java singleton example

Single-Case mode:1: Lazy TypePackage com.design;/* 1: Lazy type */public class Singleton {/*** Private, do not allow instances to be obtained externally through singleton.instance* Static method can only access static variables.*/private static Singleton instance;Private, not allowed to instantiate externallyPrivate Singleton () {}/*** Multithreading calls this m

Java design mode-singleton mode and template Mode 1. Singleton mode method: the class construction method is private. A static class object in the class is used to save this class object, and this class provides a static method to obtain this class object. /*** Singleton design mode ** @ author Admin **/public clas

The singleton pattern, as the name implies, is to ensure that a class is allowed only one instance in the program. This class can create a unique instance of itself and only provide this unique instance to the system. We usually say that there are five types of singleton patterns: a Hungry man, lazy, double lock, Static inner class, enumeration type. Among them, the A hungry man and the lazy type are the mo

Java: understanding of Singleton Preface: Java Singleton is often used. Today, I have a new understanding.Lazy Singleton package com.mwq.singleton;public class Singleton1 { private Singleton1() { } private static Singleton1 single = null; public static Singleton1

Previously only used the singleton mode, but did not know the meaning of the singleton model, today to interview let a class only instantiate once, think for a long time did not think out, back to check the data only know is a single case mode, record down.public class Singleton {private static Singleton uniqueinstance

At noon today, I am free to write something about the Java Singleton mode. In fact, there are many ways to implement the singleton mode. Here I will compare and analyze these methods: First: [Java]Public class Singleton2 {Private Singleton2 (){System. out. println ("This is Singleton2's instance .");};Private static Si

Design Patterns are often divided into the following three types: Creation type When creating an object, we do not directly instantiate the object. Instead, the program determines how to create the object based on the specific scenario. For example, factory method, abstract factory mode, and Singleton mode. ConstructorIt is used to organize multiple objects into a larger structure. Such as the adapter mode,

//-------------------------------------------------------------A hungry man mode--start------------------------------------------------ ----------- PackageCom.study.DesignPattern01;/*** Create a single instance of a Hungry man mode *@authorZlhome * Some objects, we only need one, if more, then it can lead to inconsistent data, excessive resources and so on, such as: Configuration file, tool class, thread pool, cache, log Object*/ Public classSingleton {//1, the construction method of privatizati

we get not a singleton object, but multiple objects. We have synchronized optimizations for these.public static class singleton{ private static Singleton instance=null; Private Singleton () { //do something } public static Singleton getinstance () {

Java implementation Singleton mode 1. The simplest way: public class Singleton { private static final Singleton singleton = new Singleton(); private Singleton(){ }

/** * The second method of implementing Singleton, a common member is a static factory method. * (the public static member in the first method is a final domain, that is, the direct use of private static final Singleton INSTANCE = new Singleton ();) * @author Liu Xiangfeng * */ Public class Singleton { Private Stat

The source code section of the runtime class is as follows:/*runtime part of the source code, to others bragging small capital *public class runtime{* Private Runtime () {} * private static runtime currentruntime = new Runt IME (); * public static Runtime GetRuntime () {* return currentruntime; *} *} * *//design pattern (Java code in singleton mode embodies runtime Class)/** Runtime: This is the JDK provide

pool overflow, if the instantiated object is not exploited for a long time,The system is considered garbage and is recycled by GC resulting in loss of object state　　Lazy mode:　　　　　　A Hungry man mode:Dual Lock mode:　　　　　　Summarize:　　1, lazy mode features: Thread insecure, load classes faster, run time to get objects slower,2, a Hungry man mode features: Thread safety, load class is slow, run time to get objects faster3, double lock mode: Thread-safe, load class faster, run-time to get objects at

Java design mode-Singleton)Objective: To ensure that a class can only instantiate one object and provide a global access point.When to use: When a class only instantiates an object. Typical use: log class management database connection IO, actual example of file operations: java. lang. Runtime # getRuntime () sample co

Java has 21 kinds of design patterns, which are often asked in the interview is a single case design mode;The singleton design pattern has two common ways: 1. Lazy: 1) First privatize the constructor so that the class cannot be instantiated, (private class name () {}), 2) Instantiate an empty object in the class itself, (private static class name =null;); 3) construct a method , returns the object of this c

Now read the Java Concurrency Book, record it. For the Java singleton pattern, the correct code should be:public class Testinstance { Private volatile static testinstance instance; public static Testinstance getinstance () {//1 if (instance = = null) { //2 synchronized (testinstance.class) {//3 if (instance

Singleton is a creation model that ensures that only one instance is generated and provides a global access point to access it. for some classes, it is very important to ensure only one instance. For example, sometimes database connections or socket connections are restricted, and only one connection can exist at a time. for another example, the set in the set ca

Public class Singleton {Private static Singleton instance = null; private Singleton () {} private static synchronized void syncInit () {if (instance = null) {instance = new Singleton ();}} public static Singleton getInstance () {if (instance = null) {syncInit ();} return ins

JAVA Static method and Singleton Mode Recently, when I used sonar to evaluate the code quality, I found a problem. Some util classes in the project, the static methods previously written, all prompted that it is best to use the singleton Method for correction. For this reason, I thought carefully and found that it still makes sense. Here I will talk about my pers

Lazy Type Public classsingleton{//@ Singleton class can have only one instance//@ Singleton class must create this instance on its own//@ Singleton class must provide this instance to all objects//This example must be provided to the system as a whole Private StaticSingleton uniqueinstance =NULL; PrivateSingleton ()