@Value annotation type casting to Integer from String

Question

I'm trying to cast the output of a value to an integer:

@Value("${api.orders.pingFrequency}")
private Integer pingFrequency;

The above throws the error

org.springframework.beans.TypeMismatchException: 
    Failed to convert value of type 'java.lang.String' to required type 'java.lang.Integer'; 
nested exception is java.lang.NumberFormatException: 
    For input string: "(java.lang.Integer)${api.orders.pingFrequency}"

I've also tried @Value("(java.lang.Integer)${api.orders.pingFrequency}")

Google doesn't appear to say much on the subject. I'd like to always be dealing with an integer instead of having to parse this value everywhere it's used.

Workaround

I realize a workaround may be to use a setter method to run the conversion for me, but if Spring can do it I'd rather learn something about Spring.

Answer 1

Assuming you have a properties file on your classpath that contains

api.orders.pingFrequency=4

I tried inside a @Controller

@Controller
public class MyController {     
    @Value("${api.orders.pingFrequency}")
    private Integer pingFrequency;
    ...
}

With my servlet context containing :

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

It worked perfectly.

So either your property is not an integer type, you don't have the property placeholder configured correctly, or you are using the wrong property key.

I tried running with an invalid property value, 4123;. The exception I got is

java.lang.NumberFormatException: For input string: "4123;"

which makes me think the value of your property is

api.orders.pingFrequency=(java.lang.Integer)${api.orders.pingFrequency}