A concept
Simply put, the strategy pattern is to deal with the rule changes and new rules added influence on the program brings. For object-oriented programming how to achieve it? Avoid calling rules directly through the interface, so that the change will not have an impact on business rules. At the same time, add a new rule will not affect the business processes.
Strategy Mode three roles:
● Environment (Context) role: to hold a Strategy of reference, so any particular class only need to implement the policy environment interface can be passed in the role, so that each specific policy environment will be a new role as a carrier strategy to implement different strategies .
● abstract strategy (Strategy) Role: This is an abstract role, usually implemented by an interface or abstract class. This role gives specific strategies required for all class interface.
● specific strategies (ConcreteStrategy) role: the role of inheritance or implement abstract strategy, packaging related algorithms or behavior.
II. Code three roles tender strategy mode
1. environmental role
public class Context {
//持有一个具体策略的对象
private Strategy strategy;
/**
* 构造函数，传入一个具体策略对象
* @param strategy 具体策略对象
*/
public Context(Strategy strategy){
this.strategy = strategy;
}
/**
* 策略方法
*/
public void contextInterface(){
strategy.strategyInterface();
}
}
2. abstract strategy interface class
public interface Strategy {
/**
* 策略方法
*/
public void strategyInterface();
}3. A concrete strategy class
public class ConcreteStrategyA implements Strategy {
@Override
public void strategyInterface() {
//相关的业务
}
}
4. DETAILED Strategy B
public class ConcreteStrategyB implements Strategy {
@Override
public void strategyInterface() {
//相关的业务
}
}
5. Test Class
public class TestStratege {
public static void main (String[] args) {
ConcreteStrategyA concreteStrategyA = new ConcreteStrategyA();
Context contextA = new Context (concreteStrategyA);
contextA .contextInterface();
ConcreteStrategyB concreteStrategyB = new ConcreteStrategyB();
Context contextB = new Context (concreteStrategyB);
contextB .contextInterface();
}
}III. Combat scenarios
Necessary to manufacture a number of existing parking, outpatient, visitors, hotel data, need to go through data acquisition, package, pushed rabbitmq of three processes.
1. Environmental role prepared (as a thread class, each data type corresponds to one thread environment)
public class DispatchThread<T> implements Runnable {
private DataHandle<T> dataHandle;
private RabbitMqParams params;
public DispatchThread(DataHandle<T> dataHandle, RabbitMqParams params){
this.dataHandle=dataHandle;
this.params=params;
}
@Override
public void run() {
T t;
while (true){
try {
t= dataHandle.getData();
t = dataHandle.format(t);
dataHandle.sendData(params,t);
Thread.sleep(20*1000);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
2. Strategy ---- abstract strategy interfaces (providing access to data, packaging data and push data interface templates)
public interface DataHandle<T> {
T getData();
T format(T t);
void sendData(RabbitMqParams params,T t);
}
3. Specific Strategy Implementation Strategy ---- Interface
(1) Parking Strategy Implementation Strategy --- Interface
public class PicParkDataHandle implements DataHandle<PicPark> {
private static final Logger logger = Logger.getLogger(PicParkDataHandle.class);
@Override
public PicPark getData() {
String json = "xxxxx";
PicPark picPark = JSON.parseObject(json, PicPark.class);
return picPark;
}
@Override
public PicPark format(PicPark picPark) {
picPark.setAreaName(picPark.getAreaName()+System.currentTimeMillis());
picPark.setCapTime(System.currentTimeMillis());
picPark.setCreateTime(System.currentTimeMillis());
picPark.setObjId(RandomPlateUtil.generateCarID());
picPark.setPlateNum(picPark.getObjId());
picPark.setRecordId(UUID.randomUUID().toString().replace("-",""));
return picPark;
}
@Override
public void sendData(RabbitMqParams params,PicPark picPark) {
RabbitProductClient client=new RabbitProductClient(params.getExchangName(),params.getHost(),params.getPort(),params.getUsername(),params.getPassword(),params.getExchangeType());
try {
client.sendMessage(JSON.toJSONString(picPark),params.getRouteKey());
logger.info("停车场数据发送成功： " + JSON.toJSONString(picPark));
} catch (Exception e) {
logger.error("发送停车场数据出错");
e.printStackTrace();
}
}
}
(2) ----- class hotel policy implementation strategies Interface
public class HotelHandle implements DataHandle<Hotel> {
private static final Logger logger = Logger.getLogger(HotelHandle.class);
@Override
public Hotel getData() {
Hotel hotel=new Hotel();
hotel.setBirthday("1995-10-20");
hotel.setCapTime(System.currentTimeMillis());
hotel.setCardNo(IdCardGenerator.generate());
hotel.setCreateTime(System.currentTimeMillis());
hotel.setInTime(System.currentTimeMillis());
hotel.setLeaveTime(System.currentTimeMillis());
hotel.setName(NameGenerator.build());
hotel.setNation("汉族");
hotel.setNativePlace(RandomValue.getRoad());
hotel.setOutTime(System.currentTimeMillis());
hotel.setRoomno("304");
hotel.setSex("女");
return hotel;
}
@Override
public Hotel format(Hotel hotel) {
return hotel;
}
@Override
public void sendData(RabbitMqParams params, Hotel hotel) {
RabbitProductClient client=new RabbitProductClient(params.getExchangName(),params.getHost(),params.getPort(),params.getUsername(),params.getPassword(),params.getExchangeType());
try {
client.sendMessage(JSON.toJSONString(hotel),params.getRouteKey());
logger.info("旅馆数据发送成功： " + JSON.toJSONString(hotel));
} catch (Exception e) {
logger.error("发送旅馆数据出错");
e.printStackTrace();
}
}
}
4. Use environment different specific roles Strategy load (environmental load different roles thread real policy role of different types of data acquisition is completed, the package, pushed)
@Component
public class ProcessStarter implements ApplicationRunner {
@Override
public void run(ApplicationArguments args) throws Exception {
logger.info("模拟数据启动O(∩_∩)O~O(∩_∩)O~O(∩_∩)O~O(∩_∩)O~O(∩_∩)O~");
try {
//停车场数据
if (true) {
logger.info("picPark data product O(∩_∩)O~");
PicParkDataHandle handle=new PicParkDataHandle();
RabbitMqParams params=new RabbitMqParams();
params.rabbitInit();
params.setExchangName("xx_xx");
params.setRouteKey("xx.xx.2.*");
DispatchThread<PicPark> dispatchThread=new DispatchThread(handle,params);
Thread picThread = new Thread(dispatchThread);
picThread.setName("PicParkThread");
picThread.start();
ThreadMonitor.getInstance().addThreadMonitor(picThread);
}
if (true) {
logger.info("hotel data product O(∩_∩)O~");
HotelHandle handle=new HotelHandle();
RabbitMqParams params=new RabbitMqParams();
params.rabbitInit();
params.setExchangName("xx_xx");
params.setRouteKey("xx.xx.2");
DispatchThread<Hotel> dispatchThread=new DispatchThread(handle,params);
Thread hotelThread = new Thread(dispatchThread);
hotelThread.setName("HotelThread");
hotelThread.start();
ThreadMonitor.getInstance().addThreadMonitor(hotelThread);
}
logger.info("模拟数据启动程序启动完成//(≧▽≦)//~~//(≧▽≦)//~~//(≧▽≦)//~");
} catch (Exception e) {
logger.error("模拟数据启动程序启动时发生异常(╯﹏╰）(╯﹏╰）"+e.getMessage(),e);
}
}
}
