org.springframework.http.converter.json.GsonBuilderUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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
*
* https://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.springframework.http.converter.json;
import java.lang.reflect.Type;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import org.springframework.util.Base64Utils;
/**
* A simple utility class for obtaining a Google Gson 2.x {@link GsonBuilder}
* which Base64-encodes {@code byte[]} properties when reading and writing JSON.
*
* @author Juergen Hoeller
* @author Roy Clarkson
* @since 4.1
* @see GsonFactoryBean#setBase64EncodeByteArrays
* @see org.springframework.util.Base64Utils
*/
public abstract class GsonBuilderUtils {
/**
* Obtain a {@link GsonBuilder} which Base64-encodes {@code byte[]}
* properties when reading and writing JSON.
* A custom {@link com.google.gson.TypeAdapter} will be registered via
* {@link GsonBuilder#registerTypeHierarchyAdapter(Class, Object)} which
* serializes a {@code byte[]} property to and from a Base64-encoded String
* instead of a JSON array.
*/
public static GsonBuilder gsonBuilderWithBase64EncodedByteArrays() {
GsonBuilder builder = new GsonBuilder();
builder.registerTypeHierarchyAdapter(byte[].class, new Base64TypeAdapter());
return builder;
}
private static class Base64TypeAdapter implements JsonSerializer, JsonDeserializer {
@Override
public JsonElement serialize(byte[] src, Type typeOfSrc, JsonSerializationContext context) {
return new JsonPrimitive(Base64Utils.encodeToString(src));
}
@Override
public byte[] deserialize(JsonElement json, Type type, JsonDeserializationContext cxt) {
return Base64Utils.decodeFromString(json.getAsString());
}
}
}