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This article introduces the difference and efficiency between Iterator and Enumeration Iterator is an interface. Its source code is as follows: package java.util; import java.util.function.Consumer; public interface Iterator<E> { //Returns the reference of the element that the iterator just crossed. The return value is Obje ...

Brief Introduction As a Java programmer, HashMap is an inevitable data type.This is evidenced by both the frequency of use in development and the frequency of inspection in interviews. HashMap's Past and Present HashMap was born in JDK1.2. With the update of JDK version and to solve hash collision problem in HashMap in JDK1.7,Oracle team at JE ...

Sharing graph of wechat friend circle in pure Java 1. Realize the effect of sharing chart 2. Development environment 2.1 JDK *oracle's JDK above 1.8 2.2 font *If you choose Microsoft YaHei font and the code is deployed to Linux, you need to install Microsoft YaHei font, and google the font installation mode 3. Loading background 3.1 loading ba ...

Project brief introduction Data-Factory It is used to generate initialization information randomly and automatically according to the object, which avoids the tedious of creating the object manually and is easy to test. Characteristic 8 basic types of support String, Date, amount, Date and other common types of support Java 8 common time class ...

I. The Origin of tomcat Name origin: tomcat was originally developed by sun's software architect James Duncan Davidson. Later he helped turn it into an open source project, which Sun contributed to the Apache Software Foundation. Because O'Reilly, the majority of open source projects, will produce a related book and design its cover as a sketc ...

Preface: Environmental Science: windown 10 Eclipse JDK 1.8 Concept of RPC: RPC is a remote procedure call and the basis of distributed web site. Experiment SayHelloService.java interface class for specification SayHelloServiceImpl.java is the implementation class of SayHelloService Provider.java is the service providing class C ...

I. what is it? Why? Serialization is the process of transforming the state information of an object into a form that can be stored or transmitted, and deserialization is its reverse process. Memory volatility; transmission needs; some application scenarios need to persist objects for reading when needed. II. API provided by JDK writeObject( ...

Build a jar package Using Spring Boot to build a simple web program, you can start it directly using java jar. @RestController @RequestMapping("/root") @SpringBootApplication public class SbDemoApplication { public static void main(String[] args) { SpringApplication.run(SbDemoApplication.class, args); } @RequestMapping("/h ...

Sketch The Linux system used in this article is Ubuntu 16.04 and JDK is 1.8.0_. JDK Download JDK 1.8.0? Download link: https://pan.baidu.com/s/1AgiZ5DHnJjCVxBKPzdCddw Extraction code: v1ud Linux installing Java Create a folder in / usr/local / directory and upload the downloaded JDK through Xftp tool (if there is no Xftp ...

Spring has only available on JDK 1.5 and higher error detailed solution!!! Summary: Summary: Previously, when learning Spring, there was a problem incompatible with the jdk version, and an error will be reported at runtime: Caused by: java.lang.IllegalStateException: Context namespace element 'component-scan' and its parse ...