With Java-11 and above, you can make use of the String.strip API to return a string whose value is this string, with all leading and trailing whitespace removed. The javadoc for the same reads :
/**
 * Returns a string whose value is this string, with all leading
 * and trailing {@link Character#isWhitespace(int) white space}
 * removed.
 * <p>
 * If this {@code String} object represents an empty string,
 * or if all code points in this string are
 * {@link Character#isWhitespace(int) white space}, then an empty string
 * is returned.
 * <p>
 * Otherwise, returns a substring of this string beginning with the first
 * code point that is not a {@link Character#isWhitespace(int) white space}
 * up to and including the last code point that is not a
 * {@link Character#isWhitespace(int) white space}.
 * <p>
 * This method may be used to strip
 * {@link Character#isWhitespace(int) white space} from
 * the beginning and end of a string.
 *
 * @return  a string whose value is this string, with all leading
 *          and trailing white space removed
 *
 * @see Character#isWhitespace(int)
 *
 * @since 11
 */
public String strip()
The sample cases for these could be:--
System.out.println("  leading".strip()); // prints "leading"
System.out.println("trailing  ".strip()); // prints "trailing"
System.out.println("  keep this  ".strip()); // prints "keep this"