omega/omega-transport/omega-transport-resttemplate/src/main/java/org/apache/servicecomb/pack/omega/transport/resttemplate/TransactionClientHttpRequestInterceptor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 *
 *      http://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 org.apache.servicecomb.pack.omega.transport.resttemplate;

import static org.apache.servicecomb.pack.omega.context.OmegaContext.GLOBAL_TX_ID_KEY;
import static org.apache.servicecomb.pack.omega.context.OmegaContext.LOCAL_TX_ID_KEY;

import java.io.IOException;
import java.lang.invoke.MethodHandles;

import org.apache.servicecomb.pack.omega.context.OmegaContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;

class TransactionClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {
  private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  private final OmegaContext omegaContext;

  TransactionClientHttpRequestInterceptor(OmegaContext omegaContext) {
    this.omegaContext = omegaContext;
  }

  @Override
  public ClientHttpResponse intercept(HttpRequest request, byte[] body,
      ClientHttpRequestExecution execution) throws IOException {

    if (omegaContext!= null && omegaContext.globalTxId() != null) {
      request.getHeaders().add(GLOBAL_TX_ID_KEY, omegaContext.globalTxId());
      request.getHeaders().add(LOCAL_TX_ID_KEY, omegaContext.localTxId());

      LOG.debug("Added {} {} and {} {} to request header",
          GLOBAL_TX_ID_KEY,
          omegaContext.globalTxId(),
          LOCAL_TX_ID_KEY,
          omegaContext.localTxId());
    } else {
      LOG.debug("Cannot inject transaction ID, as the OmegaContext is null or cannot get the globalTxId.");
    }
    return execution.execute(request, body);
  }
}