What is Validate.notNaN() in Java?

notNaN() is a staticthe methods in Java that can be called without creating an object of the class. method of the Validate class that is used to check that the specified double value is not NaN. If the specified value is NaN, the method throws an exception. Otherwise, it does not return anything.

How to import Validate

The definition of Validate can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file:

<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the Validate class as follows.

import org.apache.commons.lang3.Validate;

Syntax

public static void notNaN(final double value, final String message, final Object... values)

Parameters

• final double value: The double value to check.

• final String message: The exception message.

• final Object... values: The optional values for the formatted exception message.

Return value

This method does not return anything.

Code

Output

The output of the code will be as follows:

Exception in thread "main" java.lang.IllegalArgumentException: Argument should not be NaN
	at org.apache.commons.lang3.Validate.notNaN(Validate.java:907)
	at Main.main(Main.java:13)

Example 1

• double value = 234322343

The method does not throw an exception, as the input value is not NaN.

Example 2

• double value = Double.NaN

The method throws an IllegalArgumentException exception, as the input value is NaN.