责任链模式

顾名思义，责任链模式（Chain of Responsibility Pattern）为请求创建了一个接收者对象的链。这种模式给予请求的类型，对请求的发送者和接收者进行解耦。这种类型的设计模式属于行为型模式。

在这种模式中，通常每个接收者都包含对另一个接收者的引用。如果一个对象不能处理该请求，那么它会把相同的请求传给下一个接收者，依此类推。

类图

Student类

class Student{  
  
    private String name;  
    private String sex;  
  
    public Student(String name, String sex) {  
        this.name = name;  
        this.sex = sex;  
    }  
  
    public String getName() {  
        return name;  
    }  
    public void setName(String name) {  
        this.name = name;  
    }  
    public String getSex() {  
        return sex;  
    }  
    public void setSex(String sex) {  
        this.sex = sex;  
    }  
  
}  

过滤抽象类

/**  
 * 自定义抽象过滤器类  
 * @param <T1> 过滤对象类型  
 * @param <T2> 过滤属性类型  
 */
abstract class AbstractFilter<T1,T2> {  
    List<T2> filterValues;  
    AbstractFilter<T1,T2> nextFilter;  
  
    AbstractFilter(List<T2> filterValues) {  
        this.filterValues = filterValues;  
    }  
    public void setNextFilter(AbstractFilter<T1,T2> filter) {  
        nextFilter = filter;  
    }  
  
    abstract void doFilter(List<T1> source);  
}  

名字过滤类

class NameFilter extends AbstractFilter<Student,String> {  
  
    NameFilter(List<String> filterValues) {  
        super(filterValues);  
    }  
    @Override  
    void doFilter(List<Student> list) {  
        list.removeIf(s -> filterValues.contains(s.getName()));  
        if (nextFilter != null) {  
            nextFilter.doFilter(list);  
        }  
    }  
}  
 

性别过滤类

class SexFilter extends AbstractFilter<Student,String> {  
  
    SexFilter(List<String> filterValues) {  
        super(filterValues);  
    }  
  
    @Override  
    void doFilter(List<Student> list) {  
        list.removeIf(s -> filterValues.contains(s.getSex()));  
        if (nextFilter != null) {  
            nextFilter.doFilter(list);  
        }  
    }  
}  

测试

public class Main {  
    public static void main(String[] args) {  
        Student xiaowang=new Student("xiaowang","man");  
        Student xiaoliu=new Student("xiaoliu","women");  
        Student xiaozhang=new Student("xiaozhang","man");  
  
        List<Student> studentList = new ArrayList<>();  
        studentList.add(xiaoliu);  
        studentList.add(xiaowang);  
        studentList.add(xiaozhang);  
  
        // 过滤xiaoliu  
        NameFilter nameFilter = new NameFilter(Arrays.asList("xiaoliu"));  
        // 过滤women  
        SexFilter sexFilter = new SexFilter(Arrays.asList("women"));  
        // 设置name的下一个过滤器  
        nameFilter.setNextFilter(sexFilter);  
  
        // 开始过滤  
        nameFilter.doFilter(studentList);  
  
        studentList.stream().forEach(stu-> System.out.println(stu.getName()+" "+stu.getSex()));  
    }  
}