设计模式（3）builder

liu_chunhai2024-10-06 19:17

需求：对于复杂的对象，我们只需要通过设置一些参数，就可以得到相对应的实例。

简单来说，需求就是用一个类通过方法返回一个新建的对象，而且可以通过方法去设置这个对象

public interface CarBuilder {
    void setCarName(String name);
    void setCarModel(String model);
    Car getCar();
}

这个类有一个内部私有 car，通过getCar ，输出 car的实例。

package com.example.builder;

public class CarBuilderImp implements CarBuilder {
    private Car car = new Car ();
    @Override
    public void setCarName( String name) {
        car.setName(name);
    }

    @Override
    public void setCarModel(String model) {
        car.setModel( model);

    }

    @Override
    public Car getCar() {
        return car;
    }
}

package com.example.builder;

import android.util.Log;

import androidx.annotation.NonNull;

public class Car {
    String name;
    String model;

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

    public void setModel(String model) {
        this.model = model;
    }

    public String getName() {
        return name;
    }

    public String getModel() {
        return model;
    }

    @NonNull
    @Override
    public String toString() {
        Log.d("Car"+"LIU","name = " + this.name + "model = " + this.model);
        return this.name + this.model;
    }

}

example

        CarBuilderImp carBuilderImp = new CarBuilderImp();
        carBuilderImp.setCarModel("X1");
        carBuilderImp.setCarName("BMW");
        Car car = carBuilderImp.getCar();


2024-10-05 11:53:36.966 18346-18346/com.example.builder D/CarLIU: name = BMWmodel = X1

参考：百度安全验证

https://github.com/youlookwhat/DesignPattern#11-%E5%BB%BA%E9%80%A0%E8%80%85%E6%A8%A1%E5%BC%8F