I had the same use case, You can change your method defination in the following way :
@RequestMapping(value = "/saveFruits", method = RequestMethod.POST,
consumes = "application/json")
@ResponseBody
public ResultObject saveFruits(@RequestBody Map<String,List<String>> fruits) {
..
}
The only problem is it accepts any key in place of "fruits" but You can easily get rid of a wrapper if it is not big functionality.