设计模式之过滤器模式

过滤器模式

package test;
import java.util.List;
public interface Filter {
	public List<Computer> filter(List<Computer> regulars);

}

package test;
public class Computer {
	private Brand brand;
	private Type type;
	private int price;
		
	public Computer(Brand brand, Type type, int price) {
		this.brand = brand;
		this.type = type;
		this.price = price;
	}

	public Brand getBrand() {
		return brand;
	}

	public void setBrand(Brand brand) {
		this.brand = brand;
	}

	public Type getType() {
		return type;
	}

	public void setType(Type type) {
		this.type = type;
	}

	public int getPrice() {
		return price;
	}

	public void setPrice(int price) {
		this.price = price;
	}

	@Override
	public String toString() {
		return "Computer [brand=" + brand + ", type=" + type + ", price=" + price + "]";
	}
}
enum Brand {
	Apple("apple"), HUAWEI("hauwei"), Haier("haier"), DELL("dell"), HP("hp");
	private String brand;
	Brand(String brand) {
		this.brand = brand;
	}
	public String getBrand() {
		return brand;
	}

}
enum Type {
	NOTEBOOK("notebook"), DESKTOP("desktop");
	private String type;

	Type(String type) {
		this.type = type;
	}

	public String getType() {
		return type;
	}
}

package test;
import java.util.ArrayList;
import java.util.List;
public class BrandFilter implements Filter {
	private Brand brand;
	public BrandFilter(Brand brand){
		this.brand = brand;
	}
	@Override
	public List<Computer> filter(List<Computer> regulars) {
		// TODO Auto-generated method stub
		List<Computer> result = new ArrayList<>();
		for(Computer regular:regulars){
			if(regular.getBrand().equals(brand)){
				result.add(regular);
			}
		}
		return result;
	}
}

package test;

import java.util.ArrayList;
import java.util.List;

public class TypeFilter implements Filter {	
	private Type type;
	public TypeFilter(Type type) {
		this.type = type;
	}
	@Override
	public List<Computer> filter(List<Computer> regulars) {
		List<Computer> result = new ArrayList<>();
		for(Computer regular:regulars){
			if(regular.getType().equals(type)){
				result.add(regular);
			}
		}
		return result;
	}

}

package test;

import java.util.ArrayList;
import java.util.List;

public class PriceFilter implements Filter {
	private int price;

	public PriceFilter(int price) {
		this.price = price;
	}
	@Override
	public List<Computer> filter(List<Computer> regulars) {
		List<Computer> result = new ArrayList<>();
		for(Computer regular:regulars){
			if(regular.getPrice() == price){
				result.add(regular);
			}
		}
		return result;
	}
}

package test;
import java.util.ArrayList;
import java.util.List;
public class FilterUtils{
	public static List<Computer> filter(List<Computer> regulars ,List<Filter> filters) {
		// TODO Auto-generated method stub
		List<Computer> result = new ArrayList<>(regulars);
		for(Filter filter: filters){
			result =filter.filter(result);
		}
		return result;
	}
}

package test;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class Test {
	public static void main(String[] args) {
		List<Computer> regulars = new ArrayList<>();
		regulars.add(new Computer(Brand.Apple,Type.NOTEBOOK,8000));
		regulars.add(new Computer(Brand.Apple,Type.NOTEBOOK,8000));
		regulars.add(new Computer(Brand.DELL,Type.DESKTOP,3000));
		regulars.add(new Computer(Brand.HP,Type.NOTEBOOK,6000));
		regulars.add(new Computer(Brand.DELL,Type.NOTEBOOK,8000));
		regulars.add(new Computer(Brand.Haier,Type.DESKTOP,6000));
		regulars.add(new Computer(Brand.HUAWEI,Type.NOTEBOOK,8000));
		System.out.println("库存信息");
		System.out.println(Arrays.toString(regulars.toArray()));
		List<Filter> filters = new ArrayList<>();
		filters.add(new BrandFilter(Brand.Apple));
		filters.add(new TypeFilter(Type.NOTEBOOK));
		List<Computer> result = FilterUtils.filter(regulars, filters);
		System.out.println("筛选后的信息");
		System.out.println(Arrays.toString(result.toArray()));
	}	
}