Cannot get value from application.yml in static method-CodePudding

I cannot get value from application.yml in static method. However I could get the same value in my Controller. So, I think trying to reach that value from a static method. So, how can I fix it? I also tried to use constructor and set codeSize value, but still 0. Any idea?

@Component
@RequiredArgsConstructor
public class QRCodeGenerator {

    @Value("${qr-code.codeSize}")
    private static int codeSize;

    public static byte[] getQRCode(String data) throws IOException {

        // here codeSize value is 0 instead of 300 that I set in application.yml
        BitMatrix byteMatrix = qrCodeWriter.encode(codeSize, ...);

        // code omitted
    }
}

CodePudding user response：

I would not recommend it and would probably redesign your app structure, but if you're absolutely sure that you want a static method in your @Component and where you need to access the property value, here's a workaround you could use:

@Component
@RequiredArgsConstructor
public class QRCodeGenerator {
         
    private static int codeSize;

    @Value("${qr-code.codeSize}")
    public void setCodeSize(int codeSize){
       QRCodeGenerator.codeSize = codeSize;
    }

    public static byte[] getQRCode(String data) throws IOException {

        // here codeSize value is 0 instead of 300 that I set in application.yml
        BitMatrix byteMatrix = qrCodeWriter.encode(codeSize, ...);

        // code omitted
    }
}

CodePudding user response：

You are using Spring. The default scope is Singleton. So you anyway have only one instance of the bean.

Therefor you shouldn't use static at all in Spring beans.

@Component
@RequiredArgsConstructor
public class QRCodeGenerator {

    @Value("${qr-code.codeSize}")
    private final int codeSize;

    public byte[] getQRCode(String data) throws IOException {

        // here codeSize value is 0 instead of 300 that I set in application.yml
        BitMatrix byteMatrix = qrCodeWriter.encode(codeSize, ...);

        // code omitted
    }
}