Files
ma1sd/src/main/java/io/kamax/mxisd/util/GsonParser.java
2017-09-25 05:53:07 +02:00

105 lines
3.5 KiB
Java

/*
* mxisd - Matrix Identity Server Daemon
* Copyright (C) 2017 Maxime Dor
*
* https://max.kamax.io/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package io.kamax.mxisd.util;
import com.google.gson.*;
import io.kamax.mxisd.exception.InvalidResponseJsonException;
import io.kamax.mxisd.exception.JsonMemberNotFoundException;
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpResponse;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Optional;
public class GsonParser {
private JsonParser parser = new JsonParser();
private Gson gson;
public GsonParser() {
this(new GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES).create());
}
public GsonParser(Gson gson) {
this.gson = gson;
}
public JsonObject parse(InputStream stream) throws IOException {
JsonElement el = parser.parse(IOUtils.toString(stream, StandardCharsets.UTF_8));
if (!el.isJsonObject()) {
throw new InvalidResponseJsonException("Response body is not a JSON object");
}
return el.getAsJsonObject();
}
public <T> T parse(HttpServletRequest req, Class<T> type) throws IOException {
return gson.fromJson(parse(req.getInputStream()), type);
}
public <T> T parse(HttpResponse res, Class<T> type) throws IOException {
return gson.fromJson(parse(res.getEntity().getContent()), type);
}
public Optional<JsonObject> parseOptional(HttpResponse res) {
try {
return Optional.of(parse(res.getEntity().getContent()));
} catch (IOException e) {
return Optional.empty();
}
}
public JsonObject parse(InputStream stream, String property) throws IOException {
JsonObject obj = parse(stream);
if (!obj.has(property)) {
throw new JsonMemberNotFoundException("Member " + property + " does not exist");
}
JsonElement el = obj.get(property);
if (!el.isJsonObject()) {
throw new InvalidResponseJsonException("Member " + property + " is not a JSON object");
}
return el.getAsJsonObject();
}
public <T> T parse(InputStream stream, String memberName, Class<T> type) throws IOException {
JsonObject obj = parse(stream, memberName);
return gson.fromJson(obj, type);
}
public <T> T parse(HttpResponse res, String memberName, Class<T> type) throws IOException {
return parse(res.getEntity().getContent(), memberName, type);
}
public <T> Optional<T> parseOptional(HttpResponse res, String memberName, Class<T> type) throws IOException {
try {
return Optional.of(parse(res.getEntity().getContent(), memberName, type));
} catch (JsonMemberNotFoundException e) {
return Optional.empty();
}
}
}