code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC 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.openqa.selenium.json;
  
  import static java.util.stream.Collector.Characteristics.CONCURRENT;
  import static java.util.stream.Collector.Characteristics.UNORDERED;
  import static java.util.stream.Collectors.collectingAndThen;
  import static java.util.stream.Collectors.toSet;
  import static org.openqa.selenium.json.Types.narrow;
  
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.function.BiFunction;
  import java.util.stream.Collector;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  import java.util.stream.StreamSupport;
  import org.openqa.selenium.Capabilities;
  import org.openqa.selenium.MutableCapabilities;
  import org.openqa.selenium.internal.Require;
  
  class JsonTypeCoercer {
  
    private final Set<TypeCoercer<?>> additionalCoercers;
    private final Set<TypeCoercer<?>> coercers;
    private final Map<Type, BiFunction<JsonInput, PropertySetting, Object>> knownCoercers =
        new ConcurrentHashMap<>();
  
    JsonTypeCoercer() {
      this(Stream.of());
    }
  
    JsonTypeCoercer(JsonTypeCoercer coercer, Iterable<TypeCoercer<?>> coercers) {
      this(
          Stream.concat(
              StreamSupport.stream(coercers.spliterator(), false),
              coercer.additionalCoercers.stream()));
    }
  
    private JsonTypeCoercer(Stream<TypeCoercer<?>> coercers) {
      this.additionalCoercers =
          coercers.collect(collectingAndThen(toSet(), Collections::unmodifiableSet));
  
      // Note: we call out when ordering matters.
      Set<TypeCoercer<?>> builder = new LinkedHashSet<>(additionalCoercers);
  
      // Types that don't contain other types first
      // From java
      builder.add(new BooleanCoercer());
  
      builder.add(new NumberCoercer<>(Byte.class, Number::byteValue));
      builder.add(new NumberCoercer<>(Double.class, Number::doubleValue));
      builder.add(new NumberCoercer<>(Float.class, Number::floatValue));
      builder.add(new NumberCoercer<>(Integer.class, Number::intValue));
      builder.add(new NumberCoercer<>(Long.class, Number::longValue));
      builder.add(
          new NumberCoercer<>(
              Number.class,
              num -> {
                double doubleValue = num.doubleValue();
                if (doubleValue % 1 != 0 || doubleValue > Long.MAX_VALUE) {
                  return doubleValue;
                }
                return num.longValue();
              }));
      builder.add(new NumberCoercer<>(Short.class, Number::shortValue));
      builder.add(new StringCoercer());
      builder.add(new EnumCoercer<>());
      builder.add(new UriCoercer());
      builder.add(new UrlCoercer());
      builder.add(new UuidCoercer());
      builder.add(new InstantCoercer());
  
      // From Selenium
      builder.add(
          new MapCoercer<>(
              Capabilities.class,
              this,
              Collector.of(
                  MutableCapabilities::new,
                  (caps, entry) -> caps.setCapability((String) entry.getKey(), entry.getValue()),
                  MutableCapabilities::merge,
                  UNORDERED)));
  
      // Container types
      //noinspection unchecked
      builder.add(new CollectionCoercer<>(List.class, this, Collectors.toCollection(ArrayList::new)));
      //noinspection unchecked
      builder.add(new CollectionCoercer<>(Set.class, this, Collectors.toCollection(HashSet::new)));
  
      builder.add(new StaticInitializerCoercer());
  
      builder.add(
          new MapCoercer<>(
              Map.class,
              this,
              Collector.of(
                  LinkedHashMap::new,
                  (map, entry) -> map.put(entry.getKey(), entry.getValue()),
                  (l, r) -> {
                    l.putAll(r);
                    return l;
                  },
                  UNORDERED,
                  CONCURRENT)));
  
      // If the requested type is exactly "Object", do some guess work
      builder.add(new ObjectCoercer(this));
  
      // Order matters here: we want this to be the last called coercer
      builder.add(new InstanceCoercer(this));
  
      this.coercers = Collections.unmodifiableSet(builder);
    }
  
    <T> T coerce(JsonInput json, Type typeOfT, PropertySetting setter) {
      BiFunction<JsonInput, PropertySetting, Object> coercer =
          knownCoercers.computeIfAbsent(typeOfT, this::buildCoercer);
  
      // We need to keep null checkers happy, apparently.
      @SuppressWarnings("unchecked")
      T result = (T) Require.nonNull("Coercer", coercer).apply(json, setter);
  
      return result;
    }
  
    private BiFunction<JsonInput, PropertySetting, Object> buildCoercer(Type type) {
      return coercers.stream()
          .filter(coercer -> coercer.test(narrow(type)))
          .findFirst()
          .map(coercer -> coercer.apply(type))
          .map(
              func ->
                  (BiFunction<JsonInput, PropertySetting, Object>)
                      (jsonInput, setter) -> {
                        if (jsonInput.peek() == JsonType.NULL) {
                          return jsonInput.nextNull();
                        }
  
                        return func.apply(jsonInput, setter);
                      })
          .orElseThrow(() -> new JsonException("Unable to find type coercer for " + type));
    }
  }
  