多线程获取yahoo股票信息

首先给到需要获取和计算的股票，存入一个文本中，如stocks.txt

01

AAPL,2505

02

AMGN,3406

03

AMZN,9354

04

BAC,9839

05

BMY,5099

06

CAT,8463

07

C,1500

08	CMCSA,6144

09

CSCO,4589

10

CVX,9696

11

DIS,4804

12

DOW,3654

13

EMC,4835

14

FDX,4753

15

GD,3919

16

GE,7003

17

GOOG,6631

18

HAL,2593

19

HPQ,6157

20

IBM,1728

21

INTC,4053

22

JPM,1665

23

LMT,4402

24

MET,3712

25

MO,3764

26

MSFT,2813

27

NKE,6447

28

NSC,5537

29

ORCL,7136

30

PFE,659

31

RTN,5063

32

S,8219

33

SO,7175

34

TXN,1410

35

USB,3099

36

VZ,9826

37

WMT,6478

然后定义个抽象类，用于读取这个stocks.txt中存放的股票信息，并计算出股票的总值和读取花费的时间。代码如下：

01	publicabstractclassAbstractNAV{

02	publicstaticMap<String,Integer>readTickers()throwsIOException{

03	finalBufferedReaderreader=

04	newBufferedReader(newFileReader("d:/stocks.txt"));

05

06	finalMap<String,Integer>stocks=newHashMap<String,Integer>();

07

08	StringstockInfo=null;

09	while((stockInfo=reader.readLine())!=null){

10	finalString[]stockInfoData=stockInfo.split(",");

11	finalStringstockTicker=stockInfoData[0];

12	finalIntegerquantity=Integer.valueOf(stockInfoData[1]);

13

14	stocks.put(stockTicker,quantity);

15

}

16

17	returnstocks;

18

}

19

20	publicvoidtimeAndComputeValue()

21	throwsExecutionException,InterruptedException,IOException{

22	finallongstart=System.nanoTime();

23

24	finalMap<String,Integer>stocks=readTickers();

25	finaldoublenav=computeNetAssetValue(stocks);

26

27	finallongend=System.nanoTime();

28

29	finalStringvalue=newDecimalFormat("$##,##0.00").format(nav);

30	System.out.println("Yournetassetvalueis"+value);

31	System.out.println("Time(seconds)taken"+(end-start)/1.0e9);

32

}

33

34	publicabstractdoublecomputeNetAssetValue(

35	finalMap<String,Integer>stocks)

36	throwsExecutionException,InterruptedException,IOException;

37

}

然后，我们用传统的单线程方式，依次去读取并计算股票，并打印总价和花费的时间，代码如下：

01	publicclassSequentialNAVextendsAbstractNAV{

02	publicdoublecomputeNetAssetValue(

03	finalMap<String,Integer>stocks)throwsIOException{

04	doublenetAssetValue=0.0;

05	for(Stringticker:stocks.keySet()){

06	netAssetValue+=stocks.get(ticker)*YahooFinance.getPrice(ticker);

07

}

08	returnnetAssetValue;

09

}

10

11	publicstaticvoidmain(finalString[]args)

12	throwsExecutionException,IOException,InterruptedException{

13	newSequentialNAV().timeAndComputeValue();

14

}

15

}

由于网络问题，我这里运行之后，得到的结果是：

1	Yournetassetvalueis$18,317,338.21

2	Time(seconds)taken18.080151543

紧接着，我们用多线程方式，读取并计算，并打印总价和时间花费

01	publicclassConcurrentNAVextendsAbstractNAV{

02	publicdoublecomputeNetAssetValue(finalMap<String,Integer>stocks)

03	throwsInterruptedException,ExecutionException{

04	finalintnumberOfCores=Runtime.getRuntime().availableProcessors();

05	finaldoubleblockingCoefficient=0.9;

06	finalintpoolSize=(int)(numberOfCores/(1-blockingCoefficient));

07

08	System.out.println("NumberofCoresavailableis"+numberOfCores);

09	System.out.println("Poolsizeis"+poolSize);

10	//Callable接口的实例，用于被另一个线程执行call()，并返回，无返回则抛出异常。

11	//它类似于Runnable接口，而Runnable不会返回结果，并且无法抛出经过检查的异常。

12	finalList<Callable<Double>>partitions=

13	newArrayList<Callable<Double>>();

14	for(finalStringticker:stocks.keySet()){

15	partitions.add(newCallable<Double>(){

16	publicDoublecall()throwsException{

17	returnstocks.get(ticker)*YahooFinance.getPrice(ticker);

18

}

19

});

20

}

21

22

//定义线程池

23	finalExecutorServiceexecutorPool=

24	Executors.newFixedThreadPool(poolSize);

25	//Future接口的实例，通过get()方法，获取多线程下异步的计算结果。

26	//必要时，计算完成前可阻塞该方法，可通过cancel()取消计算，一旦计算完成，则无法取消。

27	finalList<Future<Double>>valueOfStocks=

28	executorPool.invokeAll(partitions,10000,TimeUnit.SECONDS);

29

30	doublenetAssetValue=0.0;

31	for(finalFuture<Double>valueOfAStock:valueOfStocks)

32	netAssetValue+=valueOfAStock.get();

33

34	executorPool.shutdown();

35	returnnetAssetValue;

36

}

37

38	publicstaticvoidmain(finalString[]args)

39	throwsExecutionException,InterruptedException,IOException{

40	newConcurrentNAV().timeAndComputeValue();

41

}

42

}

在跟上面同等的网络环境下，这段代码运行之后的结果为：

1	NumberofCoresavailableis4

2	Poolsizeis40

3	Yournetassetvalueis$18,317,338.21

4	Time(seconds)taken0.715660335