我已经编写了一个看起来非常慢的程序，它需要花费很多分钟而不是几秒钟来从数据库中读取和写入数据。它似乎在我的 runComparisons 方法中放慢了很多，但我不确定我应该采取哪些步骤来纠正这个问题。
public static void runComparisons(String industryTitle, List<String> tickerName, TradingInterval tradingInterval) throws SQLException {
// Get primary performance values ticker return
for (String ticker : tickerName) {
String startDate = tradingInterval.beginDate;
//System.out.println("start date " + startDate);
String endDate = tradingInterval.endDate;
//System.out.println("end date " + endDate);
PreparedStatement statement = conn.prepareStatement
("select P.TransDate, P.openPrice, P.closePrice" +
" from PriceVolume P" +
" where Ticker = ? and TransDate>= ? and TransDate <= ?" +
"order by TransDate DESC");
statement.setString(1, ticker);
statement.setString(2, startDate);
statement.setString(3, endDate);
ResultSet result = statement.executeQuery();
String date;
double nextOpenPrice = 0.0;
double currentClosePrice;
//int numberDays = 1;
//int splitCounter = 0;
double divideAmount = 1;
String tickerSymbol = "";
// create list to contain dates for use in investment strategy
ArrayList<holdSplitVals> ascendingList = new ArrayList<>();
// process result set
while (result.next()) {
//tickerSymbol = result.getString("Ticker");
// reset split amount for next iteration
date = result.getString("TransDate");
double openPrice = result.getDouble("OpenPrice");
double closePrice = result.getDouble("ClosePrice");
currentClosePrice = closePrice;
// get closing/opening ratio
double splitAmount = getRatios(date, nextOpenPrice, currentClosePrice);
if (splitAmount > 0) {
divideAmount = divideAmount * splitAmount;
//splitCounter++;
}
// hold data in helper class
holdSplitVals data = new holdSplitVals();
data.date = date;
data.openPrice = openPrice / divideAmount;
data.closePrice = closePrice / divideAmount;
ascendingList.add(0, data);
nextOpenPrice = openPrice;
if (ascendingList.size() >= 1) {
outputTable(closePrice, openPrice, industryTitle, tickerSymbol, startDate, endDate);
}
}
}
}
private static void outputTable(double closePrice, double openPrice, String industryTitle, String tickerSymbol, String startDate, String endDate) throws SQLException {
double tickerNumber = (closePrice / openPrice) - 1;
DecimalFormat df = new DecimalFormat("#.####");
df.setRoundingMode(RoundingMode.CEILING);
String tickerNum = df.format(tickerNumber);
PreparedStatement writeStatement = writerconn.prepareStatement(
"insert into Performance(Industry, Ticker, StartDate, EndDate, TickerReturn)"
+ "values(?, ?, ?, ?, ?)");
writeStatement.setString(1, industryTitle);
writeStatement.setString(2, tickerSymbol);
writeStatement.setString(3, startDate);
writeStatement.setString(4, endDate);
writeStatement.setString(5, tickerNum);
writeStatement.executeUpdate();
}
private static double getRatios(String date, double nextOpenPrice, double currentClosePrice) {
double coRatio = currentClosePrice / nextOpenPrice;
// calculate splits
// for 2:1 split
if (Math.abs(coRatio - 2.0) < 0.20) {
//splitCounter++;
//splitDate = ("2:1 split on " + date);
//System.out.println("2:1 split on " + date + " " + currentClosePrice + "--> " + nextOpenPrice);
return 2.0;
// for 3:1 split
} else if (Math.abs(coRatio - 3.0) < 0.20) {
//splitCounter++;
//splitDate = ("3:1 split on "+ date);
//System.out.println("3:1 split on " + date + " " + currentClosePrice + "--> " + nextOpenPrice);
return 3.0;
// for 3:2 split
} else if (Math.abs(coRatio - 1.5) < 0.15) {
//splitCounter++;
//splitDate = ("3:2 split on " + date);
//System.out.println("3:2 split on " + date + " " + currentClosePrice + "--> " + nextOpenPrice);
return 1.5;
}
return 0;
}
}