import org.apache.commons.lang.StringUtils; public class Example { public static void main(String[] args) { String str = "Hello, World!"; String lowerStr = StringUtils.lowerCase(str); System.out.println(lowerStr); // Output: hello, world! } }In this example, we import the StringUtils class from the Apache Commons Lang library. We then create a new string variable `str` with the value "Hello, World!". We call the `lowerCase()` method on `str` using StringUtils and store the result in a new variable `lowerStr`. Finally, we print `lowerStr` to the console, which outputs "hello, world!". This method is useful when you need to compare two strings but you don't want to worry about case sensitivity. You can simply call `lowerCase()` on both strings before comparing them to ensure they are in the same case. To use the StringUtils class in your Java project, you will need to add the Apache Commons Lang library to your classpath. You can find more information on how to do this in the documentation for the library.