Understanding the Difference Between Throws and Throwable in Java

Posted by: admin September 19, 2023 No Comments
Understanding the Difference Between Throws and Throwable in Java

When it comes to handling exceptions in Java, the terms “throws” and “Throwable” are commonly used, but they can be confusing for beginners. In this blog, we will explain the difference between throws and throwable and their uses.

Throws:

The “throws” keyword is used in Java to indicate that a method may throw a particular exception. It is followed by the name of the exception, and it is used in the method signature. This keyword is useful for notifying the caller of the method that the method may throw an exception, so the caller can take appropriate action to handle it. If a method is declared with the “throws” keyword, the caller of that method is required to handle the exception or propagate it further up the call stack.

For example, consider the following method:

CSharp

public void readFile() throws IOException {
// code to read a file
}

In this case, the method “readFile” may throw an IOException. If another method calls this method, it will either need to handle the exception or declare it with “throws IOException”.

Throwable:

On the other hand, “Throwable” is a superclass of all exceptions and errors in Java. It is the root of the exception hierarchy, and it provides two subclasses: “Exception” and “Error”. All exceptions and errors in Java extend from either “Exception” or “Error”, which in turn extend from “Throwable”.

When a method is declared with “throws Throwable”, it means that it can potentially throw any type of exception or error. This is not recommended, as it makes the code less predictable and harder to maintain.

Also read: Test automation solution for a Desktop App built on WPF platform with Java SWT controls

Uses:

The “throws” keyword is commonly used in method declarations to indicate the exceptions that the method may throw. It is useful for documenting the behavior of the method and for informing the caller of the potential exceptions.

On the other hand, the “Throwable” class is rarely used in Java programming. It is generally not recommended to catch or throw “Throwable”, as it includes both exceptions and errors and catching or throwing errors can be dangerous.

Conclusion:

In summary, the “throws” keyword is used to indicate the exceptions that a method may throw, while “Throwable” is a superclass of all exceptions and errors in Java. The former is useful for documenting the behavior of the method, while the latter is rarely used in Java programming. It is important to use these terms correctly to ensure that the code is predictable and maintainable.

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