使用 StAX 读取 XML 字符串

问题描述

我第一次使用 stax 来解析 XML 字符串.我找到了一些示例，但无法使我的代码正常工作.这是我的代码的最新版本:

I am using stax for the first time to parse an XML String. I have found some examples but can't get my code to work. This is the latest version of my code:

public class AddressResponseParser
{
    private static final String STATUS = "status";
    private static final String ADDRESS_ID = "address_id";
    private static final String CIVIC_ADDRESS = "civic_address";

    String status = null;
    String addressId = null;
    String civicAddress = null;

    public static AddressResponse parseAddressResponse(String response)
    {

        try
        {
            byte[] byteArray = response.getBytes("UTF-8");
            ByteArrayInputStream inputStream = new ByteArrayInputStream(byteArray);
            XMLInputFactory inputFactory = XMLInputFactory.newInstance();
            XMLStreamReader reader = inputFactory.createXMLStreamReader(inputStream);

            while (reader.hasNext())
            {
                int event = reader.next();

                if (event == XMLStreamConstants.START_ELEMENT)
                {
                    String element = reader.getLocalName();

                    if (element.equals(STATUS))
                    {
                        status = reader.getElementText();
                        continue;
                    }

                    if (element.equals(ADDRESS_ID))
                    {
                        addressId = reader.getText();
                        continue;
                    }

                    if (element.equals(CIVIC_ADDRESS))
                    {
                        civicAddress = reader.getText();
                        continue;
                    }
                }
            }
        }
        catch (Exception e)
        {
            log.error("Couldn't parse AddressResponse", e);
        }
    }
}

我已经对event"和reader.getElementText()"进行了监视.当代码停止时

I've put watches on "event" and "reader.getElementText()". When the code is stopped on

String element = reader.getLocalName();

会显示reader.getElementText()"值，但一旦它离开该行，就无法对其进行评估.当代码停止时:

the "reader.getElementText()" value is displayed, but as soon as it moves away from that line it can't be evaluated. When the code is stopped on:

status = reader.getElementText();

元素"手表显示正确的值.最后，当我再执行代码一行时，我发现了这个异常:

the "element" watch displays the correct value. Finally, when I step the code one more line, I catch this exception:

(com.ctc.wstx.exc.WstxParsingException) com.ctc.wstx.exc.WstxParsingException: Current state not START_ELEMENT
 at [row,col {unknown-source}]: [1,29]

我尝试使用 status = reader.getText(); 代替，但后来我得到了这个异常:

I've tried using status = reader.getText(); instead, but then I get this exception:

(java.lang.IllegalStateException) java.lang.IllegalStateException: Not a textual event (END_ELEMENT)

谁能指出我做错了什么??

Can somebody point out what I'm doing wrong??

添加用于测试的 JUnit 代码:

Adding JUnit code used to test:

public class AddressResponseParserTest
{
    private String status = "OK";
    private String address_id = "123456";
    private String civic_address = "727";

    @Test
    public void testAddressResponseParser() throws UnsupportedEncodingException, XMLStreamException
    {
        AddressResponse parsedResponse = AddressResponseParser.parseAddressResponse(this.responseXML());

        assertEquals(this.status, parsedResponse.getStatus());

        assertEquals(this.address_id, parsedResponse.getAddress()
                .getAddressId());
        assertEquals(this.civic_address, parsedResponse.getAddress()
                .getCivicAddress());
    }

    private String responseXML()
    {
        StringBuffer buffer = new StringBuffer();

        buffer.append("<response>");
        buffer.append("<status>OK</status>");
        buffer.append("<address>");
        buffer.append("<address_id>123456</address_id>");
        buffer.append("<civic_address>727</civic_address>");
        buffer.append("</address>");
        buffer.append("</response>");

        return buffer.toString();
    }
}

推荐答案

我找到了一个使用 XMLEventReader 代替 XMLStreamReader 的解决方案:

I found a solution that uses XMLEventReader instead of XMLStreamReader:

public MyObject parseXML(String xml)
    throws XMLStreamException, UnsupportedEncodingException
{
    byte[] byteArray = xml.getBytes("UTF-8");
    ByteArrayInputStream inputStream = new ByteArrayInputStream(byteArray);
    XMLInputFactory inputFactory = XMLInputFactory.newInstance();
    XMLEventReader reader = inputFactory.createXMLEventReader(inputStream);

    MyObject object = new MyObject();

    while (reader.hasNext())
    {
        XMLEvent event = (XMLEvent) reader.next();

        if (event.isStartElement())
        {
            StartElement element = event.asStartElement();

            if (element.getName().getLocalPart().equals("ElementOne"))
            {
                event = (XMLEvent) reader.next();

                if (event.isCharacters())
                {
                     String elementOne = event.asCharacters().getData();
                     object.setElementOne(elementOne);
                }
                continue;
            }
            if (element.getName().getLocalPart().equals("ElementTwo"))
            {
                event = (XMLEvent) reader.next();
                if (event.isCharacters())
                {
                     String elementTwo = event.asCharacters().getData();
                     object.setElementTwo(elementTwo);
                }
                continue;
            }
        }
    }

    return object;
}

我仍然有兴趣看到使用 XMLStreamReader 的解决方案.

I would still be interested in seeing a solution using XMLStreamReader.

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