过滤器模式

过滤器模式(Filter Pattern)或标准模式(Criteria Pattern)是一种设计模式,这种模式允许开发人员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。这种类型的设计模式属于结构型模式,它结合多个标准来获得单一标准。

 

创建一个过滤人性别的过滤器模式

创建person对象

public class Person {
    private String name;
    private String gender;//xingbie

    public Person(String name,String gender){
      this.name = name;
      this.gender = gender;
    }

    public String getName() {
      return name;
    }
    public String getGender() {
      return gender;
    }
}

创建标准接口  Criteria 

public interface Criteria {

  public List<Person> meetCriteria(List<Person> persons);
}

创建man和women类实现Criteria接口

public class man implements Criteria{

@Override
public List<Person> meetCriteria(List<Person> persons) {
    List<Person> list = new ArrayList<>();
    for (Person person : persons) {
      if(person.getGender().equalsIgnoreCase("man")){
        list.add(person);
      }
    }
    return list;
  }

}

 

public class women implements Criteria{

@Override
public List<Person> meetCriteria(List<Person> persons) {
    List<Person> list = new ArrayList<>();
    for (Person person : persons) {
      if(person.getGender().equalsIgnoreCase("women")){
        list.add(person);
      }
    }
    return list;
  }

}

创建and和or两种过滤Criteria

public class and implements Criteria{

    private Criteria criteria;
    private Criteria othercriteria;

    public and(Criteria criteria, Criteria othercriteria) {
      super();
      this.criteria = criteria;
      this.othercriteria = othercriteria;
    }

 

    @Override
    public List<Person> meetCriteria(List<Person> persons) {
      List<Person> list1 = criteria.meetCriteria(persons);
      return othercriteria.meetCriteria(list1);
    }

}

 

public class or  implements Criteria{

    private Criteria criteria;
    private Criteria othercriteria;

    public and(Criteria criteria, Criteria othercriteria) {
      super();
      this.criteria = criteria;
      this.othercriteria = othercriteria;
    }

 

    @Override
    public List<Person> meetCriteria(List<Person> persons) {

      List<Person> list1 = Criteria.meetCriteria(persons);
      List<Person> meetCriteria = otherCriteria.meetCriteria(persons);
      for (Person person : meetCriteria) {
        if (!list1.contains(person)) {
          list1.add(person);
        }
      }
    return list1;

    }

}

main测试 

    public static void main(String[] args) {
      List<Person> persons = new ArrayList<Person>();

      persons.add(new Person("Robert","man"));
      persons.add(new Person("John","man"));
      persons.add(new Person("Laura","women"));
      persons.add(new Person("Diana","women"));
      persons.add(new Person("Mike","man"));
      persons.add(new Person("Bobby","man"));

      Criteria male = new man();//男的
      Criteria female = new women();//女的
      Criteria singleMale = new and(female, male);//既是男的也是女的
      Criteria singleOrFemale = new or(male, female);//是男的或是女的

      System.out.println("man: ");
      printPersons(male.meetCriteria(persons));

      System.out.println("\\women: ");
      printPersons(female.meetCriteria(persons));

      System.out.println("\\and: ");
      printPersons(singleMale.meetCriteria(persons));

      System.out.println("\\Or: ");
      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()
      +" ]");
    }
}

 

posted @ 2017-06-02 10:49  小熊是个随便的人  阅读(185)  评论(0编辑  收藏  举报