import com.sun.org.apache.xml.internal.serializer.utils.DOM2Helper; //导入依赖的package包/类
/**
 * Constructor.
 * @param   contentHandler The implemention of the
 * contentHandler operation (toXMLString, digest, ...)
 */
public TreeWalker(ContentHandler contentHandler, String systemId)
{
    // Set the content handler
    m_contentHandler = contentHandler;
    if (m_contentHandler instanceof SerializationHandler) {
        m_Serializer = (SerializationHandler) m_contentHandler;
    } else {
        m_Serializer = null;
    }
    // Set the system ID, if it is given
    m_contentHandler.setDocumentLocator(m_locator);
    if (systemId != null) {
        m_locator.setSystemId(systemId);
    }

    m_dh = new DOM2Helper();
}
 

import com.sun.org.apache.xml.internal.serializer.utils.DOM2Helper; //导入依赖的package包/类
/**
 * Constructor.
 * @param   contentHandler The implemention of the
 * contentHandler operation (toXMLString, digest, ...)
 */
public TreeWalker(ContentHandler contentHandler, String systemId)
{
    // Set the content handler
    m_contentHandler = contentHandler;
    if (m_contentHandler instanceof SerializationHandler) {
        m_Serializer = (SerializationHandler) m_contentHandler;
    } else {
        m_Serializer = null;
    }

    // Set the system ID, if it is given
    m_contentHandler.setDocumentLocator(m_locator);
    if (systemId != null) {
        m_locator.setSystemId(systemId);
    }

    m_dh = new DOM2Helper();
}