java控制器的返回值

java 控制器的返回值有多种，可以是String ,ModelAndView,ResponseResults等

1 String类型的有一下几种情况

@RequestMapping("/show") public String findAll(Model model, HttpServletResponse response, HttpServletRequest request) throws IOException{ List<User> userList = userService.findAll(); model.addAttribute("userList", userList); response.getWriter().print("{success:true}"); return "/sys/user"; } //带参数跳转页面 @RequestMapping("/view") public String listView(Model model,String userkey,HttpServletResponse response)throws Exception { User user = userService.findByUserkey(userkey); model.put("user",user); return "/sys/user/view"; } //返回json字符串 @RequestMapping(value = "/sys/sysuser/list" ,produces = "text/html;charset=UTF-8") @ResponseBody public String list(User user, String regionCode1, int page , int size, HttpServletRequest request) { Pageable pageable = PageRequest.of(page, size); try { Criteria<User> criteria =new Criteria<>(); Page<User> pageList = userService.findAll(criteria, pageable); return JSON.toJSONString(pageList); } catch (Exception e) { e.printStackTrace(); return JSON.toJSONString(new PageImpl<SysUser>(new ArrayList<>(), pageable, 0)); } } //光跳转页面 @RequestMapping("/view") public String listView(){ return "/sys/user/view" }

2,ModelAndView

//只跳转页面 @RequestMapping("/room_struct3") public ModelAndView room_struct3() { return new ModelAndView("/struct/room_struct3"); } //跳转页面带参数 @RequestMapping("/room_struct3") public ModelAndView room_struct3() { Map<String,Object> model = new HashMap<>(); User user = userService.findByUserkey(userkey); model.put("user",user); return new ModelAndView("/struct/room_struct3",model); }

3,ResponseResults

@RequestMapping("/save") public ResponseResults save(User user){ User user1 = userService.save(user); return ResponseResults.ok() //return ResponseResults.ok(user1); //return ResponseResults.error(); //return ResponseResults.error("错误信息"); }

ResponseResults工具类

package com.laopei.wahaha.util; import java.util.HashMap; public class ResponseResults extends HashMap<String, Object> { private static final long serialVersionUID = -8713837118340960775L; // 成功 private static final Integer SUCCESS = 0; // 警告 private static final Integer WARN = 1; // 异常 失败 private static final Integer FAIL = 500; public ResponseResults() { put("code", SUCCESS); put("msg", "操作成功"); } public static ResponseResults error(Object msg) { ResponseResults responseResults = new ResponseResults(); responseResults.put("code", FAIL); responseResults.put("msg", msg); return responseResults; } public static ResponseResults warn(Object msg) { ResponseResults responseResults = new ResponseResults(); responseResults.put("code", WARN); responseResults.put("msg", msg); return responseResults; } public static ResponseResults ok(Object msg) { ResponseResults responseResults = new ResponseResults(); responseResults.put("code", SUCCESS); responseResults.put("msg", msg); return responseResults; } public static ResponseResults ok() { return new ResponseResults(); } public static ResponseResults error() { return ResponseResults.error(""); } @Override public ResponseResults put(String key, Object value) { super.put(key, value); return this; } }