Execution Mode of a Stream – Oracle Certified Professional Java SE 17 Developer

Building Streams – Streams

07/23/2024Aspects of Streams, Revisited, Converting between Stream Types, Execution Mode of a Stream, Mapping between Numeric Streams, Oracle Exams, Selecting Distinct Elements Standard

16.4 Building Streams A stream must have a data source. In this section we will explore how streams can be created from various data sources: collections, arrays, specified values, generator functions, strings, and I/O channels, among others. Aspects to Consider When Creating Streams When creating a stream from a data source, certain aspects to consider […]

Summary of Intermediate Stream Operations – Streams

03/23/2024Execution Mode of a Stream, Oracle Exams Standard

Summary of Intermediate Stream Operations Table 16.3 summarizes selected aspects of the intermediate operations. Table 16.3 Selected Aspects of Intermediate Stream Operations Intermediate operation Stateful/Stateless Can change stream size Can change stream type Encounter order distinct (p. 915) Stateful Yes No Unchanged dropWhile (p. 913) Stateful Yes No Unchanged filter (p. 910) Stateless Yes No […]

Filtering – Streams

10/23/2023Aspects of Streams, Revisited, Execution Mode of a Stream, Oracle Exams Standard

Filtering Filters are stream operations that select elements based on some criteria, usually specified as a predicate. This section discusses different ways of filtering elements, selecting unique elements, skipping elements at the head of a stream, and truncating a stream. The following methods are defined in the Stream<T> interface, and analogous methods are also defined […]

Order of Intermediate Operations – Streams

05/23/2023Converting between Stream Types, Execution Mode of a Stream, Oracle Exams Standard

Order of Intermediate Operations The order of intermediate operations in a stream pipeline can impact the performance of a stream pipeline. If intermediate operations that reduce the size of the stream can be performed earlier in the pipeline, fewer elements need to be processed by the subsequent operations. Moving intermediate operations such as filter(), distinct(), […]

Setting a Stream as Unordered – Streams

01/23/2023Execution Mode of a Stream, Mapping between Numeric Streams, Oracle Exams Standard

Setting a Stream as Unordered The unordered() intermediate operation does not actually reorder the elements in the stream to make them unordered. It just removes the ordered constraint on a stream if this constraint is set for the stream, indicating that stream operations can choose to ignore its encounter order. Indicating the stream to be […]

Summary of Stream Building Methods – Streams

12/23/2022Execution Mode of a Stream, Oracle Exams, Selecting Distinct Elements Standard

Summary of Stream Building Methods Selected methods for building streams from various data sources are listed in Table 16.1. The first column lists the method names and the reference type that provides them. For brevity, the parameters of the methods are omitted. Note that some methods are overloaded. The prefix NumType stands for Int, Long, […]

Streams from Arrays – Streams

10/23/2022Aspects of Streams, Revisited, Converting between Stream Types, Execution Mode of a Stream, Mapping between Numeric Streams, Oracle Exams, Selecting Distinct Elements Standard

Streams from Arrays We have seen examples of creating streams from arrays when discussing the variable arity of() method of the stream interfaces and the overloaded Arrays.stream() methods earlier in the chapter (p. 893). The sequential stream created from an array has the same order as the positional order of the elements in the array. […]

Taking and Dropping Elements Using Predicates – Streams

08/23/2022Execution Mode of a Stream, Oracle Exams Standard

Taking and Dropping Elements Using Predicates Both the takeWhile() and the dropWhile() methods find the longest prefix of elements to take or drop from the input stream, respectively. The code below at (1) and (2) illustrates the case for ordered streams. The take-While() method takes odd numbers from the input stream until a number is […]

Mapping: Transforming Streams – Streams

03/23/2022Aspects of Streams, Revisited, Execution Mode of a Stream, Oracle Exams Standard

Mapping: Transforming Streams The map() operation has already been used in several examples (Example 16.3, p. 906, Example 16.4, p. 909, and Example 16.6, p. 920). Here we take a closer look at this essential intermediate operation for data processing using a stream. It maps one type of stream (Stream<T>) into another type of stream […]

Selecting Distinct Elements – Streams

09/23/2021Converting between Stream Types, Execution Mode of a Stream, Oracle Exams Standard

Selecting Distinct Elements The distinct() method removes all duplicates of an element from the input stream, resulting in an output stream with only unique elements. Since the distinct() method must be able to distinguish the elements from one another and keep track of them, the stream elements must override the equals() and the hashCode() methods […]

Category : Execution Mode of a Stream