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Java 过滤器模式

2022年07月19日48zfyouxi

1.过滤器模式简介
过滤器模式(Filter Pattern)又称标准模式(Criteria Pattern),用于使用不同的标准来过滤一组对象,通过逻辑运算以解耦的方式把它们连接起来。属于结构型模式,它结合多个标准来获得单一标准。

2.测试Demo

import java.util.List; 
import java.util.ArrayList; 
 
class Person { 
    private String name; 
    private String gender; 
    private String maritalStatus; 
 
    public Person(String name, String gender, String maritalStatus) { 
        this.name = name; 
        this.gender = gender; 
        this.maritalStatus = maritalStatus; 
    } 
 
    public String getName() { 
        return this.name; 
    } 
    public String getGender() { 
        return this.gender; 
    } 
    public String getMaritalStatus() { 
        return this.maritalStatus; 
    } 
} 
 
 
interface Criteria { 
    public List<Person> meetCriteria(List<Person> persons); 
} 
 
class MaleCtiteria implements Criteria { 
    @Override 
    public List<Person> meetCriteria(List<Person> persons) { 
        List<Person> maleMeet = new ArrayList<Person>(); 
        for (Person person : persons) { 
            if (person.getGender().equalsIgnoreCase("MALE")) { 
                maleMeet.add(person); 
            } 
        } 
        return maleMeet; 
    } 
} 
 
class FemaleCtiteria implements Criteria { 
    @Override 
    public List<Person> meetCriteria(List<Person> persons) { 
        List<Person> femaleMeet = new ArrayList<Person>(); 
        for (Person person : persons) { 
            if (person.getGender().equalsIgnoreCase("FEMALE")) { 
                femaleMeet.add(person); 
            } 
        } 
        return femaleMeet; 
    } 
} 
 
 
class SingleCtiteria implements Criteria { 
    @Override 
    public List<Person> meetCriteria(List<Person> persons) { 
        List<Person> singleMeet = new ArrayList<Person>(); 
        for (Person person : persons) { 
            if (person.getMaritalStatus().equalsIgnoreCase("Single")) { 
                singleMeet.add(person); 
            } 
        } 
        return singleMeet; 
    } 
} 
 
 
class AndCtiteria implements Criteria { 
    private Criteria meetCriteria1; 
    private Criteria meetCriteria2; 
 
    public AndCtiteria(Criteria meetCriteria1, Criteria meetCriteria2) { 
        this.meetCriteria1 = meetCriteria1; 
        this.meetCriteria2 = meetCriteria2; 
    } 
 
    @Override 
    public List<Person> meetCriteria(List<Person> persons) { 
        List<Person> andMeet = meetCriteria1.meetCriteria(persons); 
        andMeet = meetCriteria2.meetCriteria(andMeet); 
 
        return andMeet; 
    } 
} 
 
 
class OrCtiteria implements Criteria { 
    private Criteria selectCriteria1; 
    private Criteria selectCriteria2; 
 
    public OrCtiteria(Criteria selectCriteria1, Criteria selectCriteria2) { 
        this.selectCriteria1 = selectCriteria1; 
        this.selectCriteria2 = selectCriteria2; 
    } 
 
    @Override 
    public List<Person> meetCriteria(List<Person> persons) { 
        List<Person> selectMeet1 = selectCriteria1.meetCriteria(persons); 
        List<Person> selectMeet2 = selectCriteria2.meetCriteria(persons); 
 
        for (Person person : selectMeet1) { 
            if (!selectMeet2.contains(person)) { 
                selectMeet2.add(person); 
            } 
        } 
 
        return selectMeet2; 
    } 
} 
 
 
 
public class MeteriaPatternDemo { 
    public static void main(String args[]) { 
        List<Person> persons = new ArrayList<Person>(); 
        persons.add(new Person("Jane", "MALE", "Single")); 
        persons.add(new Person("July", "FEMALE", "Married")); 
        persons.add(new Person("Kitty", "MALE", "Married")); 
        persons.add(new Person("James", "FEMALE", "Single")); 
 
        Criteria maleCriteria = new MaleCtiteria(); 
        Criteria singleCriteria = new SingleCtiteria(); 
        Criteria andCriteria = new AndCtiteria(maleCriteria, singleCriteria); 
        Criteria orCriteria = new OrCtiteria(maleCriteria, singleCriteria); 
 
        System.out.println("Male:"); 
        PrintPerson(maleCriteria.meetCriteria(persons)); 
 
        System.out.println("Single:"); 
        PrintPerson(singleCriteria.meetCriteria(persons)); 
 
        System.out.println("Male and Single:"); 
        PrintPerson(andCriteria.meetCriteria(persons)); 
 
        System.out.println("Male or Single:"); 
        PrintPerson(orCriteria.meetCriteria(persons)); 
    } 
 
 
    public static void PrintPerson(List<Person> persons) { 
        for (Person person : persons) { 
            System.out.println("name=" + person.getName() + "  " + "gender=" + person.getGender() + "  " + "maritalStatus=" + person.getMaritalStatus());         
        } 
    } 
}

参考:http://www.runoob.com/design-pattern/filter-pattern.html


本文参考链接:https://www.cnblogs.com/hellokitty2/p/10688867.html