注解@ModelAttribute

 

@Target({ElementType.PARAMETER, ElementType.METHOD})     //可以看到注解ModelAttribute 可以在方法的参数和方法上面使用
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ModelAttribute {
    @AliasFor("name")
    String value() default "";

    @AliasFor("value")
    String name() default "";

    boolean binding() default true;
}
//被 @ModelAttribute 注释的方法会在Controller每个方法执行之前都执行，因此对于一个Controller中包含多个URL的时候，要谨慎使用

public class Attribute {

    protected HttpServletResponse response;

    protected HttpServletRequest request;

    @ModelAttribute       //请求过来先访问此方法 在访问getAttribute
    public void setResponseAndReq(HttpServletRequest request, HttpServletResponse response, Model model,@RequestParam(value="userName",required=false) String userName) {
        this.response = response;
        this.request = request;
        model.addAttribute("name",userName);
    }

    @RequestMapping(value = "/attribute",method = RequestMethod.POST)
    public void getAttribute(ModelMap modelMap,String userName) {
        System.out.println(modelMap.get("name"));

    }
}

//可以声明一个BaseController 用来校验TOKEN  继承BaseController

public class BaseController {
    /**
     * request对象
     */
    protected HttpServletRequest request;

    /**
     * response对象
     */
    protected HttpServletResponse response;

    @ModelAttribute  //
    public void setReqAndRes(HttpServletRequest request, HttpServletResponse response) {
        this.request = request;
        this.response = response;
    }

    /**
     * 获取当前登录用户的ID
     * @return
     */
    public Long getUserId(){
        String appToken = request.getHeader("token");
        ChatToken chatToken=employeeService.getUserInfoByToken(appToken);
        if(chatToken!=null){
            return chatToken.getUserId();
        }
        return null;
    }

    /**
     * 获取当前用户的token
     * @return
     */
    public String getToken(){
        String appToken = request.getHeader("token");

        return appToken;
    }

    /**
     * 获取当前登录用户会话对象
     * @return
     */
    public boolean getChatToken(){
        String appToken = request.getHeader("token");
　　　　// dosomething    
　　　　return boolean;
　　}
}