在學習 Spring Mvc 過程中，有必要來先了解幾個關鍵參數：
@Controller：
在類上注解，則此類將編程一個控制器，在項目啟動 Spring 將自動掃描此類，並進行對應URL路由映射。
@Controller
public class UserAction
{
}
@RequestMapping
指定URL映射路徑，如果在控制器上配置 RequestMapping ，具體請求方法也配置路徑則映射的路徑為兩者路徑的疊加 常用映射如:RequestMapping("url.html")
配置映射路徑：
@Controller
public class UserAction
{
@RequestMapping(value = "/get_alluser.html")
public ModelAndView GetAllUser(String Id)
{
}
}
以上配置映射
http://***:8080:web1/get_alluser.html：
如在 @Controller添加 @RequestMapping(value = "/user"),則映射路徑變成
http://***:8080:web1/user/get_alluser.html
@ResponseBody
將注解方法對應的字符串直接返回
@RequestParam
自動映射URL對應的參數到Action上面的數值，RequestParam 默認為必填參數。
@PathVariable
獲取@RequestMapping 配置指定格式的URL映射參數
/*
* 直接輸出 HTML，或JSON 字符串
* 請求路徑:
* /web1/urlinfo/getcontent.html?key=rhythmk
* /web1/urlinfo/getcontent.json?key=rhythmk
* */
@ResponseBody
@RequestMapping(value = "/getcontent.**")
public String GetContent(
@RequestParam("key") String key,
@RequestParam(value = "key2", required = false, defaultValue = "defaultValue") String key2) {
System.out.println("getcontent 被調用");
String result = "直接返回內容 - key:" + key + ",key2:" + key2;
System.out.println(result);
return result;
}
/*
* RequestMapping 支持 Ant 風格的URL配置 ：
* 請求路徑：
* /urlinfo/geturlant/config.html?key=adddd
*/
@ResponseBody
@RequestMapping(value = "/geturlant/**.html")
public String getUrlAnt(HttpServletRequest request) {
String result = "?后面的參數為：" + request.getQueryString();
return result;
}
/*
* 配置指定格式的URL，映射到對應的參數
* 請求路徑：/web1/urlinfo/geturlparam/12_123.html
*
* */
@RequestMapping(value = "/geturlparam/{id}_{menuId}.html")
public ModelAndView getUrlParam(@PathVariable("id") String id,
@PathVariable("menuId") String menuId) {
ModelAndView mode = new ModelAndView(ShowMsg);
mode.addObject("msg", "獲取到的Id:" + id + ",menuId:" + menuId);
return mode;
}
/*
* 只接收Post 請求
*/
@ResponseBody
@RequestMapping(value = "/posturl.html", method = RequestMethod.POST)
public String UrlMethod(@RequestParam String id) {
return "只能是Post請求,獲取到的Id:" + id;
}
/*
* 寫入 cookie
* */
@RequestMapping("/writecookies.html")
public ModelAndView writeCookies(@RequestParam String value,
HttpServletResponse response) {
response.addCookie(new Cookie("key", value));
ModelAndView mode = new ModelAndView(ShowMsg);
mode.addObject("msg", "cookies 寫入成功");
return mode ;
}
/*
* 通過 @CookieValue 獲取對應的key的值
* */
@RequestMapping("/getcookies.html")
public ModelAndView getCookie(@CookieValue("key") String cookvalue) {
ModelAndView mode = new ModelAndView(ShowMsg);
mode.addObject("msg", "cookies=" + cookvalue);
return mode;
}
/*
* 將 Servlet Api 作為參數傳入
* 可以在action中直接使用 HttpServletResponse，HttpServletRequest
* */
@RequestMapping("/servlet.html")
public String Servlet1(HttpServletResponse response,
HttpServletRequest request) {
Boolean result = (request != null && response != null);
ModelAndView mode = new ModelAndView();
mode.addObject("msg", "result=" + result.toString());
return ShowMsg;
}
/*
* 根據URL傳入的參數實例化對象
*
* 如： http://127.0.0.1:8080/web1/urlinfo/getobject.html?UserId=1&UserName=ad
* */
@RequestMapping("getobject.html")
public ModelAndView getObject(UserInfo user) {
String result = "用戶ID：" + user.getUserId().toString() + ",用戶名:"
+ user.getUserName().toString();
ModelAndView mode = new ModelAndView(ShowMsg);
mode.addObject("msg", "result=" + result.toString());
return mode;
}
實現頁面跳轉：
/*
* 實現頁面跳轉
* /web1/urlinfo/redirectpage.html
* */
@RequestMapping("/redirectpage.html")
public String RedirectPage()
{
return "redirect:getcookies.html?r=10";
}
直接回傳JSON
請求的URL地址一定是以.json結尾，否則異常
Failed to load resource: the server responded with a status of 406 (Not Acceptable) ： The resource identified by this request is only capable of generating responses with characteristics not acceptable according to the request "accept" headers ()
回傳實體：
@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class UserInfo {
private Integer UserId;
public Integer getUserId() {
return UserId;
}
public void setUserId(Integer userId) {
UserId = userId;
}
public String getUserName() {
return UserName;
}
public void setUserName(String userName) {
UserName = userName;
}
private String UserName;
}
回傳 action
@ResponseBody
@RequestMapping("/getuser.json")
public UserInfo GetUser()
{
System.out.println("getuser");
UserInfo model=new UserInfo();
model.setUserId(100);
model.setUserName("王坤");
return model;
}
請求：
/web1/urlinfo/getuser.json
輸出：
{"userId":100,"userName":"王坤"}