Operations

  • Intermediate operations
    • Stream.filter(): to filter all elements of the stream
    • Stream.map(): converts each element into another object via the given function
    • Stream.sorted(): returns a sorted view of the stream
  • Terminal operations
    • Stream.forEach(): iterating over all elements of a stream and perform some operation on each of them
    • Stream.collect(): receive elements from a stream and store them in a collection
    • Stream.match(): check whether a certain predicate matches the stream
    • Stream.count(): returning the number of elements in the stream as a long
    • Stream.reduce(): performs a reduction on the elements of the stream with the given function (like concat or merge two thing together)

Short-circuit operations

所謂短路操作，就是符合條件的運算後，就中斷操作，如同if-else一樣。

  • Stream.anyMatch()
  • Steam.findFirst()

Convert streams to collections

Please note that it is not a true conversation. It’s just collecting the elements from the stream into a collection or array.

請注意，這不是真正的轉換。它只是將流中的元素收集到集合或數組中。

  • Convert Stream to List: Stream.collect(Collections.toList())
  • Convert Stream to array: Stream.toArray(EntryType[]::new)

Reference