定义:
将一个复杂的构建与他的表示分离,使得同样的构建过程可以创建不同的表示
建造者模式通常包括下面几个角色:
- builder:给出一个抽象接口,以规范产品对象的各个组成成分的建造。这个接口规定要实现复杂对象的哪些部分的创建,并不涉及具体的对象部件的创建。
public interface Build {
public void makeWindow();
public void makeFloor();
public Room getRoom();
}
- ConcreteBuilder:实现Builder接口,针对不同的商业逻辑,具体化复杂对象的各部分的创建。 在建造过程完成后,提供产品的实例。
public class ConcreteBuilder implements Build{
private Product room=new Product();
@Override
public void makeWindow() {
room.setFloor("地板 ");
}
@Override
public void makeFloor() {
room.setWindow("窗户");
}
@Override
public Product getRoom() {
return room;
}
}
- Director:调用具体建造者来创建复杂对象的各个部分,在指导者中不涉及具体产品的信息,只负责保证对象各部分完整创建或按某种顺序创建。
public class Director {
public void order(Build build)
{
build.makeFloor();
build.makeWindow();
}
}
- Product:要创建的复杂对象。
public class Product {
private String window;
private String floor;
public String getWindow() {
return window;
}
public void setWindow(String window) {
this.window = window;
}
public String getFloor() {
return floor;
}
public void setFloor(String floor) {
this.floor = floor;
}
@Override
public String toString() {
return "---->floor " + floor + " window " + window;
}
}
- 执行:
Build worker = new ConcreteBuilder();
Director director = new Director();
director.order(worker);
Log.d("huangxiaoguo",worker.getRoom().toString());
- 角色案例:
android中的builder设计模式
- 产品
/**
* 要建造一座房子
*/
public class House {
private final HouseController mAlert;
public House(Context context) {
//固定两百万
mAlert = new HouseController(this,200);
}
public static class Builder {
private final HouseController.AlertParams P;
public Builder(Context context) {
P = new HouseController.AlertParams(context);
}
/**
* 设置窗户
*
* @param window
* @return
*/
public Builder setWindow(String window) {
P.window = window;
return this;
}
/**
* 设置地板
*
* @param floor
* @return
*/
public Builder setFloor(String floor) {
P.floor = floor;
return this;
}
/**
* 设置门
*
* @param doorl
* @return
*/
public Builder setDoorl(String doorl) {
P.doorl = doorl;
return this;
}
/**
* 进行创建组装类
*
* @return
*/
private House create() {
final House house = new House(P.mContext);
P.apply(house.mAlert);
//----------------------------------------------------
//处理 House的其他方法和逻辑
//----------------------------------------------------
return house;
}
/**
* 然后进行展示(如果不是UI的显示,直接的逻辑处理直接调用create方法即可,
* 如果需要展示UI调用show方法更好统一展示)
* @return
*/
public House show() {
final House house = create();
return house;
}
}
}
- 组装产品
/**
* 房子的组装类
*/
public class HouseController {
private House mHouse;
private double mMoney;
public HouseController(House house, double money) {
this.mHouse = house;
this.mMoney = money;
}
public House getHouse() {
return mHouse;
}
public double getMoney() {
return mMoney;
}
public static class AlertParams {
public Context mContext;
public String window;
public String floor;
public String doorl;
public AlertParams(Context context) {
this.mContext = context;
}
/**
* 绑定和设置参数
*
* @param mAlert
*/
public void apply(HouseController mAlert) {
// 执行最后的装箱操作(一般复杂的逻辑,新建一个Helper类帮助解决)
double money = mAlert.getMoney();
Log.d("huangxiaoguo", "房价:" + money + ",设置窗户:" + window + ",设置地板:" + floor + ",设置门:" + doorl);
}
}
}
- 调用
House show = new House.Builder(this).setWindow("玻璃窗").setFloor("木地板").setDoorl("防盗门").show();