Sure, I can explain that.
In Java, you can use the trim() method of the String class to remove leading and trailing whitespaces from a string. Here's an example:
String input = " Hello, World! ";
String trimmed = input.trim();
System.out.println(trimmed);
Output:
Hello, World!
In this example, we first declare a String variable input and assign it a string with leading and trailing whitespaces. We then use the trim() method to remove the leading and trailing whitespaces, and assign the result to another String variable called trimmed. Finally, we print out the trimmed string.
Note that the trim() method only removes whitespace characters from the beginning and end of a string. Any whitespace characters in the middle of the string are left intact. If you want to remove all whitespace characters from a string, you can use the replaceAll() method with a regular expression, like this:
String input = " Hello, World! ";
String trimmed = input.replaceAll("\\s+", "");
System.out.println(trimmed);
Output:
Hello,World!
In this example, we use the replaceAll() method with the regular expression \\s+, which matches one or more whitespace characters. We replace all matches with an empty string to remove all whitespace characters from the string.