To import all of the classes in the Java libraries, you can use the * wildcard character. For example, to import all of the classes in the java.util package, you can use the following import statement:
import java.util.*;
This will import all of the classes in the java.util package, allowing you to use them in your code without having to specify the full package name every time.
It's worth noting that importing all of the classes in the Java libraries may not always be the best approach, as it can lead to longer compile times and may make it more difficult to identify which classes are being used in your code. In general, it's a good idea to import only the classes that you need, rather than importing all of the classes in a package.
To import a specific class from a package, you can use the following syntax:
import java.util.ArrayList;
This will import only the ArrayList class from the java.util package, allowing you to use it in your code without specifying the full package name.