spring-hateoas-ext/src/main/java/de/escalon/hypermedia/spring/SpringActionInputParameter.java
public String getDefaultValue() {
        String ret;
        if (isRequestParam()) {
            ret = isDefined(requestParam.defaultValue()) ?
                    requestParam.defaultValue() : null;
        } else if (isRequestHeader()) {
            ret = !(ValueConstants.DEFAULT_NONE.equals(requestHeader.defaultValue())) ?
                    requestHeader.defaultValue() : null;
        } else {
            ret = null;
        }
        return ret;
    }
public String getDefaultValue() {
        String ret;
        if (isRequestParam()) {
            ret = isDefined(requestParam.defaultValue()) ?
                    requestParam.defaultValue() : null;
        } else if (isRequestHeader()) {
            ret = !(ValueConstants.DEFAULT_NONE.equals(requestHeader.defaultValue())) ?
                    requestHeader.defaultValue() : null;
        } else {
            ret = null;
        }
        return ret;
    }
Determines default value of request param or request header, if available.

@return value or null