徒手撸设计模式-过滤器模式
作者：互联网
概念
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。
参考链接: https://www.runoob.com/design-pattern/filter-pattern.html
代码案例
公共类
public final class StFlag {
public StFlag() {
}
/**
* 汽车
*/
public static final String CAR="CAR";
/**
* 自行车
*/
public static final String BICYCLE="BICYCLE";
/**
* 蓝色
*/
public static final String BLUE="BLUE";
/**
* 交通工具类型-宝马
*/
public static final String TRANSPORT_TYPE_BMW="BMW";
/**
* 交通工具类型-奔驰
*/
public static final String TRANSPORT_TYPE_BENZ="BENZ";
/**
* 交通工具类型-捷安特
*/
public static final String TRANSPORT_TYPE_GIANT="GIANT";
/**
* 交通工具类型-美利达
*/
public static final String TRANSPORT_TYPE_MERIDA="MERIDA";
}
写一个实体类,有三个属性
/**
* 交通工具实体类
*/
@Getter
@AllArgsConstructor
@Setter
@ToString
public class Transport {
private String name;
private String type;
private String colour;
}
写一个接口,用于过滤匹配的数据
public interface Match {
public List<Transport> getMatches(List<Transport> transports);
}
五个实现类
/**
* 自行车匹配实现类
*/
public class BicycleMatch implements Match {
@Override
public List<Transport> getMatches(List<Transport> transports) {
List<Transport> transportsBicycle = new ArrayList<>();
for (Transport transport : transports) {
if (transport.getType().equalsIgnoreCase(StFlag.BICYCLE)) {
transportsBicycle.add(transport);
}
}
return transportsBicycle;
}
}
/**
* 汽车匹配实现类
*/
public class CarMatch implements Match {
@Override
public List<Transport> getMatches(List<Transport> transports) {
List<Transport> transportsCar = new ArrayList<>();
for (Transport transport : transports) {
if (transport.getType().equalsIgnoreCase(StFlag.CAR)) {
transportsCar.add(transport);
}
}
return transportsCar;
}
}
/**
* 颜色匹配实现类
*/
public class BlueMatch implements Match {
@Override
public List<Transport> getMatches(List<Transport> transports) {
List<Transport> transportsBlue = new ArrayList<>();
for (Transport transport : transports) {
if (transport.getColour().equalsIgnoreCase(StFlag.BLUE)) {
transportsBlue.add(transport);
}
}
return transportsBlue;
}
}
/**
* 且运算
*/
public class AndMatch implements Match {
private Match bicycleMatch;
private Match blueMatch;
public AndMatch(Match bicycleMatch, Match blueMatch) {
this.bicycleMatch = bicycleMatch;
this.blueMatch = blueMatch;
}
@Override
public List<Transport> getMatches(List<Transport> transports) {
List<Transport> cars = blueMatch.getMatches(transports);
return bicycleMatch.getMatches(cars);
}
}
/**
* 或运算
*/
public class OrMatch implements Match {
private Match bicycleMatch;
private Match carMatch;
public OrMatch(Match bicycleMatch, Match carMatch) {
this.bicycleMatch = bicycleMatch;
this.carMatch = carMatch;
}
@Override
public List<Transport> getMatches(List<Transport> transports) {
List<Transport> cars = carMatch.getMatches(transports);
List<Transport> bicycles = bicycleMatch.getMatches(transports);
for (Transport car : cars) {
if (!bicycles.contains(car)){
bicycles.add(car);
}
}
return bicycles;
}
}
测试主类
/**
* 设计模式控制器
*/
@RestController
@RequestMapping("/designPattern")
@Slf4j
public class DesignController {
@PostMapping("/filter")
public ResponseModel filter(@RequestBody List<Transport> transports) {
log.info("DesignController--- filter --start--");
Match carMatch = new CarMatch();
Match blueMatch = new BlueMatch();
BicycleMatch bicycleMatch = new BicycleMatch();
Match andMatch = new AndMatch(bicycleMatch,blueMatch);
Match orMatch = new OrMatch(bicycleMatch, carMatch);
List<Transport> carList = carMatch.getMatches(transports);
List<Transport> blueList = blueMatch.getMatches(transports);
List<Transport> bicycleList = bicycleMatch.getMatches(transports);
List<Transport> andList = andMatch.getMatches(transports);
List<Transport> orList = orMatch.getMatches(transports);
Map<String, List> result= new HashMap<>();
result.put("carList",carList);
result.put("blueList",blueList);
result.put("bicycleList",bicycleList);
result.put("andList",andList);
result.put("orList",orList);
log.info("DesignController--- filter --end--");
log.info("result is : {}", JSON.toJSONString(result,true));
return new ResponseModel("过滤器模式完成", 200, result);
}
}
测试案例
控制台日志
2022-06-22 01:27:43.211 INFO DesignController--- filter --start-- 【http-nio-8081-exec-2】【DesignController:60】
2022-06-22 01:27:43.214 INFO DesignController--- filter --end-- 【http-nio-8081-exec-2】【DesignController:78】
2022-06-22 01:27:43.222 INFO result is : {
"andList":[
{
"colour":"blue",
"name":"giant",
"type":"bicycle"
},
{
"colour":"blue",
"name":"feige",
"type":"bicycle"
}
],
"bicycleList":[
{"$ref":"$.andList[0]"},
{"$ref":"$.andList[1]"},
{
"colour":"write",
"name":"fenghuang",
"type":"bicycle"
}
],
"orList":[
{"$ref":"$.andList[0]"},
{"$ref":"$.andList[1]"},
{"$ref":"$.bicycleList[2]"},
{
"colour":"blue",
"name":"bmw",
"type":"car"
},
{
"colour":"yellow",
"name":"benz",
"type":"car"
},
{
"colour":"blue",
"name":"poche",
"type":"car"
}
],
"blueList":[
{"$ref":"$.orList[3]"},
{"$ref":"$.andList[0]"},
{"$ref":"$.andList[1]"},
{"$ref":"$.orList[5]"}
],
"carList":[
{"$ref":"$.orList[3]"},
{"$ref":"$.orList[4]"},
{"$ref":"$.orList[5]"}
]
} 【http-nio-8081-exec-2】【DesignController:79】
标签：bicycleMatch,List,过滤器,getMatches,设计模式,transports,public,Match,徒手 来源： https://www.cnblogs.com/hikoukay/p/16399026.html