java简单工厂模式

（缺点：每增加一个具体产品时 ，就要修改工厂方法，工厂方法负责了所有具体产品的创建）

举个例子：
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public interface Fruit {

void grow();

void harvest();

void plant();
}
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public class Apple implements Fruit {

private int treeAge;

public void grow() {
  // TODO Auto-generated method stub
  System.out.println("Apple is growing...");
 
}

public void harvest() {
  // TODO Auto-generated method stub
  System.out.println("Apple has been harvested.");
}

public void plant() {
  // TODO Auto-generated method stub
  System.out.println("Apple has been planted.");
 
}

public int getTreeAge() {
  return treeAge;
}

public void setTreeAge(int treeAge) {
  this.treeAge = treeAge;
}

}
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public class Grape implements Fruit {

private boolean seedless;



public boolean isSeedless() {
  return seedless;
}

public void setSeedless(boolean seedless) {
  this.seedless = seedless;
}

public void grow() {
  // TODO Auto-generated method stub
  System.out.println("Grape is growing...");
}

public void harvest() {
  // TODO Auto-generated method stub
  System.out.println("Grape has been harvested.");
}

public void plant() {
  // TODO Auto-generated method stub
  System.out.println("Grape has been planted.");
 
}


}


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public class Strawberry implements Fruit {

public void grow() {
  // TODO Auto-generated method stub
  System.out.println("Strawberry is growing...");
}

public void harvest() {
  // TODO Auto-generated method stub
  System.out.println("Strawberry has been harvested.");
}

public void plant() {
  // TODO Auto-generated method stub
  System.out.println("Strawberry has been planted.");
}
}

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public class FruitGardener {

//静态工厂方法
public static Fruit factory(String which) throws BadFruitException{
  if(which.equalsIgnoreCase("apple")){
   return new Apple();
  }
  else if(which.equalsIgnoreCase("strawberry")){
   return new Strawberry();
  }
  else if(which.equalsIgnoreCase("grape")){
   return new Grape();
  }
  else{
   throw new BadFruitException("Bad fruit request");
  }
}
}

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public class BadFruitException extends Exception {

public BadFruitException(String msg){
  super(msg);
}
}


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public class Client {

public static void main(String[] args){
 
  try{
   Fruit apple = (Fruit)FruitGardener.factory("Apple");
   System.out.println("apple is class: " + apple.getClass().getName());
   apple.plant();
   apple.grow();
   apple.harvest();
   System.out.println();
  
   Fruit grape = (Fruit)FruitGardener.factory("grape");
   System.out.println("grape is class: " + grape.getClass().getName());
   grape.plant();
   grape.grow();
   grape.harvest();
   System.out.println();
  
   Fruit strawberry = (Fruit)FruitGardener.factory("strawberry");
   System.out.println("strawberry is class: " + strawberry.getClass().getName());
   strawberry.plant();
   strawberry.grow();
   strawberry.harvest();
  
  }catch(BadFruitException e){
   e.printStackTrace();
  }
}
}


2 工厂方法模式：解决了简单工厂模式的缺点， 将每一个具体产品的创建工作交给对应的具体工厂角色去解决

举个例子：
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public interface FruitGardener {

public Fruit factory();
}


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public class AppleGardener implements FruitGardener{

public Fruit factory() {
  return new Apple();
}
}

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public class GrapeGardener implements FruitGardener{

public Fruit factory() {
  return new Grape();
}
}


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public class StrawGardener implements FruitGardener{

public Fruit factory() {
  return new Strawberry();
}
}

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public class Client {

private static FruitGardener applegardener, grapegardener, strawgardener;
private static Fruit apple, grape, strawberry;

public static void main(String[] args){
  applegardener = new AppleGardener();
  apple = applegardener.factory();
  System.out.println("apple is class: " + apple.getClass().getName());
  apple.plant();
  apple.grow();
  apple.harvest();
  System.out.println();
 
  grapegardener = new GrapeGardener();
  grape = grapegardener.factory();
  System.out.println("grape is class: " + grape.getClass().getName());
  grape.plant();
  grape.grow();
  grape.harvest();
  System.out.println();

  strawgardener = new StrawGardener();
  strawberry = strawgardener.factory();
  System.out.println("strawberry is class: " + strawberry.getClass().getName());
  strawberry.plant();
  strawberry.grow();
  strawberry.harvest();
}
}


3 抽象工厂模式：解决多产品簇问题

举个例子：

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public interface Fruit {

// public String getName();
}

public class NorthernFruit implements Fruit{

private String name;

public String getName() {
  return name;
}

public void setName(String name) {
  this.name = name;
}

public NorthernFruit(String name) {
  super();
  // TODO Auto-generated constructor stub
  this.name = name;
}


}



public class TropicalFruit implements Fruit{

private String name;

public String getName() {
  return name;
}

public void setName(String name) {
  this.name = name;
}

public TropicalFruit(String name) {
  super();
  // TODO Auto-generated constructor stub
  this.name = name;
}


}



public interface Veggie {

}


public class TropicalVeggie implements Veggie{

private String name;

public String getName() {
  return name;
}

public void setName(String name) {
  this.name = name;
}

public TropicalVeggie(String name) {
  super();
  // TODO Auto-generated constructor stub
  this.name = name;
}



}


public class NorthernVeggie implements Veggie{

private String name;

public String getName() {
  return name;
}

public void setName(String name) {
  this.name = name;
}

public NorthernVeggie(String name) {
  super();
  // TODO Auto-generated constructor stub
  this.name = name;
}


}

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public interface Gardener {

public Fruit createFruit(String name);

public Veggie createVeggie(String name);
}

public class NorthernGardener implements Gardener {

public Fruit createFruit(String name) {
  return new NorthernFruit(name);
}

public Veggie createVeggie(String name) {
  return new NorthernVeggie(name);
}


}



public class TropicalGardener implements Gardener {

public Fruit createFruit(String name) {
  return new TropicalFruit(name);
}

public Veggie createVeggie(String name) {
  return new TropicalVeggie(name);
}


}


public class Client {

private static Gardener tropicalgardener ,northerngardener;
private static Fruit northernfruit, tropicalfruit;
private static Veggie northernveggie, tropicalveggie;

public static void main(String[] args){
  tropicalgardener = new TropicalGardener();
  tropicalfruit = tropicalgardener.createFruit("tropicalfruit");
  //System.out.println(tropicalfruit.getName());
  tropicalveggie = tropicalgardener.createVeggie("tropicalveggie");
 
  northerngardener = new NorthernGardener();
  northernfruit = northerngardener.createFruit("northernfruit");
  northernveggie = northerngardener.createVeggie("northernveggie");
}

}