# design-pattern

**Repository Path**: ganyipeng/design-pattern

## Basic Information

- **Project Name**: design-pattern
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-07-07
- **Last Updated**: 2024-07-07

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

## 1、单例模式

### 1、概念

> 私有构造函数

### 2、UML类图

![单例模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLWZEp4lFINK6iQkv51HqaGMi53BpWChpabFHPJGqWIBQg6hJKqiyeSg1qhLSI98Akhfso8gv75BpKe1k0000)

### 3、java示例代码

```java
public class SingleClass {
    // 静态私有实例
    private static SingleClass instance = new SingleClass();

    // 私有构造函数
    private SingleClass(){}
    
    // 静态公共方法
    public static SingleClass getInstance(){
        return instance;
    }
}
```

## 2、工厂模式

### 1、概念

> 具体的工厂产生具体的子类

### 2、UML类图

![工厂模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8ACfFAKqkuKhEIImkXl4S5J9p2t9ISrFpIegngt0YgC8PcmfCYzqIaqloYoghkHGKj65YLkcf9L2cXYPNBSHSD0t8JgJKB2SgckLCfbbSg6eLz8303Xvkw7v7bdH4atL2aNL2atL6aNNcSaZDIm6c2000)

### 3、java示例代码

```java
interface Product{}
class ProductA implements Product{}
class ProductB implements Product{}
class ProductC implements Product{}

interface ProductFactory{
    Product getProduct();
}
class ProductFactoryA implements ProductFactory{
    public Product getProduct(){
        return new ProductA();
    }
}
class ProductFactoryB implements ProductFactory{
    public Product getProduct(){
        return new ProductB();
    }
}
class ProductFactoryC implements ProductFactory{
    public Product getProduct(){
        return new ProductC();
    }
}
```

## 3、抽象工厂模式

### 1、概念

> 具体工厂产生一系列具体对象

### 2、UML类图

![抽象工厂模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8ACfFAKqkSSGKSkBYIiv9B2w6Ap5KoCmjo4dDJSqhGGYYgd52LeFJ82CY33B2QX2cAzqIaqloYoghkHGKjE5cMQMdbi3O6fh8Kav8Kav0gLg8jMYc8Vk2fXOPqS8YBbI35FI0m0vk4bvP9oxqW43HQuXNsWbTsWXLjn5UQISZBeVKl1HWwWG0)

### 3、java示例代码

```java
interface ProductA{}
interface ProductB{}

class ProductA1 implements ProductA{}
class ProductB1 implements ProductB{}

class ProductA2 implements ProductA{}
class ProductB2 implements ProductB{}

interface ProductFactory{
  public ProductA getProductA(){}
  public ProductB getProductB(){}
}

class ProductFactory1 implements ProductFactory{
  public ProductA getProductA(){
    return new ProductA1();
  }
  public ProductB getProductB(){
    return new ProductB1();
  }
}
class ProductFactory2 implements ProductFactory{
  public ProductA getProductA(){
    return new ProductA2();
  }
  public ProductB getProductB(){
    return new ProductB2();
  }
}
```

## 4、装饰器模式

### 1、概念

> 相同父类且关联具体子类，起到增加功能的目的

### 2、UML类图

![装饰器模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8ACfFAKqkgUPIKD1MAClFJB5AoG_EpqqDoSZCIzVGvAhbuahEIImkXYbqLCZCBSX9pKtDAoach1bLhqjgSdvHOab-4GupT64Sgm883J8NGxC6L40JZvCnBDG30ZkOKLmEgNafm6000000)

### 3、java示例代码

```java
interface Product{
  public void doSomeThing();
}

class ProductA implements Product{
  public void doSomeThing(){

  }
}
class ProductDecorator implements Product{
  private Product product;
  public ProductDecorator(Product product){
    this.product = product;
  }
  public void doSomeThing(){
    // 做一些事情
    product.doSomeThing();
    // 做另外一些事情
  }
}
```

## 5、适配器模式

### 1、概念

> 起到类型转换的目的

### 2、UML类图

![适配器模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbLmvE9ApaaiBbPmKiZCBSX9pKtDAob6Y3gc91O0bQB8LNCfAEWgE5abMGCPsZ0b6awQNBLSN30DUdOAJbmEgNafGEi0)

### 3、java示例代码

```java
interface A{}

class B implements A{}

class Adapter implements A{
  B b;
  public Adapter(B b){
    this.b = b;
  }
}
```

## 6、观察者模式

### 1、概念

> 一个类的变化能触发多个其他类的监听

### 2、UML类图

![观察者模式类图](https://www.plantuml.com/plantuml/png/TSx12i8m3CRnUvuYnmtf2qoHJQ-2pr3N30ffAqqs5F7TzT2g1tVxoly7JIzgiyw1mKUbFDcHy7mHoWjb6DcAV9u3-d1b2XHLripXhodecABIJH-0QF3aHNTLx3jCPShsdJUu9EywjCvLqjJH_lIOr4_tWRb6QLfu0fIVC1dplQAdwER0Bm00)

### 3、java示例代码

```java
interface Observer{
  void xxx();
}
class ObserverA implements Observer{
  public void xxx(){
    // aaa
  }
}
class ObserverB implements Observer{
  public void xxx(){
    // bbb
  }
}

class Context{
  private List<Observer>: observers;
  public void addObserver(Observer observer){
    this.observers.add(observer);
  }
  public void notifyAllObservers(){
    this.observers.forEach(observer->observer.xxx());
  }
}
```

## 7、外观模式

### 1、概念

> 不同类多个方法的调用，集中到一个类一个方法的调用中

### 2、UML类图

![外观模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLd06aOxLN0eAsWfb-Paf2hcf9HdvAOuQcboro4gSC9GueIjnnb3YZAx4BJ4vCIKLGrq4M1qNaX85FJqxgDkm2pjX5tRcSaZDIm5w3m00)

### 3、java示例代码

```java
class ClassA{
  void methodA(){}
}
class ClassB{
  void methodB(){}
}
class ClassC{
  void methodC(){}
}
class ClassFacade{
  void methodX(){
    new ClassA().methodA();
    new ClassB().methodB();
    new ClassC().methodC();
  }
}
```

## 8、状态模式

### 1、概念

> 关联状态，状态变化会导致行为变化

### 2、UML类图

![状态模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8BaaiIQtcKb3GLaZ93yxFJIt9oCnBrt3E1wgeAD7agkLApaaiBeQeCrJ8p2t8ISrDpIif9asd4JaweG8WbReGJLOAnI0AhBKiFpC5o4yj0SjeW4bD34D1fd513LBGqxE3cCFba9gN0Wm80000)

### 3、java示例代码

```java
interface State{
  public void doSomething(Context);
}
class State1 implements State{
  public void doSomething(Context){}
}
class State2 implements State{
  public void doSomething(Context){}
}
class Context{
  private State state;
  public void setState(State state){
    this.state = state;
  }
  public void doSomething(){
    state.doSomething();
  }
}
```

## 9、策略模式

### 1、概念

> 关联策略，策略变化会导致行为变化

### 2、UML类图

![策略模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8oC_9JAwivb9Gq5P8oG_EpqqjoSZCIzTmpWSggIZHvAhbIiv9B2w6AZHKoCmjo4dDJSqhAIPLhn5PUg4289MwK5rM2WLW6govB3ypnKgXEBK48gS1eJGn30QPo0KrJ45Fpmvg5fT3QbuAC4W0)

### 3、java示例代码

```java
interface Policy{
  public void doSomething(Context);
}
class Policy1 implements Policy{
  public void doSomething(Context){}
}
class Policy2 implements Policy{
  public void doSomething(Context){}
}
class Context{
  private Policy policy;
  public void setPolicy(Policy policy){
    this.policy = policy;
  }
  public void doSomething(){
    policy.doSomething();
  }
}
```

## 10、代理模式

### 1、概念

> 同一个父类，关联target

### 2、UML类图

![代理模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbNmhNJEIImkhkPIKD1MAClFJB5AoG_EpqqDoSZCIzVGvAhbuae6AO0fT5J8p2t8ISrDpIif9gmPJMywK1SE_RemZXNGZUcf9I0ZKVHfG3cQU5oAOe-U7Lm_bqDgNWhGtm00)

### 3、java示例代码

```java
interface MyClass{
  public void doSomeThing();
}

class MyClassA implements MyClass{
  public void doSomeThing(){

  }
}
class MyClassDecorator implements MyClass{
  private MyClass target;
  public MyClassDecorator(MyClass target){
    this.target = target;
  }
  public void doSomeThing(){
    // 做一些事情
    target.doSomeThing();
    // 做另外一些事情
  }
}
```

## 11、责任链模式

### 1、概念

> 处理之后调用next继续处理

### 2、UML类图

![责任链模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8IYqkoCyhpapApCaigLIevb9Gq5OeJYtnIwqeqK2Lr0JBfUG7v-UcbcHavgLhQ7BLSYNd91ONAmGPAcJc5kIavgRcbHHZCrGNNJ0FQ06vbXdHqp9ZIYr3bIRAQYvWUEhP0JtA5MG4PXXpEQJcfG2Z3W00)

### 3、java示例代码

```java
interface Responsibility {
  public void setNext(Responsibility);
  public void doSomething();
}
class R1 implements Responsibility {
  private Responsibility next;
  public void setNext(Responsibility responsibility){
    this.next = resposibility;
  }
  public void doSomething(){
    // doSomething
    this.next.doSomething();
  }
}
class R2 implements Responsibility {
  private Responsibility next;
  public void setNext(Responsibility responsibility){
    this.next = resposibility;
  }
  public void doSomething(){
    // doSomething
    this.next.doSomething();
  }
}
class R3 implements Responsibility {
  private Responsibility next;
  public void setNext(Responsibility responsibility){
    this.next = resposibility;
  }
  public void doSomething(){
    // doSomething
    this.next.doSomething();
  }
}
```

## 12、模板方法模式

### 1、概念

> 父类定义模板方法，子类重写某个子方法

### 2、UML类图

![模板方法模式类图](//www.plantuml.com/plantuml/png/SoWkIImgAStDuKfCAYufIamkKKZEIImkLd24Sft1l6ek1GLjXUAIr0933KqusmY9RGnbbwJc5kGabgG2kRLS4AESy_EIYr9BKi566Ifa0XMavgRcbU2n19Tk8s9q6-7IRKoatGXFWKroICrB0OOG0000)

### 3、java示例代码

```java
abstract class AbstractClass {
  public void step1();
  public void step2();
  public void step3();
  public void template(){
    this.step1();
    this.step2();
    this.step3();
  }
}
class ConcreteClass1 implements AbstractClass {
  public void step1(){
    System.out.println("xxx");
  }
}
class ConcreteClass2 implements AbstractClass {
  public void step2(){
    System.out.println("xxx");
  }
}
class ConcreteClass3 implements AbstractClass {
  public void step1(){
    System.out.println("xxx");
  }
  public void step3(){
    System.out.println("xxx");
  }
}
```

## 13、享元模式

### 1、概念

> 定义Map来减少对象的创建

### 2、UML类图

![享元模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLd3BgGnFpKpFAAdcgkL25tDBJ2x9BwfKgEPIKD1Ly4Wipl1DB50eoC_F0GfeAwIdbi2LQWIN56NcfIjafrPgWap2C2DVLnTXC9T3QbuAq140)

### 3、java示例代码

```java
class FlyWeight{
}

class FlyWeightFactory {
  private HashMap<String, FlyWeight> pool = new HashMap<>();
  public FlyWeight getFlyWeight(String key){
    // 代码
  }
}
```

## 14、命令模式

### 1、概念

> 关联命令，命令变化会导致行为变化

### 2、UML类图

![命令模式模式类图](https://www.plantuml.com/plantuml/png/VOun3i8m34Ltdy8Z2FKALQLEh722A34G4Jl8SRiWxev4v6vbieV_djxKBAWjN22BaTv299mhSv24Rq0yOQhNocIFBFV34JuGIsWDpxBM9-blCsn4xFSFDrU9IaPEP7uLOX9hBkd62yMyagBsks_qvKwjTmxZ5Wd-3AF3C96aXSiN)

### 3、java示例代码

```java
interface Command {
  public void doSomething();
}
class Invoker {
  private Command command;
  public void doSomething(){
    this.command.doSomething();
  }
}
class ConcreteCommand implements Command{
  private Reciver reciver;
  public void doSomething(){
    this.reciver.doSomething();
  }
}
class Reciver {
  public void doSomething(){}
}
```

## 15、生成器模式

### 1、概念

> ProductBuilder来分步骤创建Product

### 2、UML类图

![生成器模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLWWeoayfJIvHgEQgHHLnAitCIKaj0aeeA6Wh59Ua5XXgQCBPHaXiOoWxFRK4gXSeKCk5PewU7SnaBeVKl1IW2m00)

### 3、java示例代码

```java
class Product {
}
class ProductBuilder {
  Product product = new Product();
  public ProductBuilder step1(){
    // xxx
    return this;
  }
  public ProductBuilder step2(){
    // xxx
    return this;
  }
  public ProductBuilder step3(){
    // xxx
    return this;
  }
  public ProductBuilder getProduct(){
    return this.product;
  }
}
```

## 16、原型模式

### 1、概念

> clone克隆

### 2、UML类图

![原型模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbK8ACeloI-fB4XLgEPIKD1My4_AIaqkiL98pidFIzNGvAhbIiv9B2vMYAYeKCZCBSX9pKtDAob6QCEboo4rBmLe4m00)

### 3、java示例代码

```java
interface Prototype {
  public Object clone();
}
class Xxx implements Prototype{
  public Object clone(){
    return xxx;
  }
}
```

## 17、备忘录模式

### 1、概念

> 生成快照，可以撤销

### 2、UML类图

![备忘录模式类图](https://www.plantuml.com/plantuml/png/JOz1oeCm48NtESKibHyzWFo8KEYgfOjwWQ4P9DGaa1cb8BrxYIRgAk5xBtml7Gi6cUoeNYComoEOmJWK7s1H07zm9qjEF33Ez1GKwdr2HRaMPcyq32HhU0tUvZY_J6UflicHWsKd5mpKuvisQGKtm_AVQcq3Thj5kYiRGArt1qTvUHxSn4s5SGB6QVf4--blTTtceZhalgeEt97Janr_)

### 3、java示例代码

```java
class Originator {
  public Memento saveStateToMemento(){}
  public void getStateFromMemento(Memento Memento){}
}
class Memento {
}
class CareTaker {
  private List<Memento>: mementoList
  public void: add(Memento state){}
  public Memento get(int index){}
}
```

## 18、迭代器模式

### 1、概念

> 返回Iterator来遍历容器

### 2、UML类图

![迭代器模式](//www.plantuml.com/plantuml/png/bOv12i8m44NtESKi5S43P245Lsxq3DFurKWoaMGAWdXtiQLfNKcNy-R_ns-ASjOk1kD5aI_iG0T5PatvPOWsrAOKm6BfnkM8fwxMFJwrTpYr90Dwp_hx9CfUC0Ygpj8LEXvznGKkvHjt6OhnHJu-0Y942rMsRCklkEwPcoVuR-MKtEvgp3IGSnV31m00)

### 3、java示例代码

```java
interface Iterator{
  public boolean hasNext();
  public Object next();
}
interface Container{
  public Iterator getIterator();
}

class ConcreteIterator implements Iterator {
  public boolean hasNext(){}
  public Object next(){}
}
class ConcreteContainer implements Container {
  public Iterator getIterator(){}
}
```

## 19、组合模式

### 1、概念

> 用来模拟树状结构

### 2、UML类图

![组合模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuShCAqajIajCJbLmpiyjoCzBpIlXuahEIImkLl19JKnJIAqeISrBAKR8LdFLWkMXGiMP9QcOYXIgkHGKT1LyCejBRE22TbOAoHcPEIb5gNb0Cn2wy_Nqx91iTm0Q1NGP0000)

### 3、java示例代码

```java
interface Component{}

class Leaf extends Component{
}
class Composite extends Component {
  private List<Component> children = new ArrayList<>();
}
```

## 20、桥接模式

### 1、概念

> 通过关联来减少继承的爆炸

### 2、UML类图

![组合模式类图](ROyn2W9134Nxd28Ns0jOo8gLhJSOP_z2O2OZIGH1lBjRYAROClptUVcpHx5uz4QY0LjB1Pzk7bPgo52ghRZp5QiebXGmdW5TFCClOfxuqkyD7Hh33Yp_WzwK78dwEiv3go6GafyaqxJpp7JSgzEybRTf7m00)

### 3、java示例代码

```java
interface Abstraction{}
class RefinedAbstraction extends Abstraction{
  private Implementor implementor;
  public RefinedAbstraction(Implementor implementor){
    this.implementor = implementor;
  }
}

interface Implementor
class ConcreteImplementor extends Implementor{}
```

## 21、中介者模式

### 1、概念

> 网状的类关系，改为星状关系

### 2、UML类图

![组合模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLd3Epot8pqlDAt6ivb9Gq5M8oiZFI_VAJBLIg8Aok6hHbJeHhzGPZrA8MhWSH2N2FLOAYQWYJbOAIQWYpbOAoK23O2OewEhQ8Hc0Gzm9XxWp5q8hM0Qc327kX4FS6LNS8JKl1HZ20000)

### 3、java示例代码

```java
class ComponentA{
  private ZhongJie = zhongJie;
}
class ComponentB{
  private ZhongJie = zhongJie;
}
class ComponentC{
  private ZhongJie = zhongJie;
}

class ZhongJie{
  private ComponentA = a;
  private ComponentB = b;
  private ComponentC = c;
}
```

## 22、访问者模式

### 1、概念

> 针对同一个结构化信息，不同的访问者看到的内容是不一样的

### 2、UML类图

![访问者模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKhEIImkLWZEpqrr1hEgkHGKj1NACeipIpJ2G6H-aIPNBLTcNabgKLfYSge2L12YBYS_Fri3hXce468UJ96XGcPkGKvgRcfUIJ596er8q8XmkvwU7Kmn5vG6Yy5LS3cavgK0VGq0)

### 3、java示例代码

```java
class SomeClass {
  public void visit(Visitor visitor){
    visitor.look(this);
  }
}
interface Visitor{
  public void look(SomeClass target);
}
class Visitor1 implements Visitor{
  public void look(SomeClass target){
    // 观察信息1
  }
}
class Visitor2 implements Visitor{
  public void look(SomeClass target){
    // 观察信息2
  }
}
```

## 23、解释器模式

### 1、概念

> 对一段文本进行解释

### 2、UML类图

![解释器模式类图](https://www.plantuml.com/plantuml/png/SoWkIImgAStDuKfCAYufIamkKKZEIImkLd2jA2XABIxEpC-hvb9Gq5R8p2j9BG8AbQHgQ7BLSd51L8Ma5kLcvYNc85Ghf5QKfEQb4380gjylFuzI8vppWQ8L9GhLG147e3QWNm00)

### 3、java示例代码

```java
abstract class Expression{
  public void interprete(){}
}

class TerminalExpression extends Expression{
  public void interprete(){}
}
class NonTerminalExpression extends Expression{
  public void interprete(){}
}
class Context {
}
```