Original October 29, 2017 serious Xiao Su

Introduction to decoration mode

UML class diagram

Code practice

/**
 * Created by suful on 2017/10/29.
 * Define human as an abstract class
 * Abstract component class is also the original object we need to decorate
 */

public abstract class Person {
    /**
     * The abstract way to dress
     */
    public abstract void dressed();
}

/**
 * Created by suful on 2017/10/29.
 * Who is the specific decoration?
 * Define a boy class (Boy) - "belongs to human, inheriting the method of human to implement wearing
 */

public class Boy extends Person {
    @Override
    public void dressed() {
        System.out.println("Wearing underwear and underpants");
    }
}

/**
 * Created by suful on 2017/10/29.
 * (Boy) Class to decorate our body object, PersonCloth
 * <p>
 * Clothes people wear
 */

public abstract class PersonCloth extends Person {
    protected Person person;

    public PersonCloth(Person person) {
        this.person = person;
    }

    @Override
    public void dressed() {
        /**
         * Call the dressed() / method in the person class
         */
        person.dressed();
    }
}

/**
 * Created by suful on 2017/10/29.
 * Fancy clothes
 */

public class ExpensiveCloth extends PersonCloth {
    public ExpensiveCloth(Person person) {
        super(person);
    }

    @Override
    public void dressed() {
        super.dressed();
        dressShirt();
        dressLeather();
        dressJean();
    }

    private void dressShirt() {
        System.out.println("Wear short sleeves");
    }

    private void dressLeather() {
        System.out.println("Wear a leather coat");
    }

    private void dressJean() {
        System.out.println("Wear a pair of jeans");
    }
}

   /**
         * First of all, we need a boy
         */
        Person person = new Boy();

        /*
        * And put on cheap clothes for him
        * */
        PersonCloth personCloth = new CheapCloth(person);
        personCloth.dressed();

        /*Or dress him in fancy clothes*/
        PersonCloth personCloth1 = new ExpensiveCloth(person);
        personCloth1.dressed();

Reference book: analysis and practice of Android source code design pattern