BIRT：无法检索 XML 数据源。 XML 数据源文件无效或该文件不存在

我创建了一个 XML 数据源，用于从本地应用程序获取 XML 数据。创建数据集时出现以下错误。

org.eclipse.datatools.connectivity.oda.OdaException: XML data source cannot be retrieved. XML data source file is invalid or the file doesn't exist.
    at org.eclipse.datatools.enablement.oda.xml.ui.wizards.XPathChoosePage.populateXMLTree(XPathChoosePage.java:482)
    at org.eclipse.datatools.enablement.oda.xml.ui.wizards.XPathChoosePage.createPageCustomControl(XPathChoosePage.java:121)
    at org.eclipse.datatools.connectivity.oda.design.ui.wizards.DataSetWizardPage.createControl(DataSetWizardPage.java:123)
    at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:174)
    at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:736)
    at org.eclipse.jface.wizard.WizardDialog.setWizard(WizardDialog.java:1182)
    at org.eclipse.jface.wizard.WizardDialog.updateForPage(WizardDialog.java:1241)
    at org.eclipse.jface.wizard.WizardDialog.access$4(WizardDialog.java:1238)
    at org.eclipse.jface.wizard.WizardDialog$8.run(WizardDialog.java:1227)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.jface.wizard.WizardDialog.showPage(WizardDialog.java:1225)
    at org.eclipse.jface.wizard.WizardDialog.nextPressed(WizardDialog.java:915)
    at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:428)

XML URL 返回以下数据：

<table>
  <row>
    <marketName>dd</marketName>
    <commodityName>Black Barley</commodityName>
    <priceType>Wholesale</priceType>
    <pricePerQtl>58.0</pricePerQtl>
    <date>2014-07-03 15:18:21</date>
  </row>
</table>

我只能在一种情况下重现这一点，即开始标记之前有空格。因此请确保没有空格。

<?xml version="1.0" encoding="UTF-8"?>
<table>
  <row>
    <marketName>dd</marketName>
    <commodityName>Black Barley</commodityName>
    <priceType>Wholesale</priceType>
    <pricePerQtl>58.0</pricePerQtl>
    <date>2014-07-03 15:18:21</date>
  </row>
</table>