singleton class in java example

Java compressed file tool class ZipUtil usage code example, tool class ziputil This example uses the Java Zip input/output stream to compress and decompress files. The first part of the code is used to obtain the file path and cha

======= subclasses are instantiated by default when the parent class is empty, the constructor is super (), which can be omitted.However, when the parent class does not have an empty construction method, it must call this method in the subclass to instantiate the parent class before the instance class is real.The defau

1 Packagetimers;2 3 ImportJava.util.Timer;4 ImportJava.util.TimerTask;5 6 /*7 * Mainly want to use the object of this class in another class, how to use it? How to pass the same instance object8 */9 Public classTimerdemo {Ten Public Static voidMain (string[] args) { OneTimer T =NewTimer (); AT.schedule (NewMyTask (t), 3000); - } - } the - classMyTaskextendsTimerTask { //In order to use the T o

(intv) One { A synchronized(mysynchronized.class) - { - while(true) the { - System.out.println (v); - } - } + } - + Public voidRun () A { at Printval (val); - } -}View CodeAdditional Lock Examples:1 Public classMysynchronizedextendsThread2 {3 PrivateString name;4 5 PrivateString Val;6 7 Publicmysynchronized (string name, String v)8 {9 This. Name =name;Tenval =v; One } A

Gson This Java class library converts Java objects to JSON or converts JSON strings into an equal Java object. Gson supports arbitrary complex Java objects including objects that have no source code.Other JSON parsing libraries and Json-lib;jackson;com.alibaba.fastjson.Small

It is not recommended to use Singleton1 and Singleton2,singleton3 basic to meet the requirements, SINGLETON5 support delay loading, but the implementation of a bit of trouble, effective Java authors recommend the enumeration to implement a single case, automatic support serialization mechanism , preventing deserialization from recreating new objects, and absolutely preventing multiple instantiations implementing a single

We know that a Java application cannot access the private method of a persisted class, but Hibernate does not have this restriction to access various levels of methods, such as private, default, protected, public. How does hibernate implement this function? The answer is to use the Java reflection mechanism as follows: Import java.lang.reflect.InvocationTarg

Learn Java friends should know that Java from the beginning of the platform to play a non-independent banner, said "write once, run everywhere", actually speaking of irrelevant, the Java platform has another irrelevant that is language-independent, to achieve the language of independence, Then the Java System

Public voidg () { - y.f (); - } - } - - classTest008subextendsEGG2 { in Publictest008sub () { -System.out.println ("AA"); toInsertyolk (Newyolk ()); + } - the Public classYolkextendsEgg2.yolk { * Publicyolk () { $System.out.println ("Bigegg2.yolk ()");Panax Notoginseng } - the Public voidf () { +System.out.println ("Bigegg2.yolk.f ()"); A } the } + } - $ //order of calls in complex cases $ Public classTest008 { - Public Stat

Package jsckson;/******************************************** * File name: threadLocal An example of a Java inner class

JAVA Inner class One, what is the internal class? The definition of a class is placed inside another class, and this class is called an inner class What are the characteristics of th

class reference to the subclass instance of new, so what happens to the interface?Example 3: Anonymous class implementation interfaceFirst define an interface public interface Human {public void eat ();p ublic void Drink ();}public class Unnamedclass {public static void main (string[] args) { As you can

A simple example shows the relationship between java packet class and variables. javapacket 1. PACKET is a folder, and the CLASS in the package accesses each other as a file. 2. The class is equivalent to a DELPHI calss. static functions can only access static functions.

introduced dynamic proxies and was often used to dynamically create proxies. The dynamic proxy for the JDK is very simple to use, but it has a limitation that objects that use dynamic proxies must implement one or more interfaces. If you want to broker an inherited class that does not implement an interface, you need to use the Cglib package.3) The Cglib is implemented by ASM, ASM is a Java bytecode manipu

Echarts Java wrapper class Library: Http://www.oschina.net/p/echarts-java Did not expect to like Echarts Java Encapsulation Class Library of people quite a lot, in the source code test example general purpose is to construct the s

Java class set _ example: many-to-many relationship notes Instance requirements: One student can select multiple courses and multiple students can participate in one course. This is a typical multi-to-many relationship.To complete this program, we should first define two categories: Student for student information and course for course information. There is a col

interfaceEquivalent to an implementation class object that defines the interface and overrides all the abstract methods in the interfaceSportable s=new sportable () {public void Sport () {System.out.println ("playing basketball");}};S.sport ();System.out.println (S.getclass ());//class com.aowin.noname.test$3}}Entity classClass person{public void Eat () {System.out.println ("eat");}}

Have a nice smileAsk questionsHow does a Java lambda expression and stream work???solve the problemThe syntax of a lambda expressionBasic syntax:(parameters) -> expression或(parameters) ->{ statements; }Read the example study!Example one: Define a Ayperson class to prepare for subsequent tests.package com.evada.de;impor

This example describes the use of object classes in Java. Share to everyone for your reference. Specifically as follows: 1. The object class is the base class for all Java classes If the extends keyword is not used in the declaration of the

In the Java language, the string class has immutability, that is, constant strings cannot be changed. The following is a small example of a simple demonstration of related concepts.1 Public classTest {2 Public Static voidMain (String []args) {3String str1= "Hello";4 System.out.println (str1);5 Tell (STR1);6 System.out.print (STR1); 7 }8 9 Publi