Common Java Errors and How to Fix Them
Browse all documented Java errors with detailed explanations, root causes, and step-by-step fixes.
ORA-12545: TNS:Cannot register with TSLS (TNS Listener Service)
This error occurs when the Oracle JDBC driver is unable to establish a connection with the TNS Listener Service due to a…
Error executing SQL query: Cannot insert explicit value for identity column in t
This error occurs when you're trying to insert a value into an auto-incrementing primary key column in a database, but t…
Cannot get JDBC connection; nested exception is com.mysql.cj.jdbc.exceptions.Com
This error occurs when the Java application is unable to establish a connection to the database. It usually happens due …
Cannot find symbol: 'config' in class 'com.example.ConfigReader' on line 15
This error occurs when Java cannot find a declared class or method. In this case, it's because the class 'ConfigReader' …
java.lang.StackOverflowError at com.example.Main.main(Main.java:15) - unable to
This error occurs when a method calls itself recursively without a proper base case, leading to excessive recursion and …
Could not initialize Bean Validation provider for the constraint annotation: jav
This error occurs when the Bean Validation provider is not properly registered in the application. Bean Validation is us…
SQL syntax error or missing database driver exception: Unknown column 'email' in
This error occurs when the Java application is unable to find a column in the database table that matches the one specif…
java: cannot find symbol variable 'user' in method 'main' at line 10
This error occurs when the compiler cannot find the definition of a variable, method, or class that is being used in the…
Failed to autowire. No bean of type 'com.example.service.UserService' available.
This error occurs when the Spring Framework is unable to autowire a bean (a managed object) of the specified type. This …
java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.Threa
This error occurs when a task is submitted to an executor service that is shutting down or has been terminated.…
java.lang.StackOverflowError at java.base/java.util.concurrent.ConcurrentHashMap
This error occurs when a program exceeds the maximum stack size, typically due to infinite recursion or excessive method…
Cannot find symbol: variable 'name' in void main(String[] args)
This error occurs when the Java compiler is unable to find a declared variable or method. In this case, the variable 'na…
Have a Java error that's not listed? Get an instant explanation.
Explain Another Error