gson-comments/extras/src/main/java/com/google/gson/interceptors/InterceptorFactory.java

67 lines
2.1 KiB
Java

/*
* Copyright (C) 2012 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.interceptors;
import com.google.gson.Gson;
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.JsonWriter;
import java.io.IOException;
/** A type adapter factory that implements {@code @Intercept}. */
public final class InterceptorFactory implements TypeAdapterFactory {
@Override
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
Intercept intercept = type.getRawType().getAnnotation(Intercept.class);
if (intercept == null) {
return null;
}
TypeAdapter<T> delegate = gson.getDelegateAdapter(this, type);
return new InterceptorAdapter<>(delegate, intercept);
}
static class InterceptorAdapter<T> extends TypeAdapter<T> {
private final TypeAdapter<T> delegate;
private final JsonPostDeserializer<T> postDeserializer;
@SuppressWarnings("unchecked") // ?
public InterceptorAdapter(TypeAdapter<T> delegate, Intercept intercept) {
try {
this.delegate = delegate;
this.postDeserializer = intercept.postDeserialize().getDeclaredConstructor().newInstance();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
@Override
public void write(JsonWriter out, T value) throws IOException {
delegate.write(out, value);
}
@Override
public T read(JsonReader in) throws IOException {
T result = delegate.read(in);
postDeserializer.postDeserialize(result);
return result;
}
}
}