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/*
 * Copyright (c) 2010-2015 Pivotal Software, 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. See accompanying
 * LICENSE file.
 */
package flashcache;

import com.gemstone.gemfire.cache.CacheLoader;
import com.gemstone.gemfire.cache.LoaderHelper;
import com.gemstone.gemfire.cache.Region;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;

/** 
 * This class implements a CacheLoader used by the Quote program to
 * search for quotes in other caches and, failing that, to pull quotes
 * from the NASDAQ FlashQuote web site.
 *
 * 

 *
 * When a CacheLoader is associated with a {@link
 * Region}, GemFire will use it to load requested objects when there
 * is a cache-miss.
 *
 * @author GemStone Systems, Inc.
 *
 * @since 2.0
 */
public class QuoteLoader implements CacheLoader
{

/** this method is invoked by GemFire when there is a cache miss */
public Object load(LoaderHelper helper)
{
  String key = helper.getKey();  // the name of the cache entry

  // first check other caches but don't invoke their CacheLoaders
  System.out.println("(QuoteLoader netSearching for " + key + ")");
  try {
  Object hit = helper.netSearch(false);
    if (hit != null) {
      return hit;
    } 
  }
  catch (Exception e) {
    System.out.println(e.toString());
  }

  // now query quote.nasdaq.com
  System.out.println("(QuoteLoader querying nasdaq for " + key + ")");
  return loadSnapshot(key);
}

/** this method is invoked by the load() method when the requested quote
    isn't in the cache system and must be loaded from the NASDAQ web site */
String loadSnapshot(String symbolToLoad) {
  String page = "";
  String symbol = symbolToLoad;
  try {
    InputStream result;
    InputStreamReader reader;
    char[] buffer = new char[100000];
    int numchars;
    
    if (symbol == null)
      symbol = "JAVA";

    // the following code queries the quotes.nasdaq.com service and 
    // parses out the information needed to form the quote.  There is
    // retry logic in case nasdaq fails to respond

    boolean done = false;
    int maxTries = 4;
    for (int tries=0; !done && (tries < maxTries); tries++) {

      // note that nasdaq may charge for quote lookup services
      
      if (tries > 0) {
        page = "";  // reset the received portion of the web page
      }

      URL lookupURL = new URL(
        "http://quotes.nasdaq.com/quote.dll?page=quick&mode=stock&symbol="
        + symbol
        );
    
    
      String endTag = "";
      result = lookupURL.openStream();
      reader = new InputStreamReader(result);
      try {
        int innerloops = 0;
        do {
          innerloops++;
          for (int i=0; i<100; i++) {
            if (result.available() > 0) {
              break;
            }
            try { Thread.sleep(100); } catch (InterruptedException e) { break; }
          }
          if (result.available() > 0) {
            numchars = reader.read(buffer, 0, buffer.length);
            page = page + new String(buffer, 0, numchars);
          }
          done = page.indexOf(endTag, Math.max(page.length() - 100, 0)) > 0;
        } while (innerloops <= 100 && !done);
      }
      finally {
        result.close();
        reader.close();
      }
      
    } // for (tries)

    if (!done) {
      System.out.println("nasdaq did not respond in " + maxTries + " attempts.  Loader is returning null");
      return null;
    }

    String answer = symbol + ":";
    int idx = page.indexOf("symbol="+symbol);
    if (idx < 0) {
      return answer + "(invalid symbol)";
    } 

    idx = page.indexOf(" ", idx+10) + 6;
    int idx2 = page.indexOf("<", idx);
    answer = answer + " last sale=" + page.substring(idx, idx2);

    String netChange = null;
    idx = page.indexOf("color:", idx2+1);
    idx2 = page.indexOf("\"", idx+6);
    String color = "unknown";
    
    if (idx > 0 && idx2 > 0) {
      color = page.substring(idx+6, idx2);
    }
    
    if (color.equals("green")) {
      idx = page.indexOf(" ", idx2) + 6;
      idx2 = page.indexOf(" ", idx) - 1;
      netChange = "+" + page.substring(idx, idx2);
    }
    else if (color.equals("red")) {
      idx = page.indexOf(" ", idx2) + 6;
      idx2 = page.indexOf(" ", idx) - 1;
      netChange = "-" + page.substring(idx, idx2);
    }
    else {
      netChange = "unch";
    }

    answer = answer + "  net change=" + netChange;
    
    idx = page.indexOf("volume\">", idx2+1) + 8;
    idx2 = page.indexOf("<", idx);
    answer = answer + "  volume=" + page.substring(idx, idx2);
    
    return answer;
  }
  catch (Exception e) {
    e.printStackTrace();
    //return page;
    return symbol+": not found";
  }
}

/** This method would clean up any database connections or other 
  * external resources.
  */
  public void close() {

  }

/** This is a test driver - this loads a quote without looking in
  * the GemFire cache.

  * The class {@link Quote} uses GemFire to cache quotes.
  */
public static void main(String args[]) {
  if (args.length < 1) {
    System.out.println("java examples.flashcache.QuoteLoader [symbol]*");
    System.exit(1);
  }
  QuoteLoader instance = new QuoteLoader();
  for (int i=0; i




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