使用jaxb将xml字符串转换为java对象

Question

I am getting an 832edi file with namespaces as xml string, i need to extract elements from this xml string. So i have generated jaxb classes based on 832edi file. When i am trying to store the contents of the xml string i am getting the following exception

javax.xml.bind.JAXBElement cannot be cast to org.bam.jaxb.Transaction834

I am using the following code to parse the xml string

JAXBContext jaxbContext = JAXBContext.newInstance("org.bam.jaxb");
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
StringReader reader = new StringReader(im.getPayload());
Transaction834 edi = (Transaction834) unmarshaller.unmarshal(reader);
List<Loop2000> loop2000=edi.getLoop2000();
System.out.println(loop2000.get(10));

where im.getPayload() will return an xml string . Here is the fragment of the xml.

<?xml version = '1.0' encoding = 'UTF-8'?><Transaction-834 xmlns:zcha="http://www.edifecs.com/xdata/200" XDataVersion="2.0" Standard="X12" Version="V5010" GUID="{C7846049-8C91-4E59-B0BA-4B24CEE69FBB}" CreatedBy="XEngine_4016" CreatedDate="2013-09-05T12:36:12" xmlns="http://www.edifecs.com/xdata/200"><zcha:Segment-ISA><zcha:Element-I01 Offset="4" Size="2">00</zcha:Element-I01><zcha:Element-I02 Offset="7" Size="10">Authorizat</zcha:Element-I02><zcha:Element-I03 Offset="18" Size="2">00</zcha:Element-I03><zcha:Element-I04 Offset="21" Size="10">Security I</zcha:Element-I04><zcha:Element-I05 Offset="32" Size="2">01</zcha:Element-I05><zcha:Element-I06 Offset="35" Size="15">Interchange Sen</zcha:Element-I06><zcha:Element-I05_1 Offset="51" Size="2">01</zcha:Element-I05_1><zcha:Element-I07 Offset="54" Size="15">Interchange Rec</zcha:Element-I07><zcha:Element-I08 Offset="70" Size="6">130905</zcha:Element-I08><zcha:Element-I09 Offset="77" Size="4">1236</zcha:Element-I09><zcha:Element-I65 Offset="82" Size="1">*</zcha:Element-I65><zcha:Element-I11 Offset="84" Size="5">00501</zcha:Element-I11><zcha:Element-I12 Offset="90" Size="9">000000001</zcha:Element-I12><zcha:Element-I13 Offset="100" Size="1">0</zcha:Element-I13><zcha:Element-I14 Offset="102" Size="1">I</zcha:Element-I14><zcha:Element-I15 Offset="104" Size="1">\</zcha:Element-I15></zcha:Segment-ISA><zcha:Segment-GS><zcha:Element-479 Offset="110" Size="2">BE</zcha:Element-479><zcha:Element-142 Offset="113" Size="15">Application Sen</zcha:Element-142><zcha:Element-124 Offset="129" Size="15">Application Rec</zcha:Element-124><zcha:Element-373 Offset="145" Size="8">20130905</zcha:Element-373><zcha:Element-337 Offset="154" Size="6">123602</zcha:Element-337><zcha:Element-28 Offset="161" Size="1">1</zcha:Element-28><zcha:Element-455 Offset="163" Size="1">T</zcha:Element-455><zcha:Element-480 Offset="165" Size="6">005010</zcha:Element-480></zcha:Segment-GS><zcha:Segment-ST><zcha:Element-143 Offset="176" Size="3">834</zcha:Element-143><zcha:Element-329 Offset="180" Size="4">0001</zcha:Element-329></zcha:Segment-ST><zcha:Segment-BGN><zcha:Element-353 Offset="190" Size="2">00</zcha:Element-353><zcha:Element-127 Offset="193" Size="24">Reference Identification</zcha:Element-127><zcha:Element-373 Offset="218" Size="8">20130905</zcha:Element-373></zcha:Segment-BGN><zcha:Loop-1000><zcha:Segment-N1><zcha:Element-98 Offset="231" Size="2">00</zcha:Element-98><zcha:Element-93 Offset="234" Size="4">Name</zcha:Element-93></zcha:Segment-N1><zcha:Segment-N4/></zcha:Loop-1000><zcha:Segment-SE><zcha:Element-96 Offset="243" Size="1">4</zcha:Element-96><zcha:Element-329 Offset="245" Size="4">0001</zcha:Element-329></zcha:Segment-SE><zcha:Segment-GE><zcha:Element-97 Offset="254" Size="1">1</zcha:Element-97><zcha:Element-28 Offset="256" Size="1">1</zcha:Element-28></zcha:Segment-GE><zcha:Segment-IEA><zcha:Element-I16 Offset="263" Size="1">1</zcha:Element-I16><zcha:Element-I12 Offset="265" Size="9">000000001</zcha:Element-I12></zcha:Segment-IEA></Transaction-834>

Here Transaction834 is the root element of the xsd.Please could you suggest me where am i doing the mistake ? thanks for your patience.

Answer 1

Most likely the class Transaction834 doesn't specify the XmlRootElement annotation (probably because it's a top-level type rather than an anonymous type).

In this case you have to use something like:

JAXBElement<Transaction834> ediElement = unmarshaller.unmarshal(new StreamSource(reader), Transaction834.class);
Transaction834 edi = ediElement.getValue();

Answer 2

When you aren't sure whether the result returned from JAXB will be you can use JAXBInstropector to do any unwrapping of the JAXBElement if necessary.

JAXBContext jaxbContext = JAXBContext.newInstance("org.bam.jaxb");
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
StringReader reader = new StringReader(im.getPayload());
Transaction834 edi = (Transaction834) JAXBIntrospector.getValue(unmarshaller.unmarshal(reader));

For More Information

• http://blog.bdoughan.com/2012/07/jaxb-and-root-elements.html