Esper事件处理引擎_2_Map 数据结构处理

Map 数据结构处理

package com.framework_technology.esper.event_type;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.espertech.esper.client.*;

/**
* Created by IntelliJ IDEA.
* User: wei.Li
* Date: 14-7-28
* Time: 16:27
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Esper支持原生Java Map结构的事件。相对于POJO来说，Map的结构更利于事件类型的热加载，毕竟不是class，所以不需要重启JVM。
* 所以如果系统对重启比较敏感，建议使用Map来定义事件的结构。Map的结构很简单，主要分为事件定义名和事件属性列表。
* <p>
* 1.Person在定义Address属性时，map的value不是Address.class，而是Address字符串，而这就代表引擎里的Address对应的Map结构定义
* 2.事件定义注册必须是Address先于Person，因为Person用到了Address，而引擎是根据Address注册时用的名字去查找Address定义的，所以如果名字写错，引擎就找不到Address了
* 如果Person有多个Address，则以数组方式定义Person的多个Address时，代码又变成下面的样子了
* person.put("addresses", "Address[]");
* <p>
* 目标： 当Person类型的事件中name为luonanqin时，Esper能得到对应的age,children
* TODO PropertyAccessException : Property named 'address' is not a valid property name for this type
*/
public class Map_EventType {
static EPServiceProvider defaultProvider = EPServiceProviderManager.getDefaultProvider();
static EPAdministrator epAdministrator = defaultProvider.getEPAdministrator();

public static void main(String[] args) {

// Address定义
Map<String, Object> address = new HashMap<String, Object>();
address.put("road", String.class);
address.put("street", String.class);
address.put("houseNo", int.class);

// Person定义
Map<String, Object> person = new HashMap<String, Object>();
person.put("name", String.class);
person.put("age", int.class);
person.put("children", List.class);
person.put("phones", Map.class);
person.put("address", "Address");

// 注册Address到Esper
epAdministrator.getConfiguration().addEventType("Address", address);
// 注册Person到Esper
epAdministrator.getConfiguration().addEventType("Person", person);

/**
* 另外对于Map，Esper只支持增量更新，也就是说只能增加Map中的属性定义，
* 而不能修改或者删除某个属性（实际上属性增多并不影响其处理性能，所以没有删除在我看来也没什么。至于修改，也只能是先注销再注册了）。
* 我们为Person增加一个sex属性
*/
person.put("sex", int.class);
epAdministrator.getConfiguration().updateMapEventType("Person", person);

/** 输出结果：
* Person props: [address, age, name, children, phones, gender]
*/
EventType person_EventType = epAdministrator.getConfiguration().getEventType("Person");
System.out.println("Person  props: " + Arrays.asList(person_EventType.getPropertyNames()));
EventType address_EventType = epAdministrator.getConfiguration().getEventType("Address");
System.out.println("Address props: " + Arrays.asList(address_EventType.getPropertyNames()));

//目标： 当Person类型的事件中name为luonanqin时，Esper能得到对应的age,children
String epl = "select age,children from Person where name=\"xiaohulu\"";
EPStatement epStatement = epAdministrator.createEPL(epl);
//注册修改事件监听
epStatement.addListener((newEvents, oldEvents) -> {
if (newEvents != null) {
System.out.println("~~~~~~~~~~~~~newEvents write~~~~~~~~~~~~~~");
System.out.println("Person's age        is \t" + newEvents[0].get("age"));
System.out.println("Person's children   is \t" + newEvents[0].get("children"));
System.out.println("Person's address    is \t" + newEvents[0].get("address"));
}
});
final EPRuntime epRuntime = defaultProvider.getEPRuntime();

Map<String, Object> addressMap = new HashMap<String, Object>();
addressMap.put("road", "BeiJing.100");
Map<String, Object> personMap = new HashMap<String, Object>();
personMap.put("name", "xiaohulu");
personMap.put("address", addressMap);

epRuntime.sendEvent(personMap, "Person");
}
}