这块代码看的不是太懂，请大神帮忙

[坚持的奋斗者]

@RequestMapping("/pro/fwpj/fwpjlst.htm")
    public ModelAndView fwpjlst(HttpServletRequest request, @RequestParam(value = "page", required = false, defaultValue = "1") int currentPage,
            @RequestParam(value = "sfpj", required = false, defaultValue = "-1") int sfpj) throws Exception {
        ProUser proUser = getProUser();
        int allnum = fwpjService.getCountByZjhm(proUser.getZjhm(), FwpjConstant.SFPJ_ALL);
        int ypjnum = fwpjService.getCountByZjhm(proUser.getZjhm(), FwpjConstant.SFPJ_YPJ);
        int wpjnum = allnum - ypjnum;
        List<Map<String, Object>> vfwpjLst = fwpjService.getFwpjListByZjhm(proUser.getZjhm(), currentPage, sfpj);
        Timestamp date = this.ajService.getStartTime();
        request.setAttribute("startDate", date);
        request.setAttribute("fwpjLst", vfwpjLst);
        if (sfpj == 1) {
            request.setAttribute("qnum", ypjnum);
        } else if (sfpj == 2) {
            request.setAttribute("qnum", wpjnum);
        } else {
            request.setAttribute("qnum", allnum);
        }
        request.setAttribute("ypjnum", ypjnum);
        request.setAttribute("wpjnum", wpjnum);
        request.setAttribute("allnum", allnum);
        request.setAttribute("page", currentPage);
        request.setAttribute("rows", ZxxxUtils.ROWS);
        request.setAttribute("sfpj", sfpj);
        return new ModelAndView("/pro/blue/fwpj/fwpjlst");
    }

这块代码设置request属性后，没有重定向到另一个jsp页面，反而返回了一个ModelAndView，为什么要这样呢？小白一枚，请大神指教