spring boot补习系列之几种scope详解

 @GetMapping("/some")
 @ResponseBody
 public String someHeader(@RequestHeader(value = "Host") String host,
  @RequestHeader(value = "User-Agent") String userAgent,
  @RequestHeader(value = "Cache-Control", required = false) String cacheControl,
  HttpServletResponse response) {

 logger.info("host:{}", host);
 logger.info("User-Agent:{}", userAgent);
 logger.info("Cache-Control:{}", cacheControl);

 // 设置响应头
 response.setHeader("Cache-Control", "no-cache,no-store,must-revalidate");
 response.setHeader("Pragma", "no-cache");
 response.setDateHeader("Expires", 0);
 return "OK";
 }

 @GetMapping("/all")
 public ResponseEntity<Map<String, List<String>>> allHeaders(@RequestHeader HttpHeaders headers) {

 Map<String, List<String>> valueMap = new HashMap<String, List<String>>();
 for (String header : headers.keySet()) {
  valueMap.put(header, headers.get(header));
  logger.info("header[{}]={}", header, headers.get(header));
 }

 // 通过ResponseEntity设置响应头
 ResponseEntity<Map<String, List<String>>> entity = ResponseEntity.status(HttpStatus.OK)
  .header("new header", UUID.randomUUID().toString()).body(valueMap);
 return entity;
 }

SpringBoot 提供了@CookieValue以支持参数方式注入，如下：

 @GetMapping("/some")
 @ResponseBody
 public String someCookie(@CookieValue(value = "counter", defaultValue = "0") int counter,
  HttpServletResponse response) {

 logger.info("counter:{}", counter);
 counter += 1;

 String newValue = counter + "";

 // 设置Cookie
 response.addCookie(new Cookie("counter", newValue));
 return newValue;
 }

 @GetMapping("/all")
 public ResponseEntity<Map<String, String>>allCookies(HttpServletRequest request, HttpServletResponse response) {

 Map<String, String> valueMap = new HashMap<String, String>();
 for (Cookie cookie : request.getCookies()) {

  valueMap.put(cookie.getName(), cookie.getValue());
  logger.info("cookie[{}]={}", cookie.getName(), cookie.getValue());
 }

 // 设置Cookie
 response.addCookie(new Cookie("key", UUID.randomUUID().toString()));
 return new ResponseEntity<Map<String, String>>(valueMap, HttpStatus.OK);
 }

 @GetMapping("/clear")
 public ResponseEntity<Map<String, String>> clearCookies(HttpServletRequest request, HttpServletResponse response) {

 Map<String, String> valueMap = new HashMap<String, String>();
 for (Cookie cookie : request.getCookies()) {

  valueMap.put(cookie.getName(), cookie.getValue());
  logger.info("cookie[{}]={}", cookie.getName(), cookie.getValue());

  // 清除
  cookie.setMaxAge(0);
  response.addCookie(cookie);
 }

 return new ResponseEntity<Map<String, String>>(valueMap, HttpStatus.OK);
 }

@SessionAttributes("seed")
public class SessionController {

 private static final Logger logger = LoggerFactory.getLogger(SessionController.class);
 @GetMapping("/some")
 @ResponseBody
 public String someSession(@SessionAttribute(value = "seed", required = false) Integer seed, Model model) {

  logger.info("seed:{}", seed);
  if (seed == null) {
   seed = (int) (Math.random() * 10000);
  } else {
   seed += 1;
  }
  model.addAttribute("seed", seed);

  return seed + "";
 }

 @GetMapping("/all")
 public ResponseEntity<Map<String, Object>> allSessions(HttpSession session) {

  Map<String, Object> valueMap = new HashMap<String, Object>();
  Enumeration<String> iSession = session.getAttributeNames();

  while (iSession.hasMoreElements()) {
   String sessionName = iSession.nextElement();
   Object sessionValue = session.getAttribute(sessionName);

   valueMap.put(sessionName, sessionValue);
   logger.info("sessoin[{}]={}", sessionName, sessionValue);
  }

  // 写入session
  session.setAttribute("timestmap", new Date());
  return new ResponseEntity<Map<String, Object>>(valueMap, HttpStatus.OK);
 }

 @GetMapping("/clear")
 public ResponseEntity<Map<String, Object>> clearSessions(HttpSession session) {

  Map<String, Object> valueMap = new HashMap<String, Object>();
  Enumeration<String> iSession = session.getAttributeNames();

  while (iSession.hasMoreElements()) {
   String sessionName = iSession.nextElement();
   Object sessionValue = session.getAttribute(sessionName);

   valueMap.put(sessionName, sessionValue);
   logger.info("sessoin[{}]={}", sessionName, sessionValue);
   
   session.removeAttribute(sessionName);
  }
  
  return new ResponseEntity<Map<String, Object>>(valueMap, HttpStatus.OK);
 }

 /**
  * 执行跳转，并设置传值
  *
  * @param counter
  * @param response
  * @return
  */
 @GetMapping("/first")
 public String first(final RedirectAttributes redirectAttrs) {

  logger.info("redirect start:{}");

  redirectAttrs.addFlashAttribute("flash", UUID.randomUUID().toString());
  return "redirect:/flash/second";
 }

 /**
  * 获取传值
  * 
  * @param session
  * @param response
  * @return
  */
 @GetMapping("/second")
 @ResponseBody
 public String second(@ModelAttribute("flash") String flash) {

  logger.info("redirect receive {}", flash);
  return flash;
 }