spring-boot-configuration-processor fails compilation due to @DefaultValue with a long value and generates invalid metadata for byte and short properties with out-of-range default values

[roded]

Using Spring Boot 2.6.4.

package test;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.ConstructorBinding;
import org.springframework.boot.context.properties.bind.DefaultValue;
import org.springframework.validation.annotation.Validated;

@Validated
@ConstructorBinding
@ConfigurationProperties(prefix = "myprefix")
public class Test {

    private final long myLongValue;

    public Test(@DefaultValue("3221225472") long myLongValue) {
        this.myLongValue = myLongValue;
    }

    public long getMyLongValue() {
        return myLongValue;
    }
}

Error:

error: Invalid number representation '3221225472'
    public Test(@DefaultValue("3221225472") long myLongValue) {

[wilkinsona]

Thanks for the report. This looks like a bug to me as we're using Integer.parseInt(String) to convert a long's default value. We seem to use Integer.parseInt for all integral primitives. It might be worth some experimentation to see how that behaves if, for example, a short is configured with a default value that's larger than a short can contain.

[wilkinsona]

If you provide a default value that is out of range, the metadata will be generated successfully, but the default value will be invalid.

Subsequently, when the @DefaultValue is applied at runtime it fails:

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'myprefix' to com.example.demo.Test:

    Reason: failed to convert java.lang.String to @org.springframework.boot.context.properties.bind.DefaultValue short (caused by java.lang.NumberFormatException: Value out of range. Value:"12345678" Radix:10)

Action:

Update your application's configuration

I think we should catch this at compile time (as long as the annotation processor's in use) as this will ensure that the metadata isn't invalid.