Question

Currently, I try to get the data through YQL.

select * from yahoo.finance.quotes where symbol in ("BP")

I will get the XML respond.

I was wondering, in my Java application, is there any common used library I can use to parse the XML?

Or should I request the respond to be in JSON format? Then use JSONObject to parse it? Which one will be easier?

Here is the XML respond.

<?xml version="1.0" encoding="UTF-8"?>
<query xmlns:yahoo="http://www.yahooapis.com/v1/base.rng"
    yahoo:count="1" yahoo:created="2010-09-16T05:00:13Z" yahoo:lang="en-US">
    <diagnostics>
        <publiclyCallable>true</publiclyCallable>
        <url execution-time="2" proxy="DEFAULT"><![CDATA[http://datatables.org/alltables.env]]></url>
        <url execution-time="2" proxy="DEFAULT"><![CDATA[http://www.datatables.org/yahoo/finance/yahoo.finance.quotes.xml]]></url>
        <url execution-time="9" proxy="DEFAULT"><![CDATA[http://download.finance.yahoo.com/d/quotes.csv?f=aa2bb2b3b4cc1c3c6c8dd1d2ee1e7e8e9ghjkg1g3g4g5g6ii5j1j3j4j5j6k1k2k4k5ll1l2l3mm2m3m4m5m6m7m8nn4opp1p2p5p6qrr1r2r5r6r7ss1s7t1t7t8vv1v7ww1w4xy&s=BP]]></url>
        <url execution-time="11"><![CDATA[select * from csv where url=@url and columns='Ask,AverageDailyVolume,Bid,AskRealtime,BidRealtime,BookValue,Change&PercentChange,Change,Commission,ChangeRealtime,AfterHoursChangeRealtime,DividendShare,LastTradeDate,TradeDate,EarningsShare,ErrorIndicationreturnedforsymbolchangedinvalid,EPSEstimateCurrentYear,EPSEstimateNextYear,EPSEstimateNextQuarter,DaysLow,DaysHigh,YearLow,YearHigh,HoldingsGainPercent,AnnualizedGain,HoldingsGain,HoldingsGainPercentRealtime,HoldingsGainRealtime,MoreInfo,OrderBookRealtime,MarketCapitalization,MarketCapRealtime,EBITDA,ChangeFromYearLow,PercentChangeFromYearLow,LastTradeRealtimeWithTime,ChangePercentRealtime,ChangeFromYearHigh,PercebtChangeFromYearHigh,LastTradeWithTime,LastTradePriceOnly,HighLimit,LowLimit,DaysRange,DaysRangeRealtime,FiftydayMovingAverage,TwoHundreddayMovingAverage,ChangeFromTwoHundreddayMovingAverage,PercentChangeFromTwoHundreddayMovingAverage,ChangeFromFiftydayMovingAverage,PercentChangeFromFiftydayMovingAverage,Name,Notes,Open,PreviousClose,PricePaid,ChangeinPercent,PriceSales,PriceBook,ExDividendDate,PERatio,DividendPayDate,PERatioRealtime,PEGRatio,PriceEPSEstimateCurrentYear,PriceEPSEstimateNextYear,Symbol,SharesOwned,ShortRatio,LastTradeTime,TickerTrend,OneyrTargetPrice,Volume,HoldingsValue,HoldingsValueRealtime,YearRange,DaysValueChange,DaysValueChangeRealtime,StockExchange,DividendYield']]></url>
        <javascript execution-time="26" instructions-used="67513" table-name="yahoo.finance.quotes"/>
        <user-time>48</user-time>
        <service-time>13</service-time>
        <build-version>9128</build-version>
    </diagnostics> 
    <results>
        <quote symbol="BP">
            <Ask/>
            <AverageDailyVolume>38597700</AverageDailyVolume>
            <Bid/>
            <AskRealtime>38.25</AskRealtime>
            <BidRealtime>38.15</BidRealtime>
            <BookValue>27.294</BookValue>
            <Change_PercentChange>-0.34 - -0.88%</Change_PercentChange>
            <Change>-0.34</Change>
            <Commission/>
            <ChangeRealtime>-0.34</ChangeRealtime>
            <AfterHoursChangeRealtime>N/A - N/A</AfterHoursChangeRealtime>
            <DividendShare>2.52</DividendShare>
            <LastTradeDate>9/15/2010</LastTradeDate>
            <TradeDate/>
            <EarningsShare>-0.462</EarningsShare>
            <ErrorIndicationreturnedforsymbolchangedinvalid>N/A</ErrorIndicationreturnedforsymbolchangedinvalid>
            <EPSEstimateCurrentYear>6.14</EPSEstimateCurrentYear>
            <EPSEstimateNextYear>6.38</EPSEstimateNextYear>
            <EPSEstimateNextQuarter>1.38</EPSEstimateNextQuarter>
            <DaysLow>37.77</DaysLow>
            <DaysHigh>38.25</DaysHigh>
            <YearLow>26.75</YearLow>
            <YearHigh>62.38</YearHigh>
            <HoldingsGainPercent>- - -</HoldingsGainPercent>
            <AnnualizedGain>-</AnnualizedGain>
            <HoldingsGain/>
            <HoldingsGainPercentRealtime>N/A - N/A</HoldingsGainPercentRealtime>
            <HoldingsGainRealtime/>
            <MoreInfo>cnprmIed</MoreInfo>
            <OrderBookRealtime>N/A</OrderBookRealtime>
            <MarketCapitalization>119.6B</MarketCapitalization>
            <MarketCapRealtime/>
            <EBITDA>7.272B</EBITDA>
            <ChangeFromYearLow>+11.43</ChangeFromYearLow>
            <PercentChangeFromYearLow>+42.73%</PercentChangeFromYearLow>
            <LastTradeRealtimeWithTime>N/A - &lt;b&gt;38.18&lt;/b&gt;</LastTradeRealtimeWithTime>
            <ChangePercentRealtime>N/A - -0.88%</ChangePercentRealtime>
            <ChangeFromYearHigh>-24.20</ChangeFromYearHigh>
            <PercebtChangeFromYearHigh>-38.79%</PercebtChangeFromYearHigh>
            <LastTradeWithTime>Sep 15 - &lt;b&gt;38.18&lt;/b&gt;</LastTradeWithTime>
            <LastTradePriceOnly>38.18</LastTradePriceOnly>
            <HighLimit/>
            <LowLimit/>
            <DaysRange>37.77 - 38.25</DaysRange>
            <DaysRangeRealtime>N/A - N/A</DaysRangeRealtime>
            <FiftydayMovingAverage>37.8139</FiftydayMovingAverage>
            <TwoHundreddayMovingAverage>44.0511</TwoHundreddayMovingAverage>
            <ChangeFromTwoHundreddayMovingAverage>-5.8711</ChangeFromTwoHundreddayMovingAverage>
            <PercentChangeFromTwoHundreddayMovingAverage>-13.33%</PercentChangeFromTwoHundreddayMovingAverage>
            <ChangeFromFiftydayMovingAverage>+0.3661</ChangeFromFiftydayMovingAverage>
            <PercentChangeFromFiftydayMovingAverage>+0.97%</PercentChangeFromFiftydayMovingAverage>
            <Name>BP p.l.c. Common</Name>
            <Notes>-</Notes>
            <Open>38.08</Open>
            <PreviousClose>38.52</PreviousClose>
            <PricePaid/>
            <ChangeinPercent>-0.88%</ChangeinPercent>
            <PriceSales>0.42</PriceSales>
            <PriceBook>1.41</PriceBook>
            <ExDividendDate>May  5</ExDividendDate>
            <PERatio/>
            <DividendPayDate>Jun 21</DividendPayDate>
            <PERatioRealtime/>
            <PEGRatio>1.25</PEGRatio>
            <PriceEPSEstimateCurrentYear>6.27</PriceEPSEstimateCurrentYear>
            <PriceEPSEstimateNextYear>6.04</PriceEPSEstimateNextYear>
            <Symbol>BP</Symbol>
            <SharesOwned/>
            <ShortRatio>0.80</ShortRatio>
            <LastTradeTime>4:00pm</LastTradeTime>
            <TickerTrend>&amp;nbsp;+-+=+-&amp;nbsp;</TickerTrend>
            <OneyrTargetPrice>47.27</OneyrTargetPrice>
            <Volume>6831680</Volume>
            <HoldingsValue/>
            <HoldingsValueRealtime/>
            <YearRange>26.75 - 62.38</YearRange>
            <DaysValueChange>- - -0.88%</DaysValueChange>
            <DaysValueChangeRealtime>N/A - N/A</DaysValueChangeRealtime>
            <StockExchange>NYSE</StockExchange>
            <DividendYield>6.54</DividendYield>
            <PercentChange>-0.88%</PercentChange>
        </quote>
    </results>
</query>

Answer 1

I don’t think Yahoo provides a Java API. You’ll have to create an XML schema, then use an XML library to create entity classes (JAXB or similar). It’s also possible to get YQL data in JSON, in that case I’d use the Google GSON parser and create the entity class manually.