使用Redis的骡子缓存策略

Question

我正在寻找一种方法来在两台服务器之间共享缓存，我正在研究使用Redis作为对象存储缓存策略，但是在读取存储值时遇到问题。

当缓存命中是未命中值时，它会成功存储值，但在检索该值时会引发错误。

所需的对象/属性“muleContext”为空

在猜测它看起来像对象店缓存策略可能需要一个实现MuleContextAware接口的对象存储。

有谁知道这是否正确或如何解决此问题？

这里是例如流

<mule xmlns:redis="http://www.mulesoft.org/schema/mule/redis" xmlns:ee="http://www.mulesoft.org/schema/mule/ee/core" 
    xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:spring="http://www.springframework.org/schema/beans" version="EE-3.4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mulesoft.org/schema/mule/ee/core http://www.mulesoft.org/schema/mule/ee/core/current/mule-ee.xsd 
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd 
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd 
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd 
http://www.mulesoft.org/schema/mule/redis http://www.mulesoft.org/schema/mule/redis/3.4/mule-redis.xsd"> 


    <redis:config name="Redis" doc:name="Redis" defaultPartitionName="test" /> 
    <ee:object-store-caching-strategy name="Redis_Caching_Strategy" doc:name="Caching Strategy"> 
     <spring-object-store ref="Redis" /> 
    </ee:object-store-caching-strategy> 

    <flow name="htmlCacheRedisFlow" doc:name="htmlCacheRedisFlow"> 
     <http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8084" path="cacheRedis" doc:name="HTTP"/> 
     <expression-transformer expression="#[payload.substring(payload.lastIndexOf('/') + 1)]" doc:name="Expression"/> 
     <ee:cache doc:name="Cache" cachingStrategy-ref="Redis_Caching_Strategy" > 
      <logger message="getting item from db for key #[payload]" level="INFO" doc:name="Logger"/> 
      <expression-transformer expression="#[payload + 'asd']" doc:name="Expression"/> 
     </ee:cache> 
    </flow> 
</mule> 

Answer 1

由于已经由大卫指出，在这个问题的意见中，EE缓存范围在社区版本可用。但是有一些方法可以在社区版中实现缓存。

博客文章Enterprise caching with Mule ESB Community Edition显示了如何通过添加自定义拦截器来完成此操作。博客文章使用ehcache，但您可以修改此示例以使用Redis。

博客文章简言之就是：

<custom-interceptor doc:name="PayloadCache" 
    class="se.redpill.mulecomponents.cache.PayloadCache"> 
    <spring:property name="cache" ref="MyCache"/> 
</custom-interceptor> 

和PayloadCache.java

package se.redpill.mulecomponents.cache; 
import net.sf.ehcache.Ehcache; 
import net.sf.ehcache.Element; 
import org.mule.DefaultMuleEvent; 
import org.mule.DefaultMuleMessage; 
import org.mule.api.MuleEvent; 
import org.mule.api.MuleException; 
import org.mule.api.MuleMessage; 
import org.mule.api.interceptor.Interceptor; 
import org.mule.api.processor.MessageProcessor; 
/** 
* A mule interceptor acting as a ehCache component. 
* Based on the Cache interceptor blueprint from Mule In Action by David Dossot and John D'Emic, 
* 
*/ 
public class PayloadCache implements Interceptor 
{  
     private MessageProcessor next; 
     private Ehcache cache; 
     public void setListener(MessageProcessor listener) 
     { 
     next = listener; 
     } 
     public void setCache(final Ehcache cache) 
     { 
     this.cache = cache; 
     } 
     public MuleEvent process(MuleEvent event) throws MuleException 
     { 
     final MuleMessage currentMessage = event.getMessage(); 
     final Object key = currentMessage.getPayload(); 
     final Element cachedElement = cache.get(key); 
     if (cachedElement != null) 
     { 
      return new DefaultMuleEvent(new DefaultMuleMessage(cachedElement.getObjectValue(), 
      currentMessage, event.getMuleContext()), event); 
     } 
     final MuleEvent result = next.process(event); 
     cache.put(new Element(key, result.getMessage().getPayload())); 
     return result; 
     } 
}