com.datatorrent.demos.yahoofinance.YahooFinanceCSVInputOperator.java Source code

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Here is the source code for com.datatorrent.demos.yahoofinance.YahooFinanceCSVInputOperator.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.datatorrent.demos.yahoofinance;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.cookie.CookiePolicy;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.DefaultHttpParams;

import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.lib.io.SimpleSinglePortInputOperator;

import au.com.bytecode.opencsv.CSVReader;

/**
 * Grabs Yahoo Finance quotes data and emits HashMap, with key equals the format name (e.g. "s0") <p>
 *
 * @since 0.3.2
 */
public class YahooFinanceCSVInputOperator extends SimpleSinglePortInputOperator<HashMap<String, Object>>
        implements Runnable {
    private static final Logger logger = LoggerFactory.getLogger(YahooFinanceCSVInputOperator.class);
    /**
     * Timeout interval for reading from server. 0 or negative indicates no timeout.
     */
    private int readIntervalMillis = 500;

    /**
     * The URL of the web service resource for the POST request.
     */
    private String url;
    private transient HttpClient client;
    private transient GetMethod method;

    private ArrayList<String> symbolList = new ArrayList<String>();
    private ArrayList<String> parameterList = new ArrayList<String>();

    public void addSymbol(String symbol) {
        symbolList.add(symbol);
    }

    public void addFormat(String format) {
        parameterList.add(format);
    }

    public ArrayList<String> getSymbolList() {
        return symbolList;
    }

    public ArrayList<String> getParameterList() {
        return parameterList;
    }

    public int getReadIntervalMillis() {
        return readIntervalMillis;
    }

    public void setReadIntervalMillis(int readIntervalMillis) {
        this.readIntervalMillis = readIntervalMillis;
    }

    /**
     * Prepare URL from symbols and parameters.
     * URL will be something like: http://download.finance.yahoo.com/d/quotes.csv?s=GOOG,FB,YHOO&f=sl1vt1&e=.csv
     * @return
     */
    private String prepareURL() {
        String str = "http://download.finance.yahoo.com/d/quotes.csv?";

        str += "s=";
        for (int i = 0; i < symbolList.size(); i++) {
            if (i != 0) {
                str += ",";
            }
            str += symbolList.get(i);
        }
        str += "&f=";
        for (String format : parameterList) {
            str += format;
        }
        str += "&e=.csv";
        return str;
    }

    @Override
    public void setup(OperatorContext context) {
        url = prepareURL();
        client = new HttpClient();
        method = new GetMethod(url);
        DefaultHttpParams.getDefaultParams().setParameter("http.protocol.cookie-policy",
                CookiePolicy.BROWSER_COMPATIBILITY);
    }

    @Override
    public void run() {
        while (true) {
            try {
                int statusCode = client.executeMethod(method);
                if (statusCode != HttpStatus.SC_OK) {
                    logger.error("Method failed: " + method.getStatusLine());
                } else {
                    InputStream istream;
                    istream = method.getResponseBodyAsStream();
                    // Process response
                    InputStreamReader isr = new InputStreamReader(istream);
                    CSVReader reader = new CSVReader(isr);
                    List<String[]> myEntries;
                    myEntries = reader.readAll();
                    for (String[] stringArr : myEntries) {
                        HashMap<String, Object> hm = new HashMap<String, Object>();
                        for (int i = 0; i < parameterList.size(); i++) {
                            hm.put(parameterList.get(i), stringArr[i]);
                        }
                        outputPort.emit(hm); // send out one symbol at a time
                    }
                }
                Thread.sleep(readIntervalMillis);
            } catch (InterruptedException ex) {
                logger.debug(ex.toString());
            } catch (IOException ex) {
                logger.debug(ex.toString());
            }
        }
    }
}