Function Can constitute a stack of interceptors to complete specific functions, such as logging, login judgment, permission check and so on. Benefits Interceptors also allow you to modularize generic code as reusable classes. Applications of interceptors: AOP; needs some business logic (need to inject beans, etc.) Understand An interceptor acts Read more…
Introduction An Optional is a container object which may or may not contain a non-null value. It was introduced in Java 8 to cure the curse of NullPointerExceptions. In essence Optional is a wrapper class which contains a reference to some other object. In this context an object is just Read more…
foreach list.forEach(System.out::println); map List<Integer> numbers = Arrays.asList(3, 2, 2, 3, 7, 3, 5); List<Integer> squaresList = numbers.stream().map( i -> i*i).distinct().collect(Collectors.toList()); filter List<String>strings = Arrays.asList("abc", "", "bc", "efg", "abcd","", "jkl"); // count empty strings long count = strings.stream().filter(string -> string.isEmpty()).count(); List<UserInfo> list = new ArrayList<>(); UserInfo userInfo1 = new UserInfo(); userInfo1.setUserName("aa"); Read more…
Official Doc: https://docs.docker.com/engine/install/ubuntu/ Run the following command to uninstall all conflicting packages: for pkg in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do sudo apt-get remove $pkg; done Set up Docker’s apt repository. # Add Docker's official GPG key: sudo apt-get update sudo apt-get install ca-certificates curl sudo install -m Read more…