functional interface java 8

TreeMap, similar to TreeSet, allows you to sort the elements in the collection while preserving the uniqueness of the elements.It should be noted that comparable (implement interface, remember to overwrite Comparato method), comparator use.1 ImportJava.util.Iterator;2 ImportJava.util.TreeMap;3 4 Importcn.itcast.p2.bean.Student;5 ImportCn.itcast.p3.comparator.ComparatorByName;6 7 Public classTreemapdemo {8

1 //There is also polymorphism between the interface and the specific implementation class2 Public classTestInterface {3 4 Public Static voidMain (string[] args) {5Duck d =NewDuck ();6 Testinterface.test1 (d);7 Testinterface.test2 (d);8 Testinterface.test3 (d);9 }Ten One Public Static voidTest1 (Runner R) {//Runner r = new Duck (); AR.run ();//virtual method Invocation - } -

ForEach methods of Streams and List Describe Stream interface and stream pipeline Filter a collection by using lambda expressions Use method references with Streams LAMBDA Built-in functional Interfaces Use the built-in interfaces included in the Java.util.function package such as predicate, Consumer, function, and Supplie R Develop code that uses primitive versions of

). Start (); String msg = "Hello"; runnable = (), {System.out.println (msg); System.out.println ("Run 1"); System.out.println ("Run 2"); }; New Thread (runnable). Start (); consumerpreviously, the parameters of methods in Java were mostly special anonymous class objects (there was only one abstract method in the interface-

determine if the class and object are of the same version. 5 * /6 public class person implements serializable/* tag interface */{7 /** 8 * Transient: Non-static data does not want to be serialized can use this keyword adornment. 9 */10 private static final long serialversionuid = 9527l;// private transient String name;12 p Rivate string name;13// private static int age;14

JAVA 8 Streams and javastreamsWhat is Stream? First, do not be fooled by its name. Here, Stream is different from InputStream and OutputStream in java I/O. Stream in Java 8 is actually the concept of Monad in functional programmin

First chapter lambda expressionsThe Lamada expression, the most important new feature in Java SE 8, has long been considered a missing feature in Java, and its appearance has made the entire Java language complete.At least for now, in this section you will learn what lambda is and why he is an excellent part. New techn

Tips"Effective Java, third Edition" an English version has been published, the second edition of this book presumably many people have read, known as one of the four major Java books, but the second edition of 2009 published, to now nearly 8 years, but with Java 6, 7, 8, and

The world is always a picture more than tens of thousands of words!The following 8 images are from the program Creek Java tutorial, which is currently the most popular article on the site.I hope this article will help you to review the knowledge you already know. If the picture is not clear enough, you may need to read a detailed article or search.1. Properties of the string object that cannot be changed(pl

Java transaction (8), java transaction I. Preface: In the previous blog, we used jotm to implement distributed transactions. This article uses atomikos. The basic code is the same, that is, the configuration is slightly different. Ii. Code implementation: 1. code structure: 2. configuration file: ApplicationContext. xml For other code, see the previous blog.

1. log4j– Most popular Java log componentsLog4j is a Java-based open source log component, log4j is very powerful, we can output log information to the console, file, user interface, can also output to the operating system's event logger and some system resident process. It is also worth mentioning that log4j allows you to customize the log format and log level v

Transferred from: http://www.codeceo.com/article/8-java-log-framework.htmlAs a Java programmer, we have developed many Java applications, including desktop applications, Web applications, and mobile applications. However, the log system is essential for a mature Java applica

1. log4j– Most popular Java log componentsLog4j is a Java-based open source log component, log4j is very powerful, we can output log information to the console, file, user interface, can also output to the operating system's event logger and some system resident process. It is also worth mentioning that log4j allows you to customize the log format and log level v

can be written Map Lambda expressions only show what we care about, parameters and return values. Due to type inference, you can save the parameter type. The specific syntax is not described here. You can find a lot of information online. Extra: If you have a good understanding of generics, The groupByKey method can be further abstracted: public static List} We have also extracted the Employee class, and the benefits are obvious. The Function inter