content: /*
   * Copyright 2013-2023 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.cloud.seata.web;
  
  import io.seata.common.util.StringUtils;
  import io.seata.core.context.RootContext;
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.springframework.web.servlet.HandlerInterceptor;
  
  /**
   * @author xiaojing
   *
   * Seata HandlerInterceptor, Convert Seata information into
   * @see io.seata.core.context.RootContext from http request's header in
   * {@link org.springframework.web.servlet.HandlerInterceptor#preHandle(HttpServletRequest, HttpServletResponse, Object)},
   * And clean up Seata information after servlet method invocation in
   * {@link org.springframework.web.servlet.HandlerInterceptor#afterCompletion(HttpServletRequest, HttpServletResponse, Object, Exception)}
   */
  public class SeataHandlerInterceptor implements HandlerInterceptor {
  
  	private static final Logger log = LoggerFactory
  			.getLogger(SeataHandlerInterceptor.class);
  
  	@Override
  	public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
  			Object handler) {
  		String xid = RootContext.getXID();
  		String rpcXid = request.getHeader(RootContext.KEY_XID);
  		if (log.isDebugEnabled()) {
  			log.debug("xid in RootContext {} xid in RpcContext {}", xid, rpcXid);
  		}
  
  		if (StringUtils.isBlank(xid) && rpcXid != null) {
  			RootContext.bind(rpcXid);
  			if (log.isDebugEnabled()) {
  				log.debug("bind {} to RootContext", rpcXid);
  			}
  		}
  
  		return true;
  	}
  
  	@Override
  	public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
  			Object handler, Exception e) {
  		if (StringUtils.isNotBlank(RootContext.getXID())) {
  			String rpcXid = request.getHeader(RootContext.KEY_XID);
  
  			if (StringUtils.isEmpty(rpcXid)) {
  				return;
  			}
  
  			String unbindXid = RootContext.unbind();
  			if (log.isDebugEnabled()) {
  				log.debug("unbind {} from RootContext", unbindXid);
  			}
  			if (!rpcXid.equalsIgnoreCase(unbindXid)) {
  				log.warn("xid in change during RPC from {} to {}", rpcXid, unbindXid);
  				if (unbindXid != null) {
  					RootContext.bind(unbindXid);
  					log.warn("bind {} back to RootContext", unbindXid);
  				}
  			}
  		}
  	}
  
  }
  