ContentTypeResolver.java

/*
 * Copyright 2022 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
 *
 *      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.bremersee.apiclient.webflux.contract.spring;

import java.util.Arrays;
import java.util.Optional;
import java.util.function.Function;
import org.bremersee.apiclient.webflux.Invocation;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PatchMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * The content type resolver.
 *
 * @author Christian Bremer
 */
public class ContentTypeResolver implements Function<Invocation, Optional<MediaType>> {

  @Override
  public Optional<MediaType> apply(Invocation invocation) {
    return Arrays.stream(
            invocation.findAnnotationValueOnMethod(
                    RequestMapping.class, a -> a.consumes().length > 0, RequestMapping::consumes)
                .or(() -> invocation.findAnnotationValueOnMethod(
                    GetMapping.class, a -> a.consumes().length > 0, GetMapping::consumes))
                .or(() -> invocation.findAnnotationValueOnMethod(
                    PostMapping.class, a -> a.consumes().length > 0, PostMapping::consumes))
                .or(() -> invocation.findAnnotationValueOnMethod(
                    PutMapping.class, a -> a.consumes().length > 0, PutMapping::consumes))
                .or(() -> invocation.findAnnotationValueOnMethod(
                    PatchMapping.class, a -> a.consumes().length > 0, PatchMapping::consumes))
                .or(() -> invocation.findAnnotationValueOnMethod(
                    DeleteMapping.class, a -> a.consumes().length > 0, DeleteMapping::consumes))
                .orElse(new String[0]))
        .map(this::parseMediaType)
        .filter(MediaType::isConcrete)
        .findFirst();
  }

  /**
   * Parse media type.
   *
   * @param mediaType the media type
   * @return the media type (can be {@code null})
   */
  protected MediaType parseMediaType(String mediaType) {
    try {
      return MediaType.parseMediaType(mediaType);
    } catch (RuntimeException ignored) {
      return null;
    }
  }
}