com.google.cloud.examples.coinflow.frontend.CoinflowServlet.java Source code

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Here is the source code for com.google.cloud.examples.coinflow.frontend.CoinflowServlet.java

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/*
 * Copyright (c) 2015 Google Inc. 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.google.cloud.examples.coinflow.frontend;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;
import com.google.cloud.examples.coinflow.data.CoinbaseData;
import com.google.cloud.examples.coinflow.data.Schema;
import com.google.cloud.examples.coinflow.utils.DateHelpers;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class CoinflowServlet extends HttpServlet {
    private static final TableName TABLE = TableName.valueOf("coinbase");

    private static final Logger LOG = LoggerFactory.getLogger(CoinflowServlet.class);

    private static class PriceTimestamp {

        public PriceTimestamp(float price, long timestamp) {
            this.price = price;
            this.timestamp = timestamp;
        }

        public final float price;
        public final long timestamp;
    }

    private ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        LOG.info("In CoinflowServlet doGet");

        if (req.getRequestURI().equals("/favicon.ico"))
            return;

        try (Table t = BigtableHelper.getConnection().getTable(TABLE)) {

            DateTime dateTime = new DateTime().minusHours(4);
            long before_ts = dateTime.getMillis();
            long now_ts = new DateTime().getMillis();

            String beforeRowKey = "match_" + before_ts;
            String afterRowKey = "match_" + now_ts;

            Scan scan = new Scan(beforeRowKey.getBytes(), afterRowKey.getBytes());
            ResultScanner rs = t.getScanner(scan);
            resp.addHeader("Access-Control-Allow-Origin", "*");
            resp.setContentType("text/plain");

            List<PriceTimestamp> prices = new ArrayList<>();
            for (Result r : rs) {
                String data = new String(r.getValue(Schema.CF.getBytes(), Schema.QUALIFIER.getBytes()));
                CoinbaseData coinData = objectMapper.readValue(data, CoinbaseData.class);
                PriceTimestamp priceTimestamp = new PriceTimestamp(Float.parseFloat(coinData.getPrice()),
                        DateHelpers.convertDateToTime(coinData.getTime()));
                prices.add(priceTimestamp);
            }
            String pricesStr = objectMapper.writeValueAsString(prices);
            resp.getWriter().println(pricesStr);
        }

    }
}