java ANDROID数据库网络错误IOException

Question

你好，我是安卓的初学者。我想在我的电脑上建立到mssql服务器的数据库连接。我在网上找到了一个例子。 我想我的ip连接或端口有问题。我猜语法是错的。 我得到这个日志：

Network error IOException: failed to connect to /127.0.0.1 (port 1433) from /:: (port 55062): connect failed: ECONNREFUSED (Connection refused)

import 安卓.annotation.SuppressLint;
import 安卓.os.StrictMode;
import 安卓.util.Log;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnectionClass {
String ip = "127.0.0.1:1433";
String classs = "net.sourceforge.jtds.jdbc.Driver";
String db = "DBAndroid1";
String un = "TestUser";
String password = "123";

这是我的主要活动。爪哇

public class MainActivity extends AppCompatActivity {

ConnectionClass connectionClass;
EditText edtuserid, edtpass;
Button btnlogin;
ProgressBar pbbar;

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

    connectionClass = new ConnectionClass();
    edtuserid = (EditText) findViewById(R.id.et_username);
    edtpass = (EditText) findViewById(R.id.et_password);
    btnlogin = (Button) findViewById(R.id.btn_Login);
    pbbar = (ProgressBar) findViewById(R.id.pbbar);
    pbbar.setVisibility(View.GONE);

    btnlogin.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            DoLogin  doLogin = new DoLogin();
            doLogin.execute("");

        }
    });

}


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


    String userid = edtuserid.getText().toString();
    String password = edtpass.getText().toString();


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

    @Override
    protected void onPostExecute(String r) {
        pbbar.setVisibility(View.GONE);
        Toast.makeText(MainActivity.this,r,Toast.LENGTH_SHORT).show();

        if(isSuccess) {
            Toast.makeText(MainActivity.this,r,Toast.LENGTH_SHORT).show();
        }

    }

    @Override
    protected String doInBackground(String... params) {
        if(userid.trim().equals("")|| password.trim().equals(""))
            z = "Please enter User Id and Password";
        else
        {
            try {
                Connection con = connectionClass.CONN();
                if (con == null) {
                    z = "Error in connection with SQL server";
                } else {
                    String query = "select password from User";
                    Statement stmt = con.createStatement();
                    ResultSet rs = stmt.executeQuery(query);

                    if(rs.next())
                    {

                        z = "Login successfull";
                        isSuccess=true;
                    }
                    else
                    {
                        z = "Invalid Credentials";
                        isSuccess = false;
                    }

                }
            }
            catch (Exception ex)
            {
                isSuccess = false;
                z = "Exceptions burda mi ";
            }
        }
        return z;
    }
}
}



@SuppressLint("NewApi")
public Connection CONN() {
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
            .permitAll().build();
    StrictMode.setThreadPolicy(policy);
    Connection conn = null;
    String ConnURL = null;
    try {

        Class.forName(classs).newInstance();
        ConnURL = "jdbc:jtds:sqlserver://" + ip + ";"
                + "databaseName=" + db + ";user=" + un + ";password="
                + password + ";";
        conn = DriverManager.getConnection(ConnURL);
    } catch (SQLException se) {
        Log.e("ERRO0", se.getMessage());
    } catch (ClassNotFoundException e) {
        Log.e("ERRO1", e.getMessage());
    } catch (Exception e) {
        Log.e("ERRO2", e.getMessage());
    }
    return conn;
}
}

我希望你能帮忙。多谢各位

Answer 1

您是在模拟器上还是在设备上执行此操作？在您的设备上，确保您使用的是wi-fi，而不是手机数据。它需要在同一个网络上。您的IP应该是10.0.2.2，而不是localhost（aka 127.0.0.1），因为Android emulator位于VM上。仿真器的本地主机是指仿真器本身，而不是实际的本地主机