Java: Two common design patterns (singleton mode and Factory mode)

One, Singleton mode: That is, a class from beginning to end only one instance. There are two ways to implement
(1) defines a class whose construction method is private and has a private static variable that is instantiated at initialization time and obtains the object through a public static method.
Java code
1.//The first form of the singleton pattern
2. public class Singleton01 {
3.
4.//private static properties
5. private static Singleton01 instance = new Singleton01 ();
6.
7.//Private method of construction
8. Private Singleton01 () {
9.}
10.
11.//public static method
public static Singleton01 getinstance () {
return instance;
14.}
15.}
(2) The improved
Java code
1. public class Singleton02 {
2.
3.//private Static class variable
4. private static SINGLETON02 instance = NULL;
5.
6.//Private method of construction
7. Private Singleton02 () {
8.}
9.
10.//Static Public method
public static Singleton02 getinstance () {
if (instance = = null) {
Instance = new Singleton02 ();
14.}
. return instance;
16.}
17.}

second, the factory model: the production of different objects of the public interface
(1) Product interface
Java code
1.//Product interface
2. Public interface Product {
3.
4.}
(2) Product Interface implementation class
Java code
1.//washing machine
2. Public class Washer implements PRODUCT {
3.
4. Public washer () {
5. SYSTEM.OUT.PRINTLN ("The washing machine was made!" ");
6.}
7.}
Java code
1.//Air Conditioning
2. Public class Aircondition implements Product {
3.
4. Public aircondition () {
5. SYSTEM.OUT.PRINTLN ("Air conditioner is manufactured! ");
6.}
7.}
(3) Factory interface
Java code
1.//Factory interface
2. Public interface Factory {
3.
4.//Production of products
5. Product Produce (String productName);
6.
7.}
(4) The implementation class of the factory
Java code
1.//Implement Factory
2. Public class Testfactory implements Factory {
3.
4.//Production of products
5. Public Product Produce (String productName) {
6. if (Productname.equals ("washer")) {
7. Return new washer ();
8.}
9. if (Productname.equals ("aircondition")) {
return new Aircondition ();
11.}
return null;
13.}
14.
public static void Main (string[] args) {
Testfactory testfactory = new Testfactory ();
Testfactory.produce ("washer");
Testfactory.produce ("aircondition");
19.}
20.}

Java: Two common design patterns (singleton mode and Factory mode)