1. Decorate and have a common super class with the decorated person
2. The purpose of inheritance is to achieve type inheritance (thus realizing the extension of behavior)
3. Behavior extension (final purpose)
scenario: have the main type or business Logic, but with personalized processing scenarios
Example : Different coffees have different prices, but the price calculation model is the same The
code is as follows
/**
* Super coffee
* @author john
*
*/
public abstract class Coffe {
//price
public abstract double cost();
}
/**
* Mocha coffee (decorated)
* @author john
*
*/
public class MokaCoffe extends Coffe {
@Override
public double cost() {
// TODO auto-generated method stub
return 2.0;
}
}
/**
* Nes coffee decorator
* @author john
*
*/
public class NesCoffe extends Coffe {
@Override
public double cost() {
// TODO auto-generated method stub
return 3.0;
}
}
/**
* Seasoning component (decorator component)
* @author john
*
*/
public abstract class CompentDecorate extends Coffe {
@Override
public abstract double cost();
}
/**
* Cream Dressing (for garnish)
* @author john
*
*/
public class MilkCondiment extends CompentDecorate {
private Coffe coffe;
public MilkCondiment(){
}
public MilkCondiment(Coffe coffe){
this.coffe = coffe;
}
@Override
public double cost() {
// TODO auto-generated method stub
return 0.2+coffe.cost();
}
}
/**
* sugar seasoning (decorator)
* @author john
*
*/
public class sugarCondiment extends CompentDecorate {
private Coffe coffe;
public sugarCondiment(){
}
public sugarCondiment(Coffe coffe){
this.coffe = coffe;
}
@Override
public double cost() {
// TODO auto-generated method stub
return 0.1+coffe.cost();
}
}
public class Test {
public static void main(String[] args){
//coffee 2.0
Coffe mokaCoffe = new MokaCoffe();
//extended behavior (price)
//Coffee with milk 0.2
mokaCoffe = new MilkCondiment(mokaCoffe);
System.out.println(mokaCoffe.cost());
// sweetened coffee 0.1
mokaCoffe = new sugarCondiment(mokaCoffe);
System.out.println(mokaCoffe.cost());
}
}
//Run result:
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