Java XML Node Tree dump(final Node node)

Description

Recursively walks the DOM tree starting at the given Node printing the gory details of its construction to System.out.

License

Open Source License

Parameter

Parameter	Description
node	The <CODE>Node</CODE> to start the dump at.

Declaration

public static void dump(final Node node) 

Method Source Code

//package com.java2s;
// This software is licensed in accordance with the terms of the 'Open Source

import java.io.PrintStream;
import java.io.PrintWriter;

import org.w3c.dom.Attr;
import org.w3c.dom.CDATASection;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.Text;

public class Main {
    /**/*from  w  ww.j a  va 2s .c  o m*/
     * Recursively walks the DOM tree starting at the given <CODE>Node</CODE>
     * printing the gory details of its construction to <CODE>System.out</CODE>.
     * 
     * @param    node         The <CODE>Node</CODE> to start the dump at.
     * @since   TFP 1.0
     */
    public static void dump(final Node node) {
        doDump(System.out, node, 0);
    }

    /**
     * Recursively walks the DOM tree starting at the given <CODE>Node</CODE>
     * printing the gory details of its construction to the indicated
     * <CODE>PrintStream</CODE>.
     * 
     * @param   out            The <CODE>PrintStream</CODE> for output.
     * @param    node         The <CODE>Node</CODE> to start the dump at.
     * @since   TFP 1.0
     */
    public static void dump(PrintStream out, final Node node) {
        doDump(out, node, 0);
        out.flush();
    }

    /**
     * Recursively walks the DOM tree starting at the given <CODE>Node</CODE>
     * printing the gory details of its construction to the indicated
     * <CODE>PrintWriter</CODE>.
     * 
     * @param   out            The <CODE>PrintWriter</CODE> for output.
     * @param    node         The <CODE>Node</CODE> to start the dump at.
     * @since   TFP 1.0
     */
    public static void dump(PrintWriter out, final Node node) {
        doDump(out, node, 0);
        out.flush();
    }

    /**
     * Performs the actual recursive dumping of a DOM tree to a given
     * <CODE>PrintStream</CODE>. Note that dump is intended to be a detailed
     * debugging aid rather than pretty to look at. 
     * 
     * @param    out            The <CODE>PrintStream</CODE> to write to.
     * @param    node         The <CODE>Node</CODE> under consideration.
     * @param    indent         The level of indentation.
     * @see      #dump(Node)
     * @see      #dump(PrintStream, Node)
     * @since   TFP 1.0
     */
    private static void doDump(PrintStream out, final Node node, int indent) {
        if (node != null) {
            for (int index = 0; index < indent; ++index)
                out.write(' ');

            switch (node.getNodeType()) {
            case Node.DOCUMENT_NODE: {
                Document document = (Document) node;

                out.println("DOCUMENT:");

                doDump(out, document.getDoctype(), indent + 1);
                doDump(out, document.getDocumentElement(), indent + 1);
                break;
            }

            case Node.DOCUMENT_TYPE_NODE: {
                DocumentType type = (DocumentType) node;

                out.println("DOCTYPE: [" + "name=" + format(type.getName()) + "," + "publicId="
                        + format(type.getPublicId()) + "," + "systemId=" + format(type.getSystemId()) + "]");
                break;
            }

            case Node.ELEMENT_NODE: {
                Element element = (Element) node;

                out.println("ELEMENT: [" + "ns=" + format(element.getNamespaceURI()) + "," + "name="
                        + format(element.getLocalName()) + "]");

                NamedNodeMap attrs = element.getAttributes();

                for (int index = 0; index < attrs.getLength(); ++index)
                    doDump(out, attrs.item(index), indent + 1);

                for (Node child = element.getFirstChild(); child != null;) {
                    doDump(out, child, indent + 1);
                    child = child.getNextSibling();
                }
                break;
            }
            case Node.ATTRIBUTE_NODE: {
                Attr attr = (Attr) node;

                out.println("ATTRIBUTE: [" + "ns=" + format(attr.getNamespaceURI()) + "," + "prefix="
                        + format(attr.getPrefix()) + "," + "name=" + format(attr.getLocalName()) + "," + "value="
                        + format(attr.getNodeValue()) + "]");
                break;
            }

            case Node.TEXT_NODE: {
                Text text = (Text) node;

                out.println("TEXT: [" + format(text.getNodeValue()) + "]");

                for (Node child = text.getFirstChild(); child != null;) {
                    doDump(out, child, indent + 1);
                    child = child.getNextSibling();
                }
                break;
            }

            case Node.CDATA_SECTION_NODE: {
                CDATASection data = (CDATASection) node;

                out.println("CDATA: [" + format(data.getNodeValue()) + "]");
                break;
            }

            case Node.COMMENT_NODE: {
                Comment comm = (Comment) node;

                out.println("COMMENT: [" + format(comm.getNodeValue()) + "]");
                break;
            }

            default:
                out.println("UNKNOWN: [type=" + node.getNodeType() + "]");
                break;
            }
        }
    }

    /**
     * Performs the actual recursive dumping of a DOM tree to a given
     * <CODE>PrintWriter</CODE>. Note that dump is intended to be a detailed
     * debugging aid rather than pretty to look at. 
     * 
     * @param    out            The <CODE>PrintWriter</CODE> to write to.
     * @param    node         The <CODE>Node</CODE> under consideration.
     * @param    indent         The level of indentation.
     * @see      #dump(PrintWriter, Node)
     * @since   TFP 1.0
     */
    private static void doDump(PrintWriter out, final Node node, int indent) {
        if (node != null) {
            for (int index = 0; index < indent; ++index)
                out.write(' ');

            switch (node.getNodeType()) {
            case Node.DOCUMENT_NODE: {
                Document document = (Document) node;

                out.println("DOCUMENT:");

                doDump(out, document.getDoctype(), indent + 1);
                doDump(out, document.getDocumentElement(), indent + 1);
                break;
            }

            case Node.DOCUMENT_TYPE_NODE: {
                DocumentType type = (DocumentType) node;

                out.println("DOCTYPE: [" + "name=" + format(type.getName()) + "," + "publicId="
                        + format(type.getPublicId()) + "," + "systemId=" + format(type.getSystemId()) + "]");
                break;
            }

            case Node.ELEMENT_NODE: {
                Element element = (Element) node;

                out.println("ELEMENT: [" + "ns=" + format(element.getNamespaceURI()) + "," + "name="
                        + format(element.getLocalName()) + "]");

                NamedNodeMap attrs = element.getAttributes();

                for (int index = 0; index < attrs.getLength(); ++index)
                    doDump(out, attrs.item(index), indent + 1);

                for (Node child = element.getFirstChild(); child != null;) {
                    doDump(out, child, indent + 1);
                    child = child.getNextSibling();
                }
                break;
            }
            case Node.ATTRIBUTE_NODE: {
                Attr attr = (Attr) node;

                out.println("ATTRIBUTE: [" + "ns=" + format(attr.getNamespaceURI()) + "," + "prefix="
                        + format(attr.getPrefix()) + "," + "name=" + format(attr.getLocalName()) + "," + "value="
                        + format(attr.getNodeValue()) + "]");
                break;
            }

            case Node.TEXT_NODE: {
                Text text = (Text) node;

                out.println("TEXT: [" + format(text.getNodeValue()) + "]");

                for (Node child = text.getFirstChild(); child != null;) {
                    doDump(out, child, indent + 1);
                    child = child.getNextSibling();
                }
                break;
            }

            case Node.CDATA_SECTION_NODE: {
                CDATASection data = (CDATASection) node;

                out.println("CDATA: [" + format(data.getNodeValue()) + "]");
                break;
            }

            case Node.COMMENT_NODE: {
                Comment comm = (Comment) node;

                out.println("COMMENT: [" + format(comm.getNodeValue()) + "]");
                break;
            }

            default:
                out.println("UNKNOWN: [type=" + node.getNodeType() + "]");
                break;
            }
        }
    }

    /**
     * Converts a <CODE>String</CODE> value to a displayable format for
     * debugging. This entails wrapping non-null strings with quotes and
     * replacing null strings with the word 'null'.
     * 
     * @param    value         The <CODE>String</CODE> to be formatted.
     * @return   The formatted <CODE>String</CODE> value.
     * @since   TFP 1.0
     */
    private static String format(final String value) {
        if (value != null)
            return ("\"" + value + "\"");
        else
            return ("null");
    }
}

Related

1. dump(Node node)
2. dumpTree(Node node)
3. moveSubTree(Node from, Node to, Node context)