com.d3x.morpheus.json.JsonSourceColumns Maven / Gradle / Ivy
/*
* Copyright (C) 2014-2018 D3X Systems - All Rights Reserved
*
* 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.d3x.morpheus.json;
import java.io.InputStreamReader;
import com.d3x.morpheus.frame.DataFrame;
import com.d3x.morpheus.frame.DataFrameException;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
/**
* A JsonSource implementation that can load a DataFrame from Pandas compatible JSON with "columns" orientation
*
* This is open source software released under the Apache 2.0 License
*
* @author Xavier Witdouck
*/
class JsonSourceColumns implements JsonSource {
private JsonReader reader;
@Override
public synchronized DataFrame read(Options options) throws DataFrameException {
try {
this.reader = new JsonReader(new InputStreamReader(options.getResource().toInputStream()));
this.reader.beginObject();
while (reader.hasNext()) {
final String name = reader.nextName();
final C colKey = options.getColKeyParser().apply(name);
this.reader.beginObject();
while (true) {
final JsonToken token = reader.peek();
if (token == JsonToken.END_OBJECT) {
reader.endObject();
break;
} else if (token == JsonToken.NAME) {
final String rowLabel = reader.nextName();
final R rowKey = options.getRowKeyParser().apply(rowLabel);
} else {
switch (token) {
case NAME: break;
case BOOLEAN: break;
case NUMBER: break;
case STRING: break;
case NULL: break;
}
}
}
}
reader.endObject();
return null;
} catch (Exception ex) {
throw new DataFrameException("Failed to load DataFrame from JSON: " + options, ex);
}
}
}