 
     } 

     @Override 
     protected void onPostExecute(String r) 
     { 
      progressBar.setVisibility(View.GONE); 
      Toast.makeText(LoginActivity.this, r, Toast.LENGTH_SHORT).show(); 
      if(isSuccess) 
      { 
       Toast.makeText(LoginActivity.this , "Login Successfull" , Toast.LENGTH_LONG).show(); 
       //finish(); 
      } 
     } 
     @Override 
     protected String doInBackground(String... params) 
     { 
      String usernam = username.getText().toString(); 
      String passwordd = password.getText().toString(); 
      if(usernam.trim().equals("")|| passwordd.trim().equals("")) 
       z = "Please enter Username and Password"; 
      else 
      { 
       try 
       { 
        con = connectionclass(un, pass, db, ip);  // Connect to database 
        if (con == null) 
        { 
         z = "Check Your Internet Access!"; 
        } 
        else 
        { 
         // Change below query according to your own database. 
         String query = "select * from Stagiaire where username= '" + usernam.toString() + "' and password = '"+ passwordd.toString() +"' "; 
         Statement stmt = con.createStatement(); 
         ResultSet rs = stmt.executeQuery(query); 
         if(rs.next()) 
         { 
          z = "Login successful"; 
          isSuccess=true; 
          con.close(); 
         } 
         else 
         { 
          z = "Invalid Credentials!"; 
          isSuccess = false; 
         } 
        } 
       } 
       catch (Exception ex) 
       { 
        isSuccess = false; 
        z = ex.getMessage(); 
       } 
      } 
      return z; 
     } 
    } 


    @SuppressLint("NewApi") 
    public Connection connectionclass(String user, String password, String database, String server) 
    { 
     StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
     StrictMode.setThreadPolicy(policy); 
     Connection connection = null; 
     String ConnectionURL = null; 
     try 
     { 
      Class.forName("net.sourceforge.jtds.jdbc.Driver"); 
      ConnectionURL = "jdbc:jtds:sqlserver://" + server +";databaseName="+ database + ";user=" + user+ ";password=" + password + ";"; 
      connection = DriverManager.getConnection(ConnectionURL); 
     } 
     catch (SQLException se) 
     { 
      Log.e("error here 1 : ", se.getMessage()); 
     } 
     catch (ClassNotFoundException e) 
     { 
      Log.e("error here 2 : ", e.getMessage()); 
     } 
     catch (Exception e) 
     { 
      Log.e("error here 3 : ", e.getMessage()); 
     } 
     return connection; 
    } 
} 

当我编译该项目，并把用户名和密码，总是我得到这个吐司：检查您的互联网访问！ 这意味着connectionURL = null。
但是为什么？如果我的代码有任何问题，请通知我！

12-02 22:43:23.116 2388-2388/com.reddivx.ismo.advancedismo I/art: Not late-enabling -Xcheck:jni (already on) 
12-02 22:43:23.116 2388-2388/com.reddivx.ismo.advancedismo W/art: Unexpected CPU variant for X86 using defaults: x86 
12-02 22:43:23.300 2388-2388/com.reddivx.ismo.advancedismo W/System: ClassLoader referenced unknown path: /data/app/com.reddivx.ismo.advancedismo-2/lib/x86 
12-02 22:43:23.314 2388-2388/com.reddivx.ismo.advancedismo I/InstantRun: starting instant run server: is main process 
12-02 22:43:23.394 2388-2388/com.reddivx.ismo.advancedismo W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable 
12-02 22:43:24.630 2388-2388/com.reddivx.ismo.advancedismo W/gralloc_ranchu: Gralloc pipe failed 

                      [ 12-02 22:43:24.632 2388: 2388 D/   ] 
                      HostConnection::get() New Host Connection established 0x9ae3d7c0, tid 2388 
12-02 22:43:24.674 2388-2409/com.reddivx.ismo.advancedismo I/OpenGLRenderer: Initialized EGL, version 1.4 
12-02 22:43:24.674 2388-2409/com.reddivx.ismo.advancedismo D/OpenGLRenderer: Swap behavior 1 
12-02 22:45:19.093 2388-2388/com.reddivx.ismo.advancedismo W/IInputConnectionWrapper: finishComposingText on inactive InputConnection 
12-02 22:46:44.606 2388-2968/com.reddivx.ismo.advancedismo E/error here 1 :: Network error IOException: Connection refused 

Answer 1

我不相信你可以在开箱即用的Android上使用JDBC。 请参考this SO question

还要检查this library，如果你想使用JDBC在Android