Springboot @Value Get the value null, workaround

In spring, you often use the @Value ("${property}") to take a value from the application.properties, you need to be aware of two points

1. Classes that use @Value cannot instantiate objects using the New keyword and must be instantiated in a dependency injection manner
2. You cannot use an explicit construction method

Otherwise, the value will not be taken. The workaround is as follows:

• Deleting an explicit construction method that requires content initialized with the constructor method can be used @postconstruct

@PostConstruct//Plus this annotation indicates that the method is called after the bean is initialized Private void init () {
Add your Content
}

• Using construction methods to inject

 Public Long reportperiod) {        this. reportperiod = reportperiod;          + "1111111111111111111111111111111111111111");            }

Springboot @Value Get the value null, workaround