gson-comments/gson/src/main/java/com/google/gson/internal/bind/NumberTypeAdapter.java

83 lines
2.7 KiB
Java

/*
* Copyright (C) 2020 Google Inc.
*
* 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.google.gson.internal.bind;
import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;
import com.google.gson.ToNumberPolicy;
import com.google.gson.ToNumberStrategy;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
/** Type adapter for {@link Number}. */
public final class NumberTypeAdapter extends TypeAdapter<Number> {
/** Gson default factory using {@link ToNumberPolicy#LAZILY_PARSED_NUMBER}. */
private static final TypeAdapterFactory LAZILY_PARSED_NUMBER_FACTORY =
newFactory(ToNumberPolicy.LAZILY_PARSED_NUMBER);
private final ToNumberStrategy toNumberStrategy;
private NumberTypeAdapter(ToNumberStrategy toNumberStrategy) {
this.toNumberStrategy = toNumberStrategy;
}
private static TypeAdapterFactory newFactory(ToNumberStrategy toNumberStrategy) {
final NumberTypeAdapter adapter = new NumberTypeAdapter(toNumberStrategy);
return new TypeAdapterFactory() {
@SuppressWarnings("unchecked")
@Override
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
return type.getRawType() == Number.class ? (TypeAdapter<T>) adapter : null;
}
};
}
public static TypeAdapterFactory getFactory(ToNumberStrategy toNumberStrategy) {
if (toNumberStrategy == ToNumberPolicy.LAZILY_PARSED_NUMBER) {
return LAZILY_PARSED_NUMBER_FACTORY;
} else {
return newFactory(toNumberStrategy);
}
}
@Override
public Number read(JsonReader in) throws IOException {
JsonToken jsonToken = in.peek();
switch (jsonToken) {
case NULL:
in.nextNull();
return null;
case NUMBER:
case STRING:
return toNumberStrategy.readNumber(in);
default:
throw new JsonSyntaxException(
"Expecting number, got: " + jsonToken + "; at path " + in.getPath());
}
}
@Override
public void write(JsonWriter out, Number value) throws IOException {
out.value(value);
}
}