/**
* This file is part of lavagna.
*
* lavagna is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* lavagna is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with lavagna. If not, see <http://www.gnu.org/licenses/>.
*/
package io.lavagna.web.helper;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonSyntaxException;
import io.lavagna.common.Constants;
import io.lavagna.common.Json;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.Date;
/**
*
* Read/write json, derived from :
* <ul>
* <li>http://stackoverflow.com/a/5099622
* <li>http://stackoverflow.com/a/8728500
* </ul>
*
* Used as a lightweight alternative to jackson.
*/
public class GsonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {
private final Gson gson = new GsonBuilder().serializeNulls().setDateFormat(Constants.DATE_FORMAT)
.registerTypeHierarchyAdapter(Date.class, new Json.CustomDateSerializer())
.generateNonExecutableJson().create();
public GsonHttpMessageConverter() {
super(new MediaType("application", "json", StandardCharsets.UTF_8));
}
@Override
protected boolean supports(Class<?> clazz) {
return true;
}
@Override
protected Object readInternal(Class<? extends Object> clazz, HttpInputMessage inputMessage) throws IOException {
try (Reader reader = new InputStreamReader(inputMessage.getBody(), StandardCharsets.UTF_8)) {
return gson.fromJson(reader, clazz);
} catch (JsonSyntaxException e) {
throw new HttpMessageNotReadableException("Could not read JSON: " + e.getMessage(), e);
}
}
@Override
protected void writeInternal(Object t, HttpOutputMessage outputMessage) throws IOException {
try (Writer writer = new OutputStreamWriter(outputMessage.getBody(), StandardCharsets.UTF_8)) {
gson.toJson(t, writer);
}
}
}