我一直在阅读有关 Camel 属性的以下页面: http: //camel.apache.org/using-propertyplaceholder.html 并阅读了“Camel In Action”一书。
我发现“Camel In Action”的第 6 章对定义 Camel 属性非常有帮助,我可以从我的 config.properties 中加载以下三个属性:
config.timeout=10000
config.numSamples=1000
config.defaultViz=a
当我运行我的 Java 代码时,我可以在 applicationContext.xml 的骆驼路线中看到以下三个值,如下面的 thread#0 消息所示:
14669 [Camel (HelloWorldContext) thread #0 - timer://hello.world.request.timer] INFO route1 - printing values read from config.properties file
14669 [Camel (HelloWorldContext) thread #0 - timer://hello.world.request.timer] INFO route1 - config.timeout= 10000
14669 [Camel (HelloWorldContext) thread #0 - timer://hello.world.request.timer] INFO route1 - config.numSamples= 1000
14670 [Camel (HelloWorldContext) thread #0 - timer://hello.world.request.timer] INFO route1 - config.defaultViz= a
但是,当我尝试将变量 {{config.defaultViz}} 传递给我的 SensorGenerator Java 类中名为 defaultViz 的字符串并打印该字符串时,我在控制台上得到“{{config.defaultViz}}”而不是包含的值在 {{config.defaultViz}} 内。
换句话说,这就是我在屏幕上看到的:
Returning List
defaultViz= {{config.defaultViz}}
但我真的很想在屏幕上看到这个:
Returning List
defaultViz=a
那么我在 applicationContext.xml 中做错了什么?
更新:问题是我需要在 Spring 和 Camel 之间添加一座桥梁,如我上面引用的链接中所述。
这是我的更新 applicationContext.xml 与桥:
<?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:camel="http://camel.apache.org/schema/spring"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<bean
class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />
<context:component-scan base-package="com.data.world2" />
<context:annotation-config />
<camel:camelContext id="HelloWorldContext">
<!-- Add Jackson library to render Java Map into JSON -->
<camel:dataFormats>
<camel:json id="jack" library="Jackson"/>
</camel:dataFormats>
<camel:route>
<!-- sends a request to the hello world JMS queue every 10 seconds -->
<camel:from
uri="timer://hello.world.request.timer?fixedRate=true&period={{config.timeout}}" />
<camel:to uri="log:hello.world.request?level=INFO&showAll=true" />
<camel:bean ref="helloWorld" />
<!-- now print out the map in JSON format -->
<camel:marshal ref ="jack"/>
<camel:convertBodyTo type="java.lang.String" />
<camel:log message="${body}"/>
<!-- print out values read from config.properties file -->
<camel:log message="printing values read from config.properties file"/>
<camel:log message="config.timeout= {{config.timeout}}"/>
<camel:log message="config.numSamples= {{config.numSamples}}"/>
<camel:log message="config.defaultViz= {{config.defaultViz}}"/>
<!-- now log the message -->
<camel:to uri="log:hello.world.response?level=INFO&showAll=true" />
</camel:route>
</camel:camelContext>
<!-- creates a java.util.Properties instance with values loaded from the supplied location -->
<util:properties id="sensorProperties" location="classpath:/sensor.properties"/>
<!-- pass in sensor.properties and defaultViz from config.properties -->
<bean class="com.data.world2.SensorGenerator">
<property name="sourceProperties" ref="sensorProperties" />
<property name="defaultViz" value="${config.defaultViz}"/>
</bean>
<!-- declare a Spring bean to use the Camel Properties component in Spring XML -->
<bean id="properties"
class="org.apache.camel.component.properties.PropertiesComponent">
<property name="location" value="classpath:config.properties"/>
</bean>
<!-- bridge spring property placeholder with Camel -->
<!-- you must NOT use the <context:property-placeholder at the same time, only this bridge bean -->
<bean id="bridgePropertyPlaceholder" class="org.apache.camel.spring.spi.BridgePropertyPlaceholderConfigurer">
<property name="location" value="classpath:config.properties"/>
</bean>
</beans>
我发现这个问题相似但不完全相同:Injecting property into bean