Finally, will execute even when we do not handle exceptions. You can create your own exception and give implementation as to how it should behave. Exception Handling in Java with Method Overriding is an overridden method that declares to throw an exception and declare that it can throw the same exception or subtype of that exception.
To handle the exception in Java, you will have to follow three important rules. They are depicted in the below figure. This brings us to the end of this article on exception handling in java. We hope that you are now clear about the concept of exception handling in java. If you wish to know more about the java programming language, then log on to our free java programming course and power ahead in your career. Remember Me! Great Learning is an ed-tech company that offers impactful and industry-relevant programs in high-growth areas.
Know More. Sign in. Log into your account. Forgot your password? Password recovery. This type of exception occurs when you try to access an object with the help of a reference variable whose current value is null or empty. This type of exception occurs when you try to access an array with an invalid index value. The value you are providing is either negative or beyond the length of the array. This type of exception occurs whenever an inappropriate or incorrect argument is passed to a method.
For example, if a method is defined with non-empty string as parameters. But you are providing null input strings. Then, the IllegalArgumentException is thrown to indicate the user that you cannot pass a null input string to the method. This type of exception occurs when the state of the environment does not match the operation being executed. For example, consider the following code snippet, which demonstrates this type of exception:. If a publication date already exists in the system, then it will produce an IllegalStateException that indicates that the book cannot be published again.
This type of exception occurs when you pass a string to a method that cannot be converted to a number. This type of exception occurs when you perform an incorrect arithmetic operation.
For example, if you divide any number by zero, it will display such an exception. Let us consider the following code snippet:.
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Start Free Trial. Figure 1: Types of Exceptions in Java. For example, If an application reads data from a file it should be able to handle the FileNotFoundException.
After all, there is no guarantee that the expected file is going to be where it is supposed to be. Anything could happen on the file system, which an application would have no clue about. To take this example one step further. Let's say we are using the FileReader class to read a character file. If you have a look at the FileReader constructor definition in the Java api you will see it's method signature:.
This makes sense as it's highly likely that the fileName String will be wrong from time to time. Look at the following code:. Syntactically the statements are correct but this code will never compile. The compiler knows the FileReader constructor can throw a FileNotFoundException and it's up to the calling code to handle this exception.
There are two choices - firstly we can pass the exception on from our method by specifying a throws clause too:. Or we can actually handle with the exception:. Well-written Java applications should be able to cope with checked exceptions.
The second kind of exception is known as the error. When an exception occurs the JVM will create an exception object. These objects all derive from the Throwable class. The Throwable class has two main subclasses— Error and Exception. The Error class denotes an exception that an application is not likely to be able to deal with.
These exceptions are considered rare. For example, the JVM might run out of resources due to the hardware not being able to cope with all the processes it is having to deal with.
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