java singleton implementation
public class SingletonClass {
private static final SingletonClass SINGLE_INSTANCE = new SingletonClass();
private SingletonClass() {}
public static SingletonClass getInstance() {
return SINGLE_INSTANCE;
}
}java singleton
- A private constructor
- A static field containing its only instance
- A static factory method for obtaining the instance
public final class ClassSingleton
{
private static ClassSingleton INSTANCE;
private String info = "Initial info class";
private ClassSingleton()
{
}
public static ClassSingleton getInstance()
{
if(INSTANCE == null)
{
INSTANCE = new ClassSingleton();
}
return INSTANCE;
}
// getters and setters
}
=============Usage============
To use our ClassSingleton, we simply need to get the instance statically:
ClassSingleton classSingleton1 = ClassSingleton.getInstance();
System.out.println(classSingleton1.getInfo()); //Initial class info
ClassSingleton classSingleton2 = ClassSingleton.getInstance();
classSingleton2.setInfo("New class info");
System.out.println(classSingleton1.getInfo()); //New class info
System.out.println(classSingleton2.getInfo()); //New class infojava singleton
public class SingletonOnDemand {
private SingletonOnDemand () {}
private static class Singleton {
private static final SingletonOnDemand instance = new SingletonOnDemand();
}
public static SingletonOnDemand getInstance () {
System.out.println("create instance");
return Singleton.instance;
}
}java singleton
public final class SomeSingleton {
public static final SomeSingleton INSTANCE;
private SomeSingleton() {
INSTANCE = (SomeSingleton)this;
System.out.println("init complete");
}
static {
new SomeSingleton();
}
}java singleton example
public final class ClassSingleton {
private static ClassSingleton INSTANCE;
private String info = "Initial info class";
private ClassSingleton() {
}
public static ClassSingleton getInstance() {
if(INSTANCE == null) {
INSTANCE = new ClassSingleton();
}
return INSTANCE;
}
// getters and setters
}Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
