Could not create connection to database server Android Studio

If you are an Android developer working with databases in Android Studio, you may encounter the error message "could not create connection to database server" or "Caused by: android.os.NetworkOnMainThreadException" at some point. This error can occur when you try to establish a connection between your Android Studio project and a database server, but the connection fails for some reason. In this article, we will explore some possible causes of this error and how to fix it.

Paste the following code in your 'OnCreate' method of the Activity.

Kotlin

val policy = StrictMode.ThreadPolicy.Builder().permitAll().build()
StrictMode.setThreadPolicy(policy)

Java

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

If this code does not solve your problem then read the following steps:

Incorrect Connection Settings

One of the most common causes of the "could not create connection to database server" error is incorrect connection settings. Make sure that you have entered the correct host name, port number, database name, username, and password for your database server. Double-check your settings to ensure that there are no typos or mistakes.

Network Connectivity Issues

Another possible cause of the error is network connectivity issues. Make sure that your computer is connected to the internet and that there are no issues with your network connection. Try pinging your database server to make sure that it is reachable.

Firewall Settings

Firewalls can sometimes block connections to your database server. Check your firewall settings to ensure that your firewall is not blocking the connection to your database server. You may need to add an exception to your firewall settings to allow connections to your database server.

Insufficient Permissions

If you are using a remote database server, make sure that you have sufficient permissions to access the database. Check with your database administrator to ensure that you have the necessary permissions.

Database Server Configuration

Your database server may not be configured correctly, which can prevent Android Studio from establishing a connection. Check your database server logs to see if there are any errors or issues that could be causing the connection problem.

JDBC Driver Issues

If you are using a JDBC driver to connect to your database server, try using a different driver to see if that resolves the issue. Make sure that the JDBC driver you are using is compatible with your database server and that it is installed correctly.

Android Studio Version Issues

Finally, the version of Android Studio that you are using may be causing the issue. Try updating to the latest version of Android Studio to see if that resolves the issue. If you are already using the latest version, try downgrading to a previous version to see if that resolves the issue.

If you encounter the "could not create connection to database server" error in Android Studio, it can be frustrating and time-consuming to diagnose and fix the issue. However, by following the steps outlined in this article, you can troubleshoot the problem and identify the root cause. Whether the issue is with your connection settings, network connectivity, firewall settings, permissions, database server configuration, JDBC driver, or Android Studio version, there is always a solution. By being patient and methodical in your approach, you can overcome the error and continue building your Android app with confidence.

What is android.os.NetworkOnMainThreadException

The android.os.NetworkOnMainThreadException is a runtime exception that occurs when you attempt to perform a network operation on the main thread in an Android application. The main thread is responsible for handling user interface events and should not be blocked by long-running tasks such as network operations, which can cause the app to become unresponsive.

The android.os.NetworkOnMainThreadException error can be fixed by moving the network operation to a separate thread or using an asynchronous network library. By following the steps outlined in this article, you can ensure that your app remains responsive and doesn't crash due to this error.