java 评估 Spring Expression Lang (SpEL) 中的属性
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Evaluating properties inside Spring Expression Lang (SpEL)
提问by Sebastian
Our service has a process that is scheduled according to a properties file, reading the property refreshIntervalMillis. Its value is injected directly in a Quartz trigger with this configuration:
我们的服务有一个根据属性文件调度的进程，读取属性refreshIntervalMillis。它的值通过以下配置直接注入 Quartz 触发器中：
<bean name="trigger"
class="org.springframework.scheduling.quartz.SimpleTriggerFactoryBean "
p:repeatInterval="${refreshIntervalMillis}">
...
</bean>
However, the admins that install this service think in terms of hours/days, so in order to make thing easier for them, we changed this to:
但是，安装此服务的管理员以小时/天为单位考虑，因此为了让他们更轻松，我们将其更改为：
- Renamed refreshIntervalMillisto refreshIntervalMinutes
- Changed to code above to the following:
- 更名refreshIntervalMillis到refreshIntervalMinutes
- 将上面的代码改为如下：
p:repeatInterval="#{ 1000 * 60 * T(java.lang.Integer).valueOf(@configurationProperties['garbageLevelWatcher.refreshIntervalMinutes'])}"
Note: the properties object is exposed as a bean named "configurationProperties"
注意：属性对象公开为名为“configurationProperties”的 bean
Is there a simpler syntax to accomplish the same?
是否有更简单的语法来完成相同的操作？
Thanks,
谢谢，
回答by Gary Russell
"#{T(java.util.concurrent.TimeUnit).MINUTES.toMillis( @configurationProperties['garbageLevelWatcher.refreshIntervalMinutes'])}"
"#{T(java.util.concurrent.TimeUnit).MINUTES.toMillis( @configurationProperties['garbageLevelWatcher.refreshIntervalMinutes'])}"
EDIT:
编辑：
Or...
或者...
<context:property-placeholder properties-ref="configurationProperties"
<util:constant id = "MINUTES" static-field="java.util.concurrent.TimeUnit.MINUTES" />
and
和
"#{@MINUTES.toMillis(${garbageLevelWatcher.refreshIntervalMinutes})}"
回答by emd
If the properties are looked up by a PropertyPlaceholderConfigurer, @PropertySource or <context:property-placeholder /> and the context is aware of it
如果通过 PropertyPlaceholderConfigurer、@PropertySource 或 <context:property-placeholder /> 查找属性并且上下文知道它
You can write it like this:
你可以这样写：
p:repeatInterval="#{ 1000 * 60 * T(java.lang.Integer).valueOf('${garbageLevelWatcher.refreshIntervalMinutes}') }"
