首页 > > 程序设计 > Java技术 >

【转】Dubbo声明式缓存

2018-06-18 01:56:47来源：未知阅读 ()

缓存的应用非常广泛，为了提高数据访问的速度。Dubbo也不例外，它提供了声明式缓存，以减少用户加缓存的工作量。

一、Dubbo中缓存策略

二、Provider

服务端包含接口和实现

接口：

[java] view plain copy

实现：

[java] view plain copy

spring配置文件：CacheProvider.xml

[html] view plain copy

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd
">
<dubbo:application name="cache-provider" />
<dubbo:registry protocol="zookeeper" address="192.168.24.140:2181" />
<dubbo:protocol name="dubbo" port="20880" />
<dubbo:service interface="com.tgb.cacheService.CacheService" ref="cacheService" />
<bean id="cacheService" class="com.tgb.cacheService.CacheServiceImpl" />
</beans>

程序入口：

[java] view plain copy

package com.tgb.main;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* 服务端入口
* @author xx
*
*/
public class CacheProvider {
public static void main(String[] args) throws Exception{
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] { "CacheProvider.xml" });
context.start();
System.out.println("按任意键退出");
System.in.read();
}
}

三、Consumer

接口同服务端

spring配置文件：CacheConsumer.xml，配置缓存

[html] view plain copy

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd
">
<dubbo:application name="cache-consumer" />
<dubbo:registry protocol="zookeeper" address="192.168.24.140:2181" />
<dubbo:reference id="cacheService" interface="com.tgb.cacheService.CacheService" cache="true" />
</beans>

程序入口:

[html] view plain copy

package com.tgb.main;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tgb.cacheService.CacheService;
/**
* 客户端入口
* @author xx
*
*/
public class CacheConsumer {
public static void main(String[] args) throws Exception {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] { "CacheConsumer.xml" });
context.start();
CacheService cacheService = (CacheService)context.getBean("cacheService");
// 测试缓存生效，多次调用返回同样的结果。(服务器端自增长返回值)
String fix = null;
for (int i = 0; i < 5; i ++) {
String result = cacheService.findCache("0"); //request: 0, response: 1001
if (fix == null || fix.equals(result)) {
System.out.println("OK: " + result);
} else {
System.err.println("ERROR: " + result);
}
fix = result;
Thread.sleep(6000);
}
// LRU的缺省cache.size为1000，执行1001次，应有溢出，执行了1001次后1001*2=2002，所以result为2002
for (int n = 0; n < 1001; n ++) {
String pre = null;
for (int i = 0; i < 10; i ++) {
String result = cacheService.findCache(String.valueOf(n));
if (pre != null && ! pre.equals(result)) {
System.err.println("ERROR: " + result);
}
pre = result;
}
}
// 测试LRU有移除最开始的一个缓存项
String result = cacheService.findCache("0"); //request: 0, response: 2002
if (fix != null && ! fix.equals(result)) {
System.out.println("OK: " + result);
} else {
System.err.println("ERROR: " + result);
}
}
}