functional interface java 8

defined as follows: Package java.util; Public interface comparator Description1. If a class implements the comparator interface: it must implement the CompareTo (t O1, T O2) function, but it may not implement the Equals (Object obj) function.Why not implement the Equals (Object obj) function? Because any class, the default is already implemented equals (Object obj). All classes in

Java 8 Lambda, javalam.pdf Some new projects within the company adopt Java 8 one after another, so that we have the motivation to study Java 8's legendary big killer. The first improvement mentioned in the

New features in Java 8Java 8 (also known as JDK 1.8) is a major version of Java language development. Oracle Corporation released Java 8 on March 18, 2014, which supports functional programming, new JavaScript engines, new date AP

the collection class libraries, which are located under the Java.util.stream package and are not confused with the Java IO stream. From the above code you can see that the use of the Stream class library can basically be divided into the following steps: The conversion of the collection to flow, convection operation, the flow into the corresponding data structure. Get Stream Trace the stream () method of the above code in the IDE that supports viewin

[Java learning notes] The Map interface sub-interface --- TreeMap, learning notes --- treemap Similar to TreeSet, TreeMap can sort elements in a set and maintain the uniqueness of elements. It should be noted that Comparable (The implementation interface should overwrite the comparaTo method) is used by Comparator. 1

The 1:set collection consists of the implementation classes of the set interface and the set interface, and the set interface inherits the collection interface because it contains all the methods of the collection interface.2: Because duplicate values are not allowed in the

implement the comparable interface.//to implement a method that compares two class sizesSystem.out.println (list); //Random arrangementCollections.shuffle (list);//Shuffle (List); random arrangementSystem.out.println (list); //reverse arrangement (in reverse order)Collections.reverse (list);//void reverse (List); reverse order (linked more efficient)System.out.println (list); System.out.println ("-------------------------"); List List2=NewArrayList (

of Java concurrency programming, with over more than 20 years of experience in software consulting industry. Brian is the lead player in JSR 335, and his team of experts has made a significant contribution to the success of Java 8. Here are some wonderful answers to Brian's questions about Java

Track("Time Was", 541)); Track shortestTrack = tracks.stream().min(Comparator.comparing(track -> track.getLength())).get(); Returns the music with the minimum length.Reduce To generate a value from a group of values. The count, min, and max methods of Stream are actually reduce operations. Accumulate as follows: int sum = Stream.of(1, 2, 3).reduce(0, (acc, element) -> acc + element); Integrated Operation Next, let's look at another example. Suppose we can find out the nationality of all t

serialization of JAVA5.0, which is used to read objects 　　Serialization:Write the JAVA object. It is similar to persistence. 　Deserialization:Encapsulate read data into JAVA objects When you use Object stream to save an Object, you must implement the Serializable serialization interface in the class of the Object to be saved. However, if you do not want to seria

annotation: @FunctionalInterface , not required, is used to indicate that the interface is designed as a functional interface2.4 Use of Lambdapredicate filter out empty strings in the list// 定义一个函数式接口interface PredicateConsumer calculates the square of each element in the list and outputs@FunctionalInterfacepublic interface