AJAX跨域实现：Java后端处理与JSON中文编码

//baseAction
public void writecallback(HttpServletRequest request,
HttpServletResponse response, Object obj) {
String callbackFunName = request.getParameter("callbackparam");// 得到js函数名称
String uuid = UUID.randomUUID().toString().replace("-", "");
try {
response.setContentType("text/plain");
String json = JSON.toJSONString(obj);
response.getWriter().write(callbackFunName + "([" + json + "])"); // 返回jsonp数据
log.error(String.format("响应信息: <%s>%s  %s",
request.getRequestURI(), uuid, JSON.toJSONString(obj)));
} catch (IOException e) {
log.error("writecallback excption -> ", e);
log.error(String.format("响应信息: <%s>%s  %s",
request.getRequestURI(), uuid, JSON.toJSONString(obj)));
}
}

//Action
@RequestMapping("/relatSaveOrUpdate")
@ResponseBody
public void relatSaveOrUpdate(@RequestBody String params,  String map, HttpServletRequest request, HttpServletResponse response) {
String p=request.getParameter("str");
response.setHeader("Access-Control-Allow-Origin", "*");
writecallback(request, response, sensitiveService.relatSaveOrUpdate(p));
}

//serviceimpl
public Map<String, Object> relatSaveOrUpdate(String map) {
Map<String, Object> m=new HashMap<String, Object>();