對於@Primary注解的使用

當一個接口存在多個實現的時候會報org.springframework.beans.factory.NoUniqueBeanDefinitionException類似的異常信息,項目中碰到引用別人事先寫好的框架,但是對於其中個別實現並不是很需要,因此可以通過使用@Primary注解進行處理

比如處理登錄失敗時

@Component
public class OtherAuthenticationFailureHandler extends SimpleUrlAuthenticationFailureHandler {
    public HcAuthenticationFailureHandler() {
    }

    public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) {
        if (exception instanceof SessionAuthenticationException) {
            ResponseUtil.out(response, HttpStatus.UNAUTHORIZED, AjaxMessage.error("該賬戶登錄數量已達上限，請先下線別處的登錄！"));
        } else {
            ResponseUtil.out(response, HttpStatus.UNAUTHORIZED, AjaxMessage.error(exception.getMessage()));
        }

    }
}


我需要對返回的異常再進一步處理，@Primary指優先使用本處理器

@Primary
@Component
public class AuthenticationFailureHandler extends HcAuthenticationFailureHandler {

    @Override
    public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) {
        if (exception instanceof SessionAuthenticationException) {
            ResponseUtil.out(response, HttpStatus.UNAUTHORIZED, AjaxMessage.error("該賬戶登錄數量已達上限，請先下線別處的登錄！"));
        } else {
            if (exception instanceof ValidateLoginException && exception.getMessage().equals("賬戶不存在")) {
                ResponseUtil.out(response, HttpStatus.UNAUTHORIZED, AjaxMessage.error("用戶名或密碼錯誤"));
            } else {
                ResponseUtil.out(response, HttpStatus.UNAUTHORIZED, AjaxMessage.error(exception.getMessage()));
            }
        }

    }
}