XPathBuilder.java 文件源码

/**
 * Creates a new xpath expression as there we no available in the pool.
 * <p/>
 * This implementation must be synchronized to ensure thread safety, as this XPathBuilder instance may not have been
 * started prior to being used.
 */
protected synchronized XPathExpression createXPathExpression() throws XPathExpressionException, XPathFactoryConfigurationException {
    // ensure we are started
    try {
        start();
    } catch (Exception e) {
        throw new RuntimeExpressionException("Error starting XPathBuilder", e);
    }

    // XPathFactory is not thread safe
    XPath xPath = getXPathFactory().newXPath();

    if (!logNamespaces && LOG.isTraceEnabled()) {
        LOG.trace("Creating new XPath expression in pool. Namespaces on XPath expression: {}", getNamespaceContext().toString());
    } else if (logNamespaces && LOG.isInfoEnabled()) {
        LOG.info("Creating new XPath expression in pool. Namespaces on XPath expression: {}", getNamespaceContext().toString());
    }
    xPath.setNamespaceContext(getNamespaceContext());
    xPath.setXPathVariableResolver(getVariableResolver());

    XPathFunctionResolver parentResolver = getFunctionResolver();
    if (parentResolver == null) {
        parentResolver = xPath.getXPathFunctionResolver();
    }
    xPath.setXPathFunctionResolver(createDefaultFunctionResolver(parentResolver));
    return xPath.compile(text);
}