
If you are working with Database in your app using ORM or Spring JDBC/Spring Boot JPA, you may get this exception,
Exception:Exception in thread "main" org.springframework.jdbc.CannotGetJdbcConnectionException:
Failed to obtain JDBC Connection; nested exception is com.mysql.cj.jdbc.exceptions.CommunicationsException:
Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago.
The driver has not received any packets from the server.
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
Fix/Solutions:
- Make sure your Database is up. Check connection to the database via DB Client or Console. Try doing telnet.
- How you defined the right database Hostname/IP Address in your JDBC DriverManager Connection URL?
- Have you defined the right Database server Port?
- Make sure your firewall settings are not restricting access.
- Make sure you have Internet connectivity.
- Make sure the Database server if having an IP Whitelisting policy, your IP is listed.
- If the Database Server is on Cloud (AWS/Azure/GCS), the right policies are set.
- If Database is on Docker Container, make sure the host port is exposed and accesiible
Have Questions? Post them here!
- Create a Zip file using Java Code programmatically
- Eclipse : A java Runtime Environment (JRE) or Java Development kit (JDK) must be available
- How to Sort a LinkedList in Java
- Loading class com.mysql.jdbc.Driver. This is deprecated. The new driver class is com.mysql.cj.jdbc.Driver
- How to declare and initialize Array in Java Programming
- [Fix] java: integer number too large compilation error
- Java JDBC Connection with MySQL Driver in VS Code + Troubleshooting
- Reading .xls and .xlsx Excel file using Apache POI Java Library
- IntelliJ: Error: Could not find or load main class, java.lang.ClassNotFoundException
- How to get Client IP address using Java Code Example
- Truncate table using Java JDBC Example
- Struts 2 : There is no Action mapped for namespace [/] and action name [form] associated with context path [/proj]
- How to get file path in Idea IntelliJ IDE
- Java Generics explained with simple definition and examples
- Java SE 8 Update 301 available with various bug fixes and security improvements
- Java: Collect Stream as ArrayList or LinkedList
- Java JDBC Connection with PostgreSQL Driver Example
- How to check if Java main thread is alive
- How to fix Java nio NoSuchFileException wile reading a file
- Java 8+ get Day of the Week Examples with LocalDateTime, DateTime, ZonalDateTime and Instant classes
- Ways to Convert Integer or int to Long in Java
- [Java] How to throws Exception using Functional Interface and Lambda code
- [Fix] Spring Boot: mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
- Java: The value of the local variable string is not used
- Java JDBC: Insert Java 8 LocalDate and Time using PreparedStatement
- Change Android EditText Cursor Height - Android
- How to clear MySQL Console Screen - MySQL
- [Eclipse] Enable or Disable print margin line - Eclipse
- [Fix] Docker Run unknown shorthand flag: 'r' in -rm - Docker
- Remove AirDrop Icon from macOS Menu Bar - MacOS
- Failed to sync Gradle project Error:failed to find target android-23 - Android
- How to Word-Warp Console logs in IntelliJ - Java
- Check help on commands while being on sftp> prompt - FTP