com.ifengxue.http.codec.CodecFactory Maven / Gradle / Ivy

/*
 * Copyright 2019 https://www.ifengxue.com
 *
 * 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.ifengxue.http.codec;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;

/**
 * codec factory
 */
public final class CodecFactory {

  private static final Map, Codec> codecCache = new ConcurrentHashMap<>();
  private static final List codecs = new ArrayList<>();

  static {
    registerCodec(new FastjsonJsonCodec());
  }

  /**
   * register new or replace old codec
   */
  public static synchronized void registerCodec(Codec codec) {
    codecCache.put(codec.getClass(), codec);
    codecs.add(codec);
  }

  /**
   * find codec by codec class
   */
  @SuppressWarnings("unchecked")
  public static  T findCodec(Class codecClass) {
    Codec codec = codecCache.computeIfAbsent(codecClass, clazz -> {
      for (Codec c : codecs) {
        if (codecClass.isAssignableFrom(c.getClass())) {
          return c;
        }
      }
      return null;
    });
    return (T) Optional.ofNullable(codec)
        .orElseThrow(() -> new NoSuchElementException("codec type " + codecClass.getName() + " can't be found."));
  }
}