这篇文章主要介绍“springboot中@component注解如何使用”，在日常操作中，相信很多人在springboot中@component注解如何使用问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”springboot中@component注解如何使用”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
@component注解的使用
配置响应头的内容。
方式一
直接在拦截器里配置响应头内容。
public class RestInterceptor implements HandlerInterceptor { private static final Logger log = LoggerFactory.getLogger(RestInterceptor.class); private static final String tokenHeader = "Authorization"; public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { log.info("拦截请求"); //响应头 response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Headers", "x-requested-with,content-type,authorization"); response.setHeader("Access-Control-Allow-Methods", "POST,GET,OPTIONS"); if(request.getMethod().equals("OPTIONS")){ response.setStatus(204); return true; } log.info("调用接口:method=" +request.getParameter("method")+",params="+JSON.toJSONString(request.getParameterMap())); // HandlerMethod handlerMethod = (HandlerMethod)handler;// RequestAuth requestAuth = handlerMethod.getMethodAnnotation(RequestAuth.class);// if(requestAuth!=null && requestAuth.auth()==false){ //非验证API // return true;//跳过验证// } //验证// String token = request.getHeader(tokenHeader);// if(token == null || token.equals("")) {// log.info("没有找到token");// throw new BusinessException(ResMsg.CODE_TOKEN_NOTFOUND, "没有找到token");// } else {// JWSObject jwsObject = JWSObject.parse(token);// Payload payload = jwsObject.getPayload();// JSONObject obj = payload.toJSONObject(); // String roleNames = String.valueOf(obj.get("roleNames"));// Authentication auth = new Authentication();// if(obj.containsKey("platformId")) {// Long platformId = Long.valueOf(String.valueOf(obj.get("platformId")));// auth.setPlatformId(platformId);// }// if(obj.containsKey("userid")) {// Long userId = Long.valueOf(String.valueOf(obj.get("userid")));// auth.setUserId(userId);// }// if(obj.containsKey("orgId")) {// Long orgId = Long.valueOf(String.valueOf(obj.get("orgId")));// auth.setOrgId(orgId);// }// if(obj.containsKey("orgid")) {//为兼容老版本的接口// String orgid = String.valueOf(obj.get("orgid"));// orgid = orgid.replace(",", "");// Long orgId = Long.valueOf(orgid);// auth.setOrgId(orgId);// }// auth.setRoleNames(roleNames);// SecurityContext.setContext(auth);// JwtUtil.verify(jwsObject);// } return true; } public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { //log.info("处理中"); } public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { if(ex != null) { log.error("接口处理异常:"+ex); throw ex; } }}方式二
使用@component注解，将普通JavaBean实例化到spring容器中。
public class RestInterceptor implements HandlerInterceptor { private static final Logger log = LoggerFactory.getLogger(RestInterceptor.class); private static final String tokenHeader = "Authorization"; public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { log.info("拦截请求"); if(request.getMethod().equals("OPTIONS")){ response.setStatus(204); return true; } log.info("调用接口:method=" +request.getParameter("method")+",params="+JSON.toJSONString(request.getParameterMap())); return true; } public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { //log.info("处理中"); } public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { if(ex != null) { log.error("接口处理异常:"+ex); throw ex; } }}定义 SimpleCORSFilter.java 类, 使用@component注解
@Componentpublic class SimpleCORSFilter implements Filter { public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) res; response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "x-requested-with,content-type,authorization"); chain.doFilter(req, res); } public void init(FilterConfig filterConfig) {} public void destroy() {} }两种方式都可以完成响应。
@component注解有什么作用
用一句话概括
被@Component注解标识的类，会被纳入Spring容器中统一管理，好处是什么？一句话概括：你不用自己new了！
到此，关于“springboot中@component注解如何使用”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注编程网网站，小编会继续努力为大家带来更多实用的文章！
