Question

我正在使用STAX事件API来读取从SOAP调用接收的二进制数据，并希望将其传递给使用者。 SOAP调用的XML有效负载如下所示：

    .........
    <BinaryObject mimeCode="text/xml">PHNvYXAtZW52OkVudmVsb3BlIHhtbG5zOnNvYXAtZW52PSJodHRwOi8vc
         2NoZW1hcy54bWxzb2FwLhm9yZy9zb2FwL2VudmVsb3BlLyI+DQogICA8c29hcC1lbnY6SGVhZGVy
         Lz4NCiAgIDxzb2FwLWVudjpCb2R5Pg0KICAgICAgPG5tOkF0dGFjaG1lbnRGb2xkZXJEb2N1bWVudE
         ZpbGVDb250ZW50QnlJRFJlc3BvbnNlX3N5bmMgeG1sbnM6bm09Imh0dHA6Ly9zYXAuY29tL3hpL1NB
         UEdsb2JhbDIwL0dsb2JhbCIgeG1sbnM6cHJ4PSJ1cm46c2FwLmNvbTpwcm94eTpISlc6LzFTQUkvVE
         FTMEIzNDE4MTJBNTc5MDUyM0I5RTU6ODA0Ij4NCiAgICAgICAgIDxBdHRhY..... </BinaryObject>

以下用于解析数据并将数据发送给消费者的java代码

    XMLInputFactory inputFactory = XMLInputFactory.newInstance();
    inputFactory.setProperty(XMLInputFactory.IS_COALESCING, true);

    InputStream in;

    try {

        in = new ByteArrayInputStream(response.getBytes());

        XMLEventReader eventReader;
        eventReader = inputFactory.createXMLEventReader(in);

        while (eventReader.hasNext()) {
            XMLEvent event = eventReader.nextEvent();

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

                if (startElement.getName().getLocalPart().toString()
                        .equals("BinaryObject")) {

                    Iterator<Attribute> attributes = startElement
                            .getAttributes();

                    while (attributes.hasNext()) {
                        Attribute attribute = attributes.next();

                        if (attribute.getName().toString()
                                .equals("mimeCode")) {
                            mimeType = attribute.getValue();
                        }
                    }

                    event = eventReader.peek();

                    if (event.isCharacters()) {
                        event = eventReader.nextEvent();
                        content = event.asCharacters().getData();
                    }
                }
            }
        }

    } catch (XMLStreamException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    m_servletResponse.setContentType(mimeType);
        m_servletResponse.getWriter().print(javax.xml.bind.DatatypeConverter
                .printBase64Binary(content.getBytes()));

此代码存在多个问题：

对于较大的文件（＆gt; 1 MB），我收到了StackOverflow错误
当我尝试使用png文件时，即使对于较小的文件，我也会收到文件无效的错误（在消费者处）。

我如何克服这些问题？

PS：我第一次使用STAX !!

的的 ==================== 编辑： ==================== **

根据以下Evgeniy的建议，我现在能够处理小文件（例如PNG）。然而，对于大型说PDF文档＆gt; 1 MB我收到以下错误。关于这里出了什么问题的任何想法？

2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null #exce in thread“http -bio-8041-exec-9“| 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous #http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃java.lang.StackOverflowError | 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃at com.sun.org.apache .xerces.internal.impl.XMLScanner.isInvalid（XMLScanner.java:1334）| 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃at com.sun.org.apache .xerces.internal.impl.XMLScanner.scanCharReferenceValue（XMLScanner.java:1294）| 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃at com.sun.org.apache .xerces.internal.impl.XMLDocumentFragmentScannerImpl $ FragmentContentDriver.next（XMLDocumentFragmentScannerImpl.java:3024）| 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃at com.sun.org.apache .xerces.internal.impl.XMLDocumentFragmentScannerImpl $ FragmentContentDriver.next（XMLDocumentFragmentScannerImpl.java:2919）| 2012 12 09 06:50:19＃+ 00＃ERROR＃System.err ## anonymous＃http-bio-8041-exec-9 ## seodportal＃seodportal #web #null #null＃at com.sun.org.apache .xerces.internal.impl.XMLDocumentFragmentScannerImpl $ FragmentContentDriver.next（XMLDocumentFragmentScannerImpl.java:3059）|

Answer 1

首先，XMLStreamReader是为特殊目的而设计的，而是使用XMLStreamReader。这是一个工作示例

        XMLInputFactory inputFactory = XMLInputFactory.newInstance();
        inputFactory.setProperty(XMLInputFactory.IS_COALESCING, true);
        InputStream in = new ByteArrayInputStream(response.getBytes());
        XMLStreamReader xr = inputFactory.createXMLStreamReader(in);
        while (xr.hasNext()) {
            int next = xr.next();
            if (next == XMLStreamConstants.START_ELEMENT) {
                if (xr.getLocalName().equals("BinaryObject")) {
                    String mimeCode = xr.getAttributeValue(null, "mimeCode");
                    if (mimeCode.equals("text/xml")) {
                        xr.next();
                    // for efficiency we can access xr inner buffer chars directly
                    char[] b = xr.getTextCharacters();
                    int textStart = xr.getTextStart();
                    int textLength = xr.getTextLength();
                    // or simply get it as String  
                    String text = xr.getText();
                    // in this example I will use JDK's internal decoder com.sun.org.apache.xerces.internal.impl.dv.util.Base64                     
                    byte[] bytes = new Base64().decode(text);

                    }
                }
            }
        }

STAX API读取二进制数据

1 个答案: