baremaps-server-common/src/main/java/com/baremaps/server/common/BaseUriRequestFilter.java

/*
 * Copyright (C) 2020 The Baremaps 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
 *
 * 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 com.baremaps.server.common;

import java.io.IOException;
import javax.inject.Singleton;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.container.PreMatching;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.ext.Provider;

@Provider
@PreMatching
@Singleton
public class BaseUriRequestFilter implements ContainerRequestFilter {

  @Override
  public void filter(ContainerRequestContext requestContext) throws IOException {
    UriBuilder baseUri = UriBuilder.fromUri(requestContext.getUriInfo().getBaseUri());
    MultivaluedMap<String, String> headers = requestContext.getHeaders();
    if (headers.get("X-Forwarded-Proto") != null) {
      baseUri.scheme(headers.getFirst("X-Forwarded-Proto"));
    }
    if (headers.get("X-Forwarded-Host") != null) {
      baseUri.host(headers.getFirst("X-Forwarded-Host"));
    }
    if (headers.get("X-Forwarded-Port") != null) {
      baseUri.port(Integer.parseInt(headers.getFirst("X-Forwarded-Port")));
    }
    requestContext.setRequestUri(baseUri.build(), requestContext.getUriInfo().getRequestUri());
  }
}