core java volume 2

, you only need to write the enumerated values without enumeration type./Enumeration/src/yuki/core/enumeration/switch_case/QuarkTest. java copy code package yuki. core. enumeration. switch_case; public class QuarkTest {public static void main (String [] args) {Quark quark = Quark. c; String name = null; switch (quark) {case U: name = "upper quark"; break; case D:

x mod/% n = x (n-1), therefore uses the bitwise and the operation instead of the modulo operation)This means that the array subscript is the same and does not indicate that the hashcode is the same.5) Table Initial Size public HashMap(int initialCapacity, float loadFactor) { ..... // Find a power of 2 >= initialCapacity int capacity = 1; while (capacity Note that the table initial size is not initialcapacity!! in the con

I. Introduction of the ContentJava EE's 13 core technologies: JDBC, JNDI, EJB, RMI, JSP, Java Servlet, XML, JMS, Java IDL, JTS, JTA, JavaMail, and JAF.Java was initially in the browser and client machines, when many questioned whether it was suitable for server-side development. Now with the increase in support for third-party

, in the programming language, threading can be a love-hate paradox for programmers, which can greatly simplify the model, help programmers write powerful code, and, on the other hand, make our programs appear with a variety of bugs that can be difficult to reproduce in the development environment. Here the author based on the "Java Core technology" book and some Bovinlai to share with you on

Fifth Chapter Succession1. Class Superclass sub-classInheritance: Extends (all inheritance sick a public inheritance, no private inheritance and protection inheritance)c+++: By:2. Using super (C # using base) to call the base class methodThe subclass constructor defaults to calling the base class's parameterless construct to initialize the private domain of the base classIf the base class does not have a parameterless construct, an error will be3.this

Java operating mechanism the JVM of the core mechanism The JVM is the runtime environment for Java programs The JVM is part of the JRE, it is a fictitious computer, or it can be understood that the bytecode file is interpreted as a machine instruction on a specific platform when the byte code file is executed by the CPU JVM with the byte code as the machine in

[Java Study Notes] Chapter 5 inheritance of Java core technologiesChapter 2 Inheritance Using inheritance, You can construct a new class based on an existing class. Inheriting existing classes is to reuse (inherit) the methods and domains of these classes. You can also add new methods and domains. Reflection.5.1 superc

Tags: Java running term runtime dump bin sudo tuning traceDump is a dump of information on the memory of the program runtime, allowing us to see how the program is running. Dump is a very useful tool for tuning and troubleshooting.Heap DumpThe Java runtime objects are allocated to heap memory, and heap dump is a dump of heap memory.GeneratedThere are two ways to build Heap dump: 1) Add an option when runnin

"Original" https://www.toutiao.com/i6594587397101453827/Java Core Data structure (List,map,set) usage tips and optimizationsJDK provides a set of major data structure implementations, such as list, MAP, set and other common data structures. This data is inherited from the Java.util.Collection interface and is located in the Java.util package. 1. List interface The three most important list interface impleme

Recently I read core Java, but I have never understood it before. I have read many posts and blogs and finally understood it. In Java, the char [], String, stringbuilder and stringbuffer class adopts UTF-16 encoding, using U + 0000 ~ U + FFFF represents a basic character (BMP character), but Char located in U + d800 to U + dbff and U + dc00 to U + dfff is conside

Collection interfaceFirst, Introduction:interface and implementation separation, use queue exampleProvide interface specificationInterface Queue{...}Specific implementationClass linkedlistqueueClass circulararrayqueuequeueSecond, iterators1. The basic interface of the collection class is collection, which consists of two basic methods:public interface Collection{Boolean Add (E element);Iterator...}public interface iterator{E next ();Boolean hasnext ();void Remove ();}From Javase 5.0, you can use

Core Java Questions and Answers (1-33), answers1-33Preface Http://www.journaldev.com/2366/core-java-interview-questions-and-answers.What are the important features of Java 8? Java 8 was released in March 2014, which is very common

, is hard to believe that people who don't know anything about the JVM can eat the Java language very well. When I interviewed developers with more than 3 years of Java experience, the JVM was almost a must-ask question. Of course, the JVM is not the only one to determine the technical ability of the interview problem, but can support Java development capabilitie

Java -- JDK dynamic proxy core source code parsing, java -- jdk source code 1. First, let's take a look at how to use JDK dynamic Proxy: Public static void main (String [] args) {/*** creates a Bean object that implements the BeanInterFace interface */BeanInterFace bean = new Bean (); /*** create a MyProxy object that implements the InvocationHandler interface an

. Cannot instantiate a type variable, cannot construct a generic arrayCannot be new T (...), new t[] or t.class, because when the type is erased, T becomes the object typeor Object[2],new object () is not what we want to see, you can use reflection to create an objectFirst. T.class is not legal.public static {try{return new Pair}catch (Exception ex){return null}}Pair6. Invalid type variable in static context of generic classCannot reference a type var

j2ee| detailed Java was originally staged in browsers and client machines. At the time, many people questioned whether it was suitable for server-side development. Now, with the increase in Third-party support for the JAVA2 platform Enterprise version, Java is widely accepted as one of the preferred platforms for developing enterprise server-side solutions. The Java