Builder设计模式——化妆师

菜鸟正在努力学习中，如有出入，往大佬扶正，谢谢！！！

将一个复杂的对象的构建和它的表示分开，使得同样的构建过程可以创建不同的表示

cover

左图经过一系列的手法变成了右图，反正我喜欢右图,废话不多说，看代码

/**
 * 美女类
 */
public class Belle {

    //隔离霜
    private String mSunScreen;
    //粉底
    private String mFoundation;
    //眼影
    private String EyeShadows;
    //口红
    private String mLmipstick;

    public Belle(Builder builder) {
        this.mSunScreen = builder.mSunScreen;
        this.mFoundation = builder.mFoundation;
        this.EyeShadows = builder.mEyeShadows;
        this.mLmipstick = builder.mLmipstick;

    }

    @Override
    public String toString() {
        return "Belle{" +
                "mSunScreen='" + mSunScreen + '\'' +
                ", mFoundation='" + mFoundation + '\'' +
                ", EyeShadows='" + EyeShadows + '\'' +
                ", mLmipstick='" + mLmipstick + '\'' +
                '}';
    }

    public static class Builder {

        private String mSunScreen = "SunScreen";
        private String mFoundation = "Foundation";
        private String mEyeShadows = "EyeShadows";
        private String mLmipstick = "Lmipstick";

        public Builder() {
        }

        /**
         * 隔离霜
         *
         * @param sunScreen
         */
        public Builder setSunScreen(String sunScreen) {
            this.mSunScreen = sunScreen;
            return this;
        }


        /***
         * 设置粉底
         * @param foundation
         */
        public Builder setFoundation(String foundation) {
            this.mFoundation = foundation;
            return this;
        }


        /**
         * 设置眼影
         *
         * @param eyeshadows
         */
        public Builder setEyeShadows(String eyeshadows) {
            this.mEyeShadows = eyeshadows;
            return this;
        }


        /**
         * 设置口红
         *
         * @param lmipstick
         */
        public Builder setLmipstick(String lmipstick) {
            this.mLmipstick = lmipstick;
            return this;
        }


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

    }
}

关键：在于set 返回的是当前的对象(this 链条式的基础)。
优点：将配置从目标类隔离出来，避免了过多的setter()方法，容易扩展。
缺点：会产生多余的Builder对象。

大佬，冲我的图，点个赞再走~~~