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How to parse XML using SAX?

I get an XML document from a REST service that is processed using SAX. See the following example that was created from XSD.

Setting up the parser is not a problem. My main problem is the actual processing in methods startElement(), endElement()etc. I don’t understand how to extract the elements I need and store them, because they are somewhat “nested”.

Example

ConnectionListcan occur once or twice and may contain any number of elements Connection, which, in turn, have information about the connection. Basically, I need a list of all the connections from them Date, Transfersand Time. Should I create one class for each element?

As I understand it, I somehow need to do the following: If the parser comes across ...

  • ConnectionList: create a new object ConnectionListand put it in ConnectionLists list
  • Connection: create a new Connection object and put it in the connection list
  • Date, Transfers, Time(Only if the parent Duration): Save the value of the node in the current objectConnection

I would really appreciate any help, hint, idea, fragment, how I can achieve this.

Thank: -)

Robert

<?xml version="1.0" encoding="UTF-8"?>
<ResC xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <Err code="r5E5a1Wm" text="tk-gWYbw" level="E"/>
    <Err code="takVDd34" text="XtvyjmjPuscK" level="E"/>
    <Err code="hQ1-:aDQ" text="YWc5qtY.gkwCeJW2S" level="E"/>
    <ConRes dir="R">
        <Err code="ZfwPC:tj" text="RKKFuLXoM0oOfp3a" level="E"/>
        <Err code="bhDjSJPa" text="BJoHuOMdwzhcddW" level="E"/>
        <Err code="CX-NhK9r" text="j55qy-WiNPXu" level="E"/>
        <ConResCtxt b="1" f="1">0815</ConResCtxt>
        <ConnectionList type="IV">
            <Err code="WI3WX.jo" text="rK3H5jwa-Zfen3" level="E"/>
            <Connection id="ID000">
                <Overview>
                    <Date>b3lcM_Yiyq7dqL9</Date>
                    <Departure>
                        <BasicStop type="NORMAL" index="-1086549314">
                            <Address externalId="t.EdKe93xkqFqLwPzgd-4vHSJemy8"
                                externalStationNr="1332105793" name="fdREYJPu83WV503V8szdCX"
                                x="951177990" y="-1579782776" z="1807457957" type="WGS84"/>
                        </BasicStop>
                    </Departure>
                    <Arrival>
                        <BasicStop type="NORMAL" index="1897526979">
                            <Address externalId="l7h_GTUit6fv" externalStationNr="-1670310329"
                                name="WJznDTzkTvyET51pfr7X" x="-1738098662" y="-170353174"
                                z="-475585957" type="WGS84"/>
                        </BasicStop>
                    </Arrival>
                    <Transfers>dZbgZfDH8j1hb1i</Transfers>
                    <Duration>
                        <Time>00d00:18:00</Time>
                    </Duration>
                    <ServiceDays> </ServiceDays>
                    <Products>
                        <Product cat="qmrN2dShHJp"/>
                        <Product cat="Hg"/>
                        <Product cat="nurxhdl3w.P0x7FRv2J3UoF"/>
                    </Products>
                    <ContextURL url="http://FzgEqiVC/"/>
                </Overview>
            </Connection>
            <Connection id="ID004">
                <Overview>
                    <Date>W5a47DRkc7XDZjhwq_s5Un.</Date>
                    <Departure>
                        <BasicStop type="NORMAL" index="-1014429844">
                            <Address externalId="RMnzjEFOTTdM1oaAUw" externalStationNr="1429101638"
                                name="HF-1" x="1005198487" y="570832676" z="975615566" type="WGS84"
                            />
                        </BasicStop>
                    </Departure>
                    <Arrival>
                        <BasicStop type="NORMAL" index="-58308182">
                            <Address externalId="rVdwdQvAukfj2QcA7b3OSdGOyW"
                                externalStationNr="1142334006" name="g" x="-1791416159"
                                y="-541300941" z="478129823" type="WGS84"/>
                        </BasicStop>
                    </Arrival>
                    <Transfers>GG56XN6zgiJF804mE_N4o</Transfers>
                    <Duration> </Duration>
                    <ServiceDays> </ServiceDays>
                    <Products>
                        <Product cat="fs_Oyoy9NYBai-qaxbty6j9Y7r1St"/>
                        <Product cat="P2CbaSGpC"/>
                        <Product cat="CGZrqSIDM6M4kUlb8_xZ8jRlH4c"/>
                    </Products>
                    <ContextURL url="http://JkRhuXtu/"/>
                </Overview>
            </Connection>
        </ConnectionList>
        <ConnectionList type="IV">
            <Err code="0lFWRY2X" text="KLmdczFRhV" level="E"/>
            <Connection id="ID012">
                <Overview>
                    <Date>t8mn634zjCZsRPyxj_e_-UYMH</Date>
                    <Departure>
                        <BasicStop type="NORMAL" index="-2095085423">
                            <Address externalId="ftKAFG-Uk7x" externalStationNr="1390920810"
                                name="JQrQXOQbm.FLaCMeSiTYjT" x="1970142849" y="-655980297"
                                z="2102464970" type="WGS84"/>
                        </BasicStop>
                    </Departure>
                    <Arrival>
                        <BasicStop type="NORMAL" index="1552118247">
                            <Address externalId="qcBpeuPDRzvSt1o" externalStationNr="-1133118359"
                                name="AJiJOB1t" x="-1422533132" y="-1158953133" z="484831466"
                                type="WGS84"/>
                        </BasicStop>
                    </Arrival>
                    <Transfers>D0MiUwW9nuuM_uykvawg2C07pwHL</Transfers>
                    <Duration> </Duration>
                    <ServiceDays> </ServiceDays>
                    <Products>
                        <Product cat="LpGOZbLDbJm"/>
                        <Product cat="JIv-szQVX2icPb"/>
                        <Product cat="Q7-pthWoOT"/>
                    </Products>
                    <ContextURL url="http://zGWgivvi/"/>
                </Overview>
                <IList>
                    <I header="ze4Wt3hVD-DvjujY6QKae" text="lVwB4RxAHcYq3.F"
                        uriCustom="iVjQJCoU1MVOv2Z9lwarP"/>
                    <I header="z-i.au59soMzXLZCbV" text="PoTP" uriCustom="ksrbwEH6scNR"/>
                    <I header="N" text="jHDA4" uriCustom="ub95811lMIa_495ZbPOuNWL0rRWh"/>
                </IList>
                <CommentList>
                    <Comment id="ID013">
                        <Text lang="EN"> </Text>
                        <Text lang="FR"> </Text>
                        <Text lang="PL"> </Text>
                    </Comment>
                    <Comment id="ID014">
                        <Text lang="DK"> </Text>
                        <Text lang="IT"> </Text>
                        <Text lang="IT"> </Text>
                    </Comment>
                    <Comment id="ID015">
                        <Text lang="MACRO"> </Text>
                        <Text lang="IT"> </Text>
                        <Text lang="EN"> </Text>
                    </Comment>
                </CommentList>
            </Connection>
        </ConnectionList>
    </ConRes>
</ResC>
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6 answers

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Your program should keep track of where you are in the document. If you analyze "on the fly", a simple stack structure will be created - you push the name onto the stack when you get the "entry level" and you push the stack to "endelement".

If you find that you are building a tree structure, I would switch to a DOM parser, because everything you write will be a pale and bad shadow of something like XERCES.

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