过滤器模式 rust和java的实现
文章目录
- 过滤器模式
-
-
- 实现
-
- 过滤器模式
-
-
- 实现
- java
- rust
- java
- rust
- rust代码仓库
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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。
实现
我们将创建一个 Person 对象、Criteria 接口和实现了该接口的实体类，来过滤 Person 对象的列表。CriteriaPatternDemo 类使用 Criteria 对象，基于各种标准和它们的结合来过滤 Person 对象的列表。
我们制作一个Person实体类，Criteria为标准条件，CriteriaMale等为实现的具体判断器，是需要为person类使用meetCriteria方法便可以进行不同条件的判断。
过滤器模式的 UML 图
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。
实现
我们将创建一个 Person 对象、Criteria 接口和实现了该接口的实体类，来过滤 Person 对象的列表。CriteriaPatternDemo 类使用 Criteria 对象，基于各种标准和它们的结合来过滤 Person 对象的列表。
我们制作一个Person实体类，Criteria为标准条件，CriteriaMale等为实现的具体判断器，是需要为person类使用meetCriteria方法便可以进行不同条件的判断。
过滤器模式的 UML 图
java
步骤 1
创建一个类，在该类上应用标准。
Person.java
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;
}
}
步骤 2
为标准（Criteria）创建一个接口。
Criteria.java
import java.util.List;
public interface Criteria {
public List<Person> meetCriteria(List<Person> persons);
}
步骤 3
创建实现了 Criteria 接口的实体类。
CriteriaMale.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
CriteriaFemale.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
CriteriaSingle.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
AndCriteria.java
import java.util.List;
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);
}
}
OrCriteria.java
import java.util.List;
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;
}
}
步骤4
使用不同的标准（Criteria）和它们的结合来过滤 Person 对象的列表。
CriteriaPatternDemo.java
import java.util.ArrayList;
import java.util.List;
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()
+" ]");
}
}
}
步骤 5
执行程序，输出结果：
Males:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : John, Gender : Male, Marital Status : Married ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Females:
Person : [ Name : Laura, Gender : Female, Marital Status : Married ]
Person : [ Name : Diana, Gender : Female, Marital Status : Single ]
Single Males:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Single Or Females:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : Diana, Gender : Female, Marital Status : Single ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Person : [ Name : Laura, Gender : Female, Marital Status : Married ]
rust
由于时间关系，并没有实现or条件，大家有兴趣可以自行补充
// 设置人类实体类
#[derive(Clone)]
struct Person{
name:String,
gender:String,
marital_status:String
}
impl Person {
fn get_gender(&self)->&str {
self.gender.as_ref()
}
fn get_marital_status(&self)->&str {
self.marital_status.as_ref()
}
}
// 设置过滤标准特征
trait Criteria {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>;
}
// 设置男性
struct CriteriaMale{}
// 重写男性评判标准
impl Criteria for CriteriaMale {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_gender().eq_ignore_ascii_case("MALE")).collect()
}
}
// 设置女性
struct CriteriaFemale{}
// 设置女性标准
impl Criteria for CriteriaFemale{
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_gender().eq_ignore_ascii_case("FEMALE")).collect()
}
}
// 设置单身标准
struct CriteriaSingle{}
impl Criteria for CriteriaSingle{
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_marital_status().eq_ignore_ascii_case("SINGLE")).collect()
}
}
// 设置and标准，求交集
struct AndCriteria {
criteria:Box<dyn Criteria>,
other_criteria:Box<dyn Criteria>
}
impl Criteria for AndCriteria {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person> {
self.other_criteria.meet_criteria(self.criteria.meet_criteria(persons))
}
}
// struct OrCriteria {
// criteria:Box,
// other_criteria:Box)->Vec {
// let mut first_criteria_items = self.criteria.meet_criteria(persons);
// let other_criteria_items = self.other_criteria.meet_criteria(persons);
// for o in other_criteria_items {
// if !other_criteria_items.contains(&o) {
// first_criteria_items.push(o);
// }
// }
// first_criteria_items
// }
// }
fn print_persons(persons:Vec<Person>) {
persons.into_iter().for_each(|x| println!("Person : [NAME: {},Gender : {} ,Maeital Status : {} ]",x.name,x.gender,x.marital_status));
}
fn main() {
let mut persons=Vec::new();
persons.push(Person{name:String::from("Robert"),gender:String::from("Male"),marital_status:String::from("Single")});
persons.push(Person{name:String::from("John"),gender:String::from("Male"),marital_status:String::from("Married")});
persons.push(Person{name:String::from("Laura"),gender:String::from("Female"),marital_status:String::from("Married")});
persons.push(Person{name:String::from("Diana"),gender:String::from("Female"),marital_status:String::from("Single")});
let male=Box::new(CriteriaMale{});
let female=Box::new(CriteriaFemale{});
let single_male=AndCriteria{criteria:Box::new(CriteriaSingle{}),other_criteria:Box::new(CriteriaMale{})};
// let single_or_female=OrCriteria{criteria:Box::new(CriteriaMale{}),other_criteria:Box::new(CriteriaFemale{})};
println!("男士");
print_persons(male.meet_criteria(persons.clone()));
println!("女士");
print_persons(female.meet_criteria(persons.clone()));
println!("单身男士");
print_persons(single_male.meet_criteria(persons))
}
java
步骤 1
创建一个类，在该类上应用标准。
Person.java
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;
}
}
步骤 2
为标准（Criteria）创建一个接口。
Criteria.java
import java.util.List;
public interface Criteria {
public List<Person> meetCriteria(List<Person> persons);
}
步骤 3
创建实现了 Criteria 接口的实体类。
CriteriaMale.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
CriteriaFemale.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
CriteriaSingle.java
import java.util.ArrayList;
import java.util.List;
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;
}
}
AndCriteria.java
import java.util.List;
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);
}
}
OrCriteria.java
import java.util.List;
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;
}
}
步骤4
使用不同的标准（Criteria）和它们的结合来过滤 Person 对象的列表。
CriteriaPatternDemo.java
import java.util.ArrayList;
import java.util.List;
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()
+" ]");
}
}
}
步骤 5
执行程序，输出结果：
Males:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : John, Gender : Male, Marital Status : Married ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Females:
Person : [ Name : Laura, Gender : Female, Marital Status : Married ]
Person : [ Name : Diana, Gender : Female, Marital Status : Single ]
Single Males:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Single Or Females:
Person : [ Name : Robert, Gender : Male, Marital Status : Single ]
Person : [ Name : Diana, Gender : Female, Marital Status : Single ]
Person : [ Name : Mike, Gender : Male, Marital Status : Single ]
Person : [ Name : Bobby, Gender : Male, Marital Status : Single ]
Person : [ Name : Laura, Gender : Female, Marital Status : Married ]
rust
由于时间关系，并没有实现or条件，大家有兴趣可以自行补充
// 设置人类实体类
#[derive(Clone)]
struct Person{
name:String,
gender:String,
marital_status:String
}
impl Person {
fn get_gender(&self)->&str {
self.gender.as_ref()
}
fn get_marital_status(&self)->&str {
self.marital_status.as_ref()
}
}
// 设置过滤标准特征
trait Criteria {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>;
}
// 设置男性
struct CriteriaMale{}
// 重写男性评判标准
impl Criteria for CriteriaMale {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_gender().eq_ignore_ascii_case("MALE")).collect()
}
}
// 设置女性
struct CriteriaFemale{}
// 设置女性标准
impl Criteria for CriteriaFemale{
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_gender().eq_ignore_ascii_case("FEMALE")).collect()
}
}
// 设置单身标准
struct CriteriaSingle{}
impl Criteria for CriteriaSingle{
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person>{
persons.into_iter().filter(|x| x.get_marital_status().eq_ignore_ascii_case("SINGLE")).collect()
}
}
// 设置and标准，求交集
struct AndCriteria {
criteria:Box<dyn Criteria>,
other_criteria:Box<dyn Criteria>
}
impl Criteria for AndCriteria {
fn meet_criteria(&self,persons:Vec<Person>)->Vec<Person> {
self.other_criteria.meet_criteria(self.criteria.meet_criteria(persons))
}
}
// struct OrCriteria {
// criteria:Box,
// other_criteria:Box)->Vec {
// let mut first_criteria_items = self.criteria.meet_criteria(persons);
// let other_criteria_items = self.other_criteria.meet_criteria(persons);
// for o in other_criteria_items {
// if !other_criteria_items.contains(&o) {
// first_criteria_items.push(o);
// }
// }
// first_criteria_items
// }
// }
fn print_persons(persons:Vec<Person>) {
persons.into_iter().for_each(|x| println!("Person : [NAME: {},Gender : {} ,Maeital Status : {} ]",x.name,x.gender,x.marital_status));
}
fn main() {
let mut persons=Vec::new();
persons.push(Person{name:String::from("Robert"),gender:String::from("Male"),marital_status:String::from("Single")});
persons.push(Person{name:String::from("John"),gender:String::from("Male"),marital_status:String::from("Married")});
persons.push(Person{name:String::from("Laura"),gender:String::from("Female"),marital_status:String::from("Married")});
persons.push(Person{name:String::from("Diana"),gender:String::from("Female"),marital_status:String::from("Single")});
let male=Box::new(CriteriaMale{});
let female=Box::new(CriteriaFemale{});
let single_male=AndCriteria{criteria:Box::new(CriteriaSingle{}),other_criteria:Box::new(CriteriaMale{})};
// let single_or_female=OrCriteria{criteria:Box::new(CriteriaMale{}),other_criteria:Box::new(CriteriaFemale{})};
println!("男士");
print_persons(male.meet_criteria(persons.clone()));
println!("女士");
print_persons(female.meet_criteria(persons.clone()));
println!("单身男士");
print_persons(single_male.meet_criteria(persons))
}
rust代码仓库
https://github.com/onenewcode/design.git
本教程项目在bin文件夹下的filtert.rs文件中