我无法从我的安卓手机连接到MySQL服务器数据库，而我可以从安卓工作室模拟器

Question

我正在使用带有在线SQL服务器数据库的android登录应用程序，我必须从任何平台访问它。我打开了 1433 端口并使用我的 IP 地址连接，并在 SQL Server 中完成了所有配置，但仍然无法从我的手机连接，而我可以轻松地从 android 工作室连接。

请帮助我，也许我错过了一些小东西。

主要活动.java

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.edtuserid);
edtpass = (EditText) findViewById(R.id.edtpass);
btnlogin = (Button) findViewById(R.id.btnlogin);
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) {
Intent i = new Intent(MainActivity.this, attendance.class);
startActivity(i);
finish();
}
}
@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 The server";
} else {
String query = "select * from tablename where id='" + userid + "' and Password='" + password + "'";
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";
}
}
return z;
}
}
}

连接类.java

public class ConnectionClass {
String ip = "192.168.....etc";
String classs = "net.sourceforge.jtds.jdbc.Driver";
String db = "dbname";
String un = "sql server login username";
String password = "*****";
@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);
ConnURL = "jdbc:jtds:sqlserver://" + ip + ";"
+ "databaseName=" + db + ";user=" + un + ";password="
+ password + ";";
conn = DriverManager.getConnection(ConnURL);
} catch (SQLException se) {
Log.e("ERRO", se.getMessage());
} catch (ClassNotFoundException e) {
Log.e("ERRO", e.getMessage());
} catch (Exception e) {
Log.e("ERRO", e.getMessage());
}
return conn;
}
}

清单

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>

Answer 1

数据库可以是本地数据库，但您必须配置网络，以便可以从外部访问它。

首先，如果您想在本地服务器上拥有数据库，则必须确保从ISP获得固定IP，或使用其他方式来确保即使IP更改，您的IP始终可访问(no-ip等可以为您执行此操作(。

其次，您必须将端口从路由器转发到数据库服务器，因此当它获得连接时，它将重定向到您的数据库服务器。

我的建议是将其放在托管服务中