org.saiku.adhoc.utils.XmlUtils.java Source code

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Here is the source code for org.saiku.adhoc.utils.XmlUtils.java

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/*
 * Copyright (C) 2011 Marius Giepz
 *
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU General Public License as published by the Free 
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * 
 * See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along 
 * with this program; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 *
 */

package org.saiku.adhoc.utils;

import java.io.StringWriter;

import org.dom4j.DocumentHelper;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

/**
 * XML utils, including formatting.
 */
public class XmlUtils {

    private static final int LINE_LENGTH = 80;
    private static final int INTENTATION = 2;

    private static XmlFormatter formatter = new XmlFormatter(INTENTATION, LINE_LENGTH);

    private static class XmlFormatter {
        private int indentNumChars;
        private int lineLength;
        private boolean singleLine;

        public XmlFormatter(int indentNumChars, int lineLength) {
            this.indentNumChars = indentNumChars;
            this.lineLength = lineLength;
        }

        public synchronized String format(String s, int initialIndent) {
            int indent = initialIndent;
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < s.length(); i++) {
                char currentChar = s.charAt(i);
                if (currentChar == '<') {
                    char nextChar = s.charAt(i + 1);
                    if (nextChar == '/')
                        indent -= indentNumChars;
                    if (!singleLine) // Don't indent before closing element if we're creating opening and closing elements on a single line.
                        sb.append(buildWhitespace(indent));
                    if (nextChar != '?' && nextChar != '!' && nextChar != '/')
                        indent += indentNumChars;
                    singleLine = false; // Reset flag.
                }
                sb.append(currentChar);
                if (currentChar == '>') {
                    if (s.charAt(i - 1) == '/') {
                        indent -= indentNumChars;
                        sb.append("\n");
                    } else {
                        int nextStartElementPos = s.indexOf('<', i);
                        if (nextStartElementPos > i + 1) {
                            String textBetweenElements = s.substring(i + 1, nextStartElementPos);

                            // If the space between elements is solely newlines, let them through to preserve additional newlines in source document.
                            if (textBetweenElements.replaceAll("\n", "").length() == 0) {
                                sb.append(textBetweenElements + "\n");
                            }
                            // Put tags and text on a single line if the text is short.
                            //              else if (textBetweenElements.length() <= lineLength * 0.5)
                            //              {
                            sb.append(textBetweenElements);
                            //                singleLine = true;
                            //              }
                            //              // For larger amounts of text, wrap lines to a maximum line length.
                            //              else
                            //              {
                            //              //  sb.append("\n" + lineWrap(textBetweenElements, lineLength, indent, null) + "\n");
                            //              }
                            i = nextStartElementPos - 1;
                        } else {
                            sb.append("\n");
                        }
                    }
                }
            }
            return sb.toString();
        }
    }

    private static String buildWhitespace(int numChars) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < numChars; i++)
            sb.append(" ");
        return sb.toString();
    }

    /**
     * Wraps the supplied text to the specified line length.
     * @lineLength the maximum length of each line in the returned string (not including indent if specified).
     * @indent optional number of whitespace characters to prepend to each line before the text.
     * @linePrefix optional string to append to the indent (before the text).
     * @returns the supplied text wrapped so that no line exceeds the specified line length + indent, optionally with
     * indent and prefix applied to each line.
     */
    private static String lineWrap(String s, int lineLength, Integer indent, String linePrefix) {
        if (s == null)
            return null;

        StringBuilder sb = new StringBuilder();
        int lineStartPos = 0;
        int lineEndPos;
        boolean firstLine = true;
        while (lineStartPos < s.length()) {
            if (!firstLine)
                sb.append("\n");
            else
                firstLine = false;

            if (lineStartPos + lineLength > s.length())
                lineEndPos = s.length() - 1;
            else {
                lineEndPos = lineStartPos + lineLength - 1;
                while (lineEndPos > lineStartPos && (s.charAt(lineEndPos) != ' ' && s.charAt(lineEndPos) != '\t'))
                    lineEndPos--;
            }
            sb.append(buildWhitespace(indent));
            if (linePrefix != null)
                sb.append(linePrefix);

            sb.append(s.substring(lineStartPos, lineEndPos + 1));
            lineStartPos = lineEndPos + 1;
        }
        return sb.toString();
    }

    public static String prettyPrint(final String xml) {
        StringWriter sw = null;

        try {
            final OutputFormat format = new OutputFormat("  ", true);
            //OutputFormat.createPrettyPrint();
            final org.dom4j.Document document = DocumentHelper.parseText(xml);
            sw = new StringWriter();
            final XMLWriter writer = new XMLWriter(sw, format);
            writer.write(document);
        } catch (Exception e) {
            System.out.println("creating beautified xml failed, refer to exc : " + e.getMessage());
        }
        return sw.toString();
    }

}