Built-in Exceptions in Java with examples

Types of Exceptions in Java Built-in exceptions are the exceptions that are available in Java libraries. These exceptions are suitable to explain certain error situations. Below is the list of important built-in exceptions in Java. 

Examples of Built-in Exception:

1. Arithmetic exception : It is thrown when an exceptional condition has occurred in an arithmetic operation. 

Can't divide a number by 0

2. ArrayIndexOutOfBounds Exception: It is thrown to indicate that an array has been accessed with an illegal index. The index is either negative or greater than or equal to the size of the array. 

Array Index is Out Of Bounds

3. ClassNotFoundException : This Exception is raised when we try to access a class whose definition is not found. 

Output:

ClassNotFoundException

4. FileNotFoundException : This Exception is raised when a file is not accessible or does not open. 

File does not exist

5. IOException : It is thrown when an input-output operation failed or interrupted 

Output:

error: unreported exception IOException; must be caught or declared to be thrown

6. InterruptedException : It is thrown when a thread is waiting, sleeping, or doing some processing, and it is interrupted. 

Output:

error: unreported exception InterruptedException; must be caught or declared to be thrown

7. NoSuchMethodException : t is thrown when accessing a method which is not found. 

Output:

error: exception NoSuchMethodException is never thrown 
in body of corresponding try statement

8. NullPointerException : This exception is raised when referring to the members of a null object. Null represents nothing 

Output:

NullPointerException..

9. NumberFormatException : This exception is raised when a method could not convert a string into a numeric format. 

Output:

Number format exception

10. StringIndexOutOfBoundsException : It is thrown by String class methods to indicate that an index is either negative than the size of the string. 

Output:

StringIndexOutOfBoundsException

Some other important Exceptions

1. ClassCastException

Output:

Exception in thread "main" java.lang.ClassCastException: 
java.lang.Object cannot be cast to java.lang.String

2. StackOverflowError

Output:

Exception in thread "main" java.lang.StackOverflowError

3. NoClassDefFoundError

Output:

Note: If the corresponding Test.class file is not found 
during compilation then we will get Run-time Exception
saying Exception in thread "main" java.lang.NoClassDefFoundError

4. ExceptionInInitializerError

Code 1: 

Output:

Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.ArithmeticException: / by zero

Code 2 : 

Output:

Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException

Explanation : The above exception occurs whenever while executing static variable assignment and static block if any Exception occurs.

5. IllegalArgumentException

Output:

Exception in thread "main" java.lang.IllegalArgumentException

Explanation:The Exception occurs explicitly either by the programmer or by API developer to indicate that a method has been invoked with Illegal Argument.

6. IllegalThreadStateException

Output:

Exception in thread "main" java.lang.IllegalThreadStateException

Explanation : The above exception rises explicitly either by programmer or by API developer to indicate that a method has been invoked at wrong time.

7. AssertionError

Output:

Exception in thread "main" java.lang.AssertionError

Explanation : The above exception rises explicitly by the programmer or by API developer to indicate that assert statement fails.

IllegalArgumentException: This exception is thrown when an illegal argument is passed to a method.

For example:

IllegalArgumentException occurred: Radius cannot be negative

FileNotFoundException: This exception is thrown when a file cannot be found.

For example: