@value Annotations in Spring

There are many ways to find @value in the project

The role of @value injection:

The external values are injected dynamically into the bean by @value.

1, can inject ordinary string

2. Inject operating System Properties

3. Inject expression results

4. Inject Other bean properties

5. Inject File Resources

6. Inject URL Resources

@value ("Nomalchacter")

Private String char;//Inject ordinary characters

@value ("#{sytemproperties[' Os.name '}")

Private String systempropertiesname;//injected into the operating system

@value ("#{t (Java.lang.Math). Random () *100.0}")

Private double randomnumber;//injection expression result

@Value ("#{bean.name}")

Private String Fromanotherbean; Inject other bean properties: Inject the properties of the Beaninject object name

@Value ("Classpath:com/1.txt")

Private Resource resourcefile; Inject File Resources

@Value ("http://www.gogle.com")

Private Resource Testurl; Inject URL Resource

The value of the property file is injected into the Bean property value by @value ("${app.name}") syntax.

@Value ("${person.name}")

private String name;

@Value ("${person.name.firstname}")

Private String firstname;//injected with name FirstName

There are #{} and ￥{} in the above usage, what is the difference between them?

#{..} Primarily used to execute Spel expressions and assign content to properties

${..} Used primarily to load values from an external properties file

#{..} and ${...} Can be mixed, but must #{} outside, ${} in it