Java 8 is a giant step forward for the Java language. Writing this book has forced me to learn a lot more about it. In Project Lambda, Java gets a new closure syntax, method-references, and default methods on interfaces. It manages to add many of the features of functional languages wit...
<R> Stream<R>flatMap(Function<?superT, ? extends Stream<? extends R>> mapper); 显然,跟map()方法不同的是,Function函数的返回值类型是Stream<? extends R>类型,而不是R类型,即Function函数返回一个Stream流,这样flatMap()能够将一个二维的集合映射成一个一维的集合,比map()方法拥有更高的映射深度(此...
There are a couple in the Map interface as well. You should check a good Java book like Java 8 in Action to find out more about such important methods. That's all about what is default methods in Java 8, Why default or defender methods were added in Java programming language, and how...
The definition of stream in Java 8 is “a sequence of elements from a source that supports aggregate operations.†Streams consume from a source such as collections, arrays, or I/O resources. Streams support the common operations from functional programing languages, such as map,...
Chapter 8, BDD – Working Together with the Whole Team, discusses developing a book store application by using the BDD approach. We'll define the acceptance criteria in the BDD format, carry out the implementation of each feature separately, confirm that it is working correctly by running BDD ...
核心内容:用JAVA 8 提供的Optional来替换null,其中解决最多就是 Null Pointer Exception的问题 使用范围建议: 1、当使用Optional时,就不用考虑对象是否存在或合理默认值。而且随时调用get()方法。 2、如果没有合理默认值,使用map()和 .flatMap()方法,等后面再对对象赋值。
Java provides an inbuilt solution for our problem. So, what's the wait? Let's start! What is Blocking Deque in Java? BlockingDeque is a deque that is thread-safe. Multiple threads can work on the same data structure without any error or exception. But, a BlockingDeque has a lock on th...
what 's different between rxjava .flatmap { } kotlin 's also { } apply { } ? what 's different between rxjava .flatmap { } kotlin 's also { } apply { } ?
Avoiding time consuming logic when using flatmapIterable I have a task to split a word into characters and then transfer each to another word. I write some test code, use toCharArray to get char array in the flatMapIterable section, but if the target string... ...
When asked to compare Scala to Groovy and JRuby, Odersky said that Scala is about as complicated as JDK 7 and will be less complicated than JDK 8. He feels Groovy is more complicated because it is a superset of Java. This is an interestingly different perspective on complexity. I have fou...