java Spring 表达式语言 (SpEL)：将 String 解析为 int
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Spring expression language (SpEL): parse String to int
提问by Jan Van den bosch
I've got a (String, obviously) property expressed in minutes that I want to convert to an intbefore I do some arithmetic and inject it into my Spring bean. Right now I have this SpEL expression:
我有一个String以分钟表示的 ( ，显然) 属性，int在我做一些算术并将其注入我的 Spring bean 之前，我想将其转换为 an 。现在我有这个 SpEL 表达式：
#{T(java.lang.Integer).parseInt(myProperties['MIN_TIME']) * 60 * 1000}
where myPropertiesis a simple java.util.Propertiesbean.
哪里myProperties有一个简单的java.util.Propertiesbean。
Not that I'm particularly annoyed by this expression, but nevertheless: does the SpEL have a prettier, built-in way to parse strings into numeric values?
并不是说我对这个表达式特别恼火，但是：SpEL 是否有更漂亮的内置方法来将字符串解析为数值？
Thanks!
谢谢！
回答by artbristol
Doesn't look like it, e.g. look at how the developers create them here: https://jira.springsource.org/browse/SPR-8716
看起来不像，例如看看开发人员如何在这里创建它们：https: //jira.springsource.org/browse/SPR-8716
A slightly shorter version could be
一个稍短的版本可能是
#{new Integer(myProperties['MIN_TIME']) * 60 * 1000}
回答by user2663570
Another way to do this is to use the util namespace to define a properties bean, ... xmlns:util="http://www.springframework.org/schema/util" ... http://www.springframework.org/schema/utilhttp://www.springframework.org/schema/util/spring-util-3.1.xsd...
另一种方法是使用 util 命名空间来定义属性 bean，... xmlns:util="http://www.springframework.org/schema/util" ... http://www.springframework。 org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd...
<util:properties id="apiProperties"
location="classpath:/api.properties" />
then use the alternate syntax for the properties bean
然后使用属性 bean 的替代语法
@Value("#{apiProperties['api.orders.pingFrequency']}")
private Integer pingFrequency;
The spring util properties bean generated by context will do the parse and conversion before assigning the value.
由上下文生成的 spring util 属性 bean 将在分配值之前进行解析和转换。
