Error Exception Hierarchy In Details in Java Updated

Error Hierarchy In Java

The Throwable class is the root class for every exception and it branches out to 2 main categories i.e.;

1. Exception
2. Error

Read Also: Rerun Failed test cases TestNG

java.lang.Throwable

• Throwable is the root class for exception & it’s sub-type and error & it’s sub-types
• In other words, it is a superclass for exception & error
• java.lang.The throwable class extends java.lang.Object class (as shown in the above figure)
• It defines 2 subclasses i.e.; Exception and Error

java.lang.Exception

• java.lang.Exception is a superclass for all types of Exception
• It extends java.lang.Throwable class
• The exception is due to programmatic logic
• And it is recoverable
• An exception are categorized into a checked and unchecked exception
• Example: RuntimeException, SQLException, IOException, FileNotFoundException, ArithmeticException, NullPointerException

Check: ClassCast Exception

java.lang.Error

• java.lang.Error is a superclass for all types of Error
• It extends java.lang.Throwable class
• Error is due to lack of system resources
• And it is non-recoverable
• All error falls into unchecked exception category, as it is raised due to lack of system resources at runtime
• It is out of programming scope as such type of error can’t predict, maybe well-planned care can be taken to avoid this kind of Error
• Example: VirtualMachineError, AssertionError, ExceptionInInitializerError, StackOverflowError, OutOfMemoryError, LinkageError, InstantiationError

Note: the above-mentioned Exception and Error are again categorized into checked and unchecked exceptions