@RequestMapping使用或不使用斜杠值。需要官方文档或指向Spring源码吗？

没关系：如果路径不是以开头，

/

参见

String[] determineUrlsForHandler(StringbeanName)

DefaultAnnotationHandlerMapping

String[] methodLevelPatterns = determineUrlsForHandlerMethods(handlerType, true);for (String typeLevelPattern : typeLevelPatterns) {    if (!typeLevelPattern.startsWith("/")) { typeLevelPattern = "/" + typeLevelPattern;    }

参见

String[] determineUrlsForHandler(Class<?> handlerType, final booleanhasTypeLevelMapping))

DefaultAnnotationHandlerMapping

String[] mappedPatterns = mapping.value();if (mappedPatterns.length > 0) {for (String mappedPattern : mappedPatterns) {    if (!hasTypeLevelMapping && !mappedPattern.startsWith("/")) {        mappedPattern = "/" + mappedPattern;    }