How to limit the usage of types converter to a specific controller in Spring MVC?

When dealing with request parameters, path variables or form fields in Spring MVC I have to handle typeMismatch errors. They occur just before the validation even begins, which can be irritating at times. Let's say I have an Integer parameter annotated with standard validation constraint, sort of: @Min(value = 0, message = "Only non-negative integer values can be accepted"). Then, I could create a simple String to Integer converter to suppresses NumberFormatException while setting all unparsable String values to -1, so that they could be further invalidated by aforementioned @Min constraint:

@Component
final class StringToInteger implements Converter<String, Integer> {

    public Integer convert(String source) {
		try{
			return Integer.valueOf(source);
		} catch (NumberFormatException ex) {
			return -1;
		}
    }

}

When using with Spring Boot, the @Component annotation automatically gets this converter up and running within the entire application context, but what if I want to limit its usage only to a specific Controller or even a target request? What is the simplest way to do that?

You can use DataBinder. You declare it inside your controller.

	@InitBinder
	public void customizeBinding (DataBinder binder) {
    	DefaultConversionService conversionService = new DefaultConversionService();
	    conversionService.addConverter(new StringToInteger());
		binder.setConversionService(conversionService);
    }

EDIT: you can use a formatter instead.

@InitBinder
public void customizeBinding (DataBinder binder) {
	binder.addCustomFormatter(new StringToInteger());
}

class StringToInteger implements Formatter<Integer> {

	@Override
	public Integer parse(String s, Locale locale) throws ParseException {
		try {
			return Integer.valueOf(s);
		}
		catch (NumberFormatException ex) {
			return -1;
		}
	}

	@Override
	public String print(Integer i, Locale locale) {
		return Objects.toString(i);
    }
}