Camel-blueprint

在camel路由时，使用blueprint属性占位器。

camel支持blueprint，blueprint提供属性占位器服务。

camel支持“覆盖配置”公约，所以我们得在xml文档中定义blueprint属性占位器。

样例：

<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.0.0" 
xsi:schemaLocation=" 
http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/ 
blueprint/v1.0.0/blueprint.xsd"> 
<!-- OSGI blueprint property placeholder --> 
<cm:property-placeholder id="myblueprint.placeholder" 
persistent-id="camel.blueprint"> 
<!-- list some properties for this test --> 
<cm:default-properties> 
<cm:property name="result" value="mock:result"/> 
</cm:default-properties> 
</cm:property-placeholder> 
<camelContext xmlns="http://camel.apache.org/schema/blueprint"> 
<!-- in the route we can use {{ }} placeholders which will lookup in blueprint 
as Camel will auto detect the OSGi blueprint property placeholder and use 
it --> 
<route> 
<from uri="direct:start"/> 
<to uri="mock:foo"/> 
<to uri="{{result}}"/> 
</route> 
</camelContext> 
</blueprint> 

说明：缺省情况下，camel会探测和使用OSGI blueprint的属性占位器服务。我们可以通过设置属性：useBlueprintPropertyResolver=false（在<camelContext>中设置）来制止这种默认行为。