《JavaEE进阶》----5.＜SpringMVC②剩余基本操作（Cookie&Session&Header&响应）＞

@RestController
@RequestMapping("/request")
public class RequestController {
    /**
     * 传统方法获取Cookie
     * 每个方法都内置了HttpServletRequest request/HttpServletResponse response对象
     * @param request
     * @param response
     * @return
     */
    @RequestMapping("/getCookie")
    public String getCookie(HttpServletRequest request, HttpServletResponse response){
        Cookie[] cookies = request.getCookies();//通过这种方式可以获取Cookie

        //我们使用lambda表达式的方式来打印Cookie。这种写法可以先了解一下。
//        Arrays.stream(cookies).forEach(x->{
//            System.out.println(x.getName() + ":" + x.getValue());
//        });
        //等价于使用foreach循环来打印Cookie
        for (Cookie c: cookies){
            System.out.println(c.getName()+":"+c.getValue());
        }
        return "获取Cookie成功！！！";
    }
}

    @RequestMapping("/getCookie")
    public String getCookie(HttpServletRequest request, HttpServletResponse response){
        Cookie[] cookies = request.getCookies();//通过这种方式可以获取Cookie
//使用foreach循环来打印Cookie
        if(cookies != null){
            for (Cookie c: cookies){
                System.out.println(c.getName()+":"+c.getValue());
            }
            return "获取Cookie成功！！！";
        }
        return "Cookie为空！";
    }

    @RequestMapping("getCookie2")
    public String getCookie2(@CookieValue("yang")String yang){
        return "yang:"+yang;
    }

    @RequestMapping("setSession")
    public String setSession(HttpServletRequest request){
        HttpSession session = request.getSession();
        session.setAttribute("student","zzx");
        return "设置Session成功！";
    }

    @RequestMapping("getSession")
    public String getSession(HttpServletRequest request){
        HttpSession session = request.getSession();
//默认值为ture，如果Session为null，就创建一个空的Session
        String student = (String) session.getAttribute("student");
        return "登录用户："+student;
    }

    @RequestMapping("getSession2")
    public String getSession(HttpSession session){
        String student = (String) session.getAttribute("student");
        return "登录用户："+student;
    }

    @RequestMapping("getSession3")
    public String getSession(@SessionAttribute("student")String student){
        return "登录用户："+student;
    }

    @RequestMapping("getSession3")
    public String getSession(@SessionAttribute(value = "student",required = false)String student){
        return "登录用户："+student;
    }

    @RequestMapping("/getHeader")
    public String getHeader(HttpServletRequest request){
        String userAgent = request.getHeader("User-Agent");
        return "userAgent:"+userAgent;
    }

    @RequestMapping("/getHeader2")
    public String getHeader2(@RequestHeader("User-Agent")String userAgent){
        return "userAgent:"+userAgent;
    }

@Controller
@RequestMapping("/return")
public class ReturnController {
    @RequestMapping("/r1")
    public String r1(){
        return "/index.html";
    }
}

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Controller
@ResponseBody
public @interface RestController {
    @AliasFor(
        annotation = Controller.class
    )
    String value() default "";
}

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface Controller {
    @AliasFor(
        annotation = Component.class
    )
    String value() default "";
}

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ResponseBody {
}

    @ResponseBody
    @RequestMapping("/r2")
    public String r2(){
        return "hello ，SpringMVC，我是返回的数据";
    }

    @ResponseBody
    @RequestMapping("/r3")
    public String r3(){
        return "<h1>hello ，SpringMVC，我是HTML片段</h1>";
    }

    @ResponseBody
    @RequestMapping("/r4")
    public UserInfo r4(){
        UserInfo userInfo = new UserInfo();
        userInfo.setName("zzx");
        userInfo.setId(9);
        userInfo.setAge(18);
        return userInfo;
    }

    @ResponseBody
    @RequestMapping("/r5")
    public Map<String,String> r5(){
        HashMap map = new HashMap<>();
        map.put("k1","v1");
        map.put("k2","v3");
        map.put("k3","v3");
        return map;
    }

    @RequestMapping("/r6")
    public String r6(){
        return "/a.js";
    }

    @RequestMapping("/r7")
    public String r7(){
        return "/b.css";
    }

    @ResponseBody
    @RequestMapping("/r8")
    public String r8(HttpServletResponse response){
        response.setStatus(401);
        return "设置状态成功！";
    }

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
public @interface RequestMapping {
    String name() default "";

    @AliasFor("path")
    String[] value() default {};

    @AliasFor("value")
    String[] path() default {};

    RequestMethod[] method() default {};

    String[] params() default {};

    String[] headers() default {};

    String[] consumes() default {};

    String[] produces() default {};
}

    @ResponseBody
    @RequestMapping(value = "/r9",produces = "application/json")
    public String r9(){
        return "自定义Header中的Content-Type成功！";
    }

    @ResponseBody
    @RequestMapping(value = "/r10")
    public String r10(HttpServletResponse response){
        response.setHeader("myHeader","myHeaderValue");
        return "自定义Header成功！";
    }