org.springframework.messaging.converter.GsonMessageConverter Maven / Gradle / Ivy
/*
* Copyright 2002-2020 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.messaging.converter;
import java.io.Reader;
import java.io.Writer;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import com.google.gson.Gson;
import org.springframework.util.Assert;
/**
* Implementation of {@link MessageConverter} that can read and write JSON
* using Google Gson.
*
* @author Juergen Hoeller
* @since 5.3
* @see com.google.gson.Gson
* @see com.google.gson.GsonBuilder
* @see #setGson
*/
public class GsonMessageConverter extends AbstractJsonMessageConverter {
private Gson gson;
/**
* Construct a new {@code GsonMessageConverter} with default configuration.
*/
public GsonMessageConverter() {
this.gson = new Gson();
}
/**
* Construct a new {@code GsonMessageConverter} with the given delegate.
* @param gson the Gson instance to use
*/
public GsonMessageConverter(Gson gson) {
Assert.notNull(gson, "A Gson instance is required");
this.gson = gson;
}
/**
* Set the {@code Gson} instance to use.
* If not set, a default {@link Gson#Gson() Gson} instance will be used.
* Setting a custom-configured {@code Gson} is one way to take further
* control of the JSON serialization process.
* @see #GsonMessageConverter(Gson)
*/
public void setGson(Gson gson) {
Assert.notNull(gson, "A Gson instance is required");
this.gson = gson;
}
/**
* Return the configured {@code Gson} instance for this converter.
*/
public Gson getGson() {
return this.gson;
}
@Override
protected Object fromJson(Reader reader, Type resolvedType) {
return getGson().fromJson(reader, resolvedType);
}
@Override
protected Object fromJson(String payload, Type resolvedType) {
return getGson().fromJson(payload, resolvedType);
}
@Override
protected void toJson(Object payload, Type resolvedType, Writer writer) {
if (resolvedType instanceof ParameterizedType) {
getGson().toJson(payload, resolvedType, writer);
}
else {
getGson().toJson(payload, writer);
}
}
@Override
protected String toJson(Object payload, Type resolvedType) {
if (resolvedType instanceof ParameterizedType) {
return getGson().toJson(payload, resolvedType);
}
else {
return getGson().toJson(payload);
}
}
}