Java设计模式【八】：过滤器模式

public 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 name;
    }
    public String getGender() {
        return gender;
    }
    public String getMaritalStatus() {
        return maritalStatus;
    }
}

public interface Criteria {
    public List<Person> meetCriteria(List<Person> persons);
}

public class CriteriaMale implements Criteria {
    @Override
    public List<Person> meetCriteria(List<Person> persons) {
        List<Person> malePersons = new ArrayList<Person>();
        for (Person person : persons) {
            if(person.getGender().equalsIgnoreCase("MALE")){
                malePersons.add(person);
            }
        }
        return malePersons;
    }
}

public class CriteriaFemale implements Criteria {
    @Override
    public List<Person> meetCriteria(List<Person> persons) {
        List<Person> femalePersons = new ArrayList<Person>();
        for (Person person : persons) {
            if(person.getGender().equalsIgnoreCase("FEMALE")){
                femalePersons.add(person);
            }
        }
        return femalePersons;
    }
}

public class CriteriaSingle implements Criteria {
    @Override
    public List<Person> meetCriteria(List<Person> persons) {
        List<Person> singlePersons = new ArrayList<Person>();
        for (Person person : persons) {
            if(person.getMaritalStatus().equalsIgnoreCase("SINGLE")){
                singlePersons.add(person);
            }
        }
        return singlePersons;
    }
}

public class AndCriteria implements Criteria {
    private Criteria criteria;
    private Criteria otherCriteria;
    public AndCriteria(Criteria criteria, Criteria otherCriteria) {
        this.criteria = criteria;
        this.otherCriteria = otherCriteria;
    }
    @Override
    public List<Person> meetCriteria(List<Person> persons) {
        List<Person> firstCriteriaPersons = criteria.meetCriteria(persons);
        return otherCriteria.meetCriteria(firstCriteriaPersons);
    }
}

public class OrCriteria implements Criteria {
    private Criteria criteria;
    private Criteria otherCriteria;
    public OrCriteria(Criteria criteria, Criteria otherCriteria) {
        this.criteria = criteria;
        this.otherCriteria = otherCriteria;
    }
    @Override
    public List<Person> meetCriteria(List<Person> persons) {
        List<Person> firstCriteriaItems = criteria.meetCriteria(persons);
        List<Person> otherCriteriaItems = otherCriteria.meetCriteria(persons);
        for (Person person : otherCriteriaItems) {
            if(!firstCriteriaItems.contains(person)){
                firstCriteriaItems.add(person);
            }
        }
        return firstCriteriaItems;
    }
}

public class CriteriaPatternDemo {
    public static void main(String[] args) {
        List<Person> persons = new ArrayList<Person>();
        persons.add(new Person("Robert","Male", "Single"));
        persons.add(new Person("John","Male", "Married"));
        persons.add(new Person("Laura","Female", "Married"));
        persons.add(new Person("Diana","Female", "Single"));
        persons.add(new Person("Mike","Male", "Single"));
        persons.add(new Person("Bobby","Male", "Single"));
        Criteria male = new CriteriaMale();
        Criteria female = new CriteriaFemale();
        Criteria single = new CriteriaSingle();
        Criteria singleMale = new AndCriteria(single, male);
        Criteria singleOrFemale = new OrCriteria(single, female);
        System.out.println("Males: ");
        printPersons(male.meetCriteria(persons));
        System.out.println("\nFemales: ");
        printPersons(female.meetCriteria(persons));
        System.out.println("\nSingle Males: ");
        printPersons(singleMale.meetCriteria(persons));
        System.out.println("\nSingle Or Females: ");
        printPersons(singleOrFemale.meetCriteria(persons));
    }
    public static void printPersons(List<Person> persons){
        for (Person person : persons) {
            System.out.println("Person : [ Name : " + person.getName()
                    +", Gender : " + person.getGender()
                    +", Marital Status : " + person.getMaritalStatus()
                    +" ]");
        }
    }
}