在学习 Spring Mvc 过程中，有必要来先了解几个关键参数：
@Controller：
在类上注解，则此类将编程一个控制器，在项目启动 Spring 将自动扫描此类，并进行对应URL路由映射。
@Controller
public class UserAction
{
}
@RequestMapping
指定URL映射路径，如果在控制器上配置 RequestMapping ，具体请求方法也配置路径则映射的路径为两者路径的叠加 常用映射如:RequestMapping("url.html")
配置映射路径：
@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"),则映射路径变成
http://***:8080:web1/user/get_alluser.html
@ResponseBody
将注解方法对应的字符串直接返回
@RequestParam
自动映射URL对应的参数到Action上面的数值，RequestParam 默认为必填参数。
@PathVariable
获取@RequestMapping 配置指定格式的URL映射参数
/*
* 直接输出 HTML，或JSON 字符串
* 请求路径:
* /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 被调用");
String result = "直接返回内容 - key:" + key + ",key2:" + key2;
System.out.println(result);
return result;
}
/*
* RequestMapping 支持 Ant 风格的URL配置 ：
* 请求路径：
* /urlinfo/geturlant/config.html?key=adddd
*/
@ResponseBody
@RequestMapping(value = "/geturlant/**.html")
public String getUrlAnt(HttpServletRequest request) {
String result = "?后面的参数为：" + request.getQueryString();
return result;
}
/*
* 配置指定格式的URL，映射到对应的参数
* 请求路径：/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", "获取到的Id:" + id + ",menuId:" + menuId);
return mode;
}
/*
* 只接收Post 请求
*/
@ResponseBody
@RequestMapping(value = "/posturl.html", method = RequestMethod.POST)
public String UrlMethod(@RequestParam String id) {
return "只能是Post请求,获取到的Id:" + id;
}
/*
* 写入 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 写入成功");
return mode ;
}
/*
* 通过 @CookieValue 获取对应的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;
}
/*
* 将 Servlet Api 作为参数传入
* 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;
}
/*
* 根据URL传入的参数实例化对象
*
* 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 = "用户ID：" + user.getUserId().toString() + ",用户名:"
+ user.getUserName().toString();
ModelAndView mode = new ModelAndView(ShowMsg);
mode.addObject("msg", "result=" + result.toString());
return mode;
}
实现页面跳转：
/*
* 实现页面跳转
* /web1/urlinfo/redirectpage.html
* */
@RequestMapping("/redirectpage.html")
public String RedirectPage()
{
return "redirect:getcookies.html?r=10";
}
直接回传JSON
请求的URL地址一定是以.json结尾，否则异常
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 ()
回传实体：
@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;
}
回传 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;
}
请求：
/web1/urlinfo/getuser.json
输出：
{"userId":100,"userName":"王坤"}