Stream Operations

When ever we operate on data we will have basic CURD operation. Let's see how we are doing CURD in streams:

1) Create a stream:

List<Integer> lstInt = Arrays.asList(1,2,3,4,5,6,7,8);

lstInt.stream().forEach(System.out::println);

Stream has 2 steps - Configuring and Processing

In configuring phase, we would apply non terminal operations - filters and mappings

In processing phase, operation applied and result is produced

List<Integer> lstInt = Arrays.asList(1,2,3,4,5,6,7,8);

lstInt.stream().filter( item -> item > 5 ).forEach(System.out::println);

filter() - non terminal operations

forEach() - terminal operations

2) Update a stream: Updation is not removing actual elements from stream but filtered and givin what is expected. Once terminal operation is specified we can't use them again

3) Read a stream: All terminal operation which prints out elements are read operation - forEach(), collect()

4) Delete stream: 

  removeIf uses an Iterator to iterate over the list and match the elements using the predicate.

  removeAll uses a simple for-loop to remove all the matching elements in the list.

Non-Terminal Operations:
filter()
map()
flatMap()
distinct()
limit()
peek()
Terminal Operations:
anyMatch()
allMatch()
noneMatch()
collect()
count()
findAny()
findFirst()
forEach()
min()
max()
reduce()
toArray()