Builder模式

2017-06-17  本文已影响15人  王小贱_ww

Builder模式?(好熟悉,貌似有说不上来),在这里好好总结一下。

Builder模式的介绍

Builder模式是一步一步创建一个复杂对象的创建者模式, 它允许用户在不知道内部构建细节的情况下,可以精确的控制对象的构造流程。该模式为了将构建复杂对象的过程和它的部件解耦,将一个复杂对象的创建与它的表示分离,使得同样的构建过程可以创建不同的表示,

Builder模式的角色介绍

代码

public abstract class Product {
/**
 * 计算机抽象类(Product)
 */

    protected  String mBoard;
    protected  String mDisplay;
    protected  String mOs;

    public void setmBoard(String mBoard) {
        this.mBoard = mBoard;
    }

    public void setmDisplay(String mDisplay) {
        this.mDisplay = mDisplay;
    }
    //设置操作系统,让子类自己去实现
    public abstract  void setmOs();
}
public class MacBook extends Product {
/**
 * 具体的Computer类, MacBook
 */

    @Override
    public void setmOs() {
        mOs = "苹果系统10.00";
     }
}
public abstract class Builder {
/**
 * 抽象Builder
 */

    public abstract void buildBoard(String board);

    public abstract void buildDisplay(String display);

    public abstract void buildOs();

    public abstract Product create();
}
public class MacbookBuilder extends Builder {
/**
 * 具体的Builder
 */
    private Product product = new MacBook();

    @Override
    public void buildBoard(String board) {
        product.setmBoard(board);
    }

    @Override
    public void buildDisplay(String display) {
        product.setmDisplay(display);
    }

    @Override
    public void buildOs() {
        product.setmOs();
    }

    @Override
    public Product create() {
        return product;
    }
}
public class Director {
/**
 * Director 负责构建product
 */
    private Builder builder = null;

    public Director(Builder builder) {
        this.builder = builder;
    }

    public void construct(String board, String display) {
        builder.buildBoard(board);
        builder.buildDisplay(display);
        builder.buildOs();
    }
}
public class Test {
    public static void main(String[] args) {
        Builder builder = new MacbookBuilder();
        Director director = new Director(builder);
        director.construct("英特尔", "25寸");
        System.out.println(builder.create().toString());

    }
}
在实际的Android开发中,我们一般这样应用
 Person person = new Person.Builder().setName("test").......set.....build();


    public class Person {
    private String name;//用户不知道有哪些参数(参数太多)

    public Person(Builder builder) {
        name = builder.name;
    }


    public static class Builder {

        private String name;

        public Builder setName(String str) {
            name = str;
            return this;
        }

        public Person build() {
            return new Person(this);
        }
    }
}

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