import com.sun.org.apache.xml.internal.serializer.ToXMLStream; //导入依赖的package包/类
/**
 * Constructor:  Creates a LSSerializerImpl object.  The underlying
 * XML 1.0 or XML 1.1 org.apache.xml.serializer.Serializer object is
 * created and initialized the first time any of the write methods are
 * invoked to serialize the Node.  Subsequent write methods on the same
 * LSSerializerImpl object will use the previously created Serializer object.
 */
public LSSerializerImpl () {
    // set default parameters
    fFeatures |= CDATA;
    fFeatures |= COMMENTS;
    fFeatures |= ELEM_CONTENT_WHITESPACE;
    fFeatures |= ENTITIES;
    fFeatures |= NAMESPACES;
    fFeatures |= NAMESPACEDECLS;
    fFeatures |= SPLITCDATA;
    fFeatures |= WELLFORMED;
    fFeatures |= DISCARDDEFAULT;
    fFeatures |= XMLDECL;

    // New OutputFormat properties
    fDOMConfigProperties = new Properties();

    // Initialize properties to be passed on the underlying serializer
    initializeSerializerProps();

    // Read output_xml.properties and System Properties to initialize properties
    Properties  configProps = OutputPropertiesFactory.getDefaultMethodProperties("xml");

    // change xml version from 1.0 to 1.1
    //configProps.setProperty("version", "1.1");

    // Get a serializer that seriailizes according to the properties,
    // which in this case is to xml
    fXMLSerializer = new ToXMLStream();
    fXMLSerializer.setOutputFormat(configProps);

    // Initialize Serializer
    fXMLSerializer.setOutputFormat(fDOMConfigProperties);
}