Why in the below case @value("${someProperty}") is working while @value("#{someProperty}"), is not working [duplicate]

Question

I have the below spring configuration:

<context:property-placeholder location="classpath:commonSql.properties" />

Now in my class, when I use @value("#{someproperty}") it did not work. Then, I changed to @value("${someproperty}") and it worked.

According to answer of this questions @value("#{someproperty}") is SpEL syntax, which is far more capable and complex. It can also handle property placeholders, and a lot more besides but in my case why it's not working ? While the simple one is working how both $ and # are use to evaluate the value.

The main thing is @value("#{someproperty}") is not working while @value("${someproperty}") is working.

Answer 1

#{ } is an expression language feature, while ${ } is a simple property placeholder syntax.

Expression language means that there is a specific syntax, objects, variables and so on.

When you write "#{someproperty}", you actually referring to the object and expression language engine answers you:

Field or property 'someproperty' cannot be found on object of type 'org.springframework.beans.factory.config.BeanExpressionContext'

Here is what will work:

  @Value("#{'${someproperty}'}")