TextDiffHelper.java example

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test4j-master
package org.test4j.tools.commons;

import java.io.FileNotFoundException;
import java.util.LinkedList;

import org.test4j.tools.commons.TextDiffMatchPatch.Diff;
import org.test4j.tools.commons.TextDiffMatchPatch.Operation;

import ext.test4j.apache.commons.lang.StringEscapeUtils;

public class TextDiffHelper {
    private static String     style    = "";
    static {
        StringBuffer buff = new StringBuffer();
        buff.append("<style type=\"text/css\" media=\"all\">\n");
        try {
            String css = ResourceHelper.readFromFile("org/test4j/utility/text-diff.css");
            buff.append(css);
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        }
        buff.append("</style>\n");
        style = buff.toString();
    }
    static TextDiffMatchPatch textDiff = new TextDiffMatchPatch();

    /**
     * 比较左边文件内容和右边文件内容的区别，并且返回比较差异内容的html
     * 
     * @param lText
     * @param rText
     * @return
     */
    public static String getDiffHtml(String lText, String rText) {
        LinkedList<Diff> diffs = textDiff.diff_main(lText, rText);
        String compare = textDiff.diff_prettyHtml(diffs);

        StringBuilder buff = new StringBuilder();
        buff.append("<html>\n");
        buff.append("<head>\n");
        buff.append(style);
        buff.append("</head>\n");
        buff.append("<body>\n");

        buff.append("<div id=\"topPanel\">\n");
        String diffSize = getDiffSize(diffs);
        buff.append(diffSize);
        printDiffText(buff, compare);
        buff.append("</div>\n");
        buff.append("<div id=\"vSplitter\"></div>\n");
        buff.append("<div>\n");
        buff.append("<div id=\"leftPanel\" class=\"buttom buttomPanel\">\n");
        printHtmlText(buff, lText);
        buff.append("</div>\n");
        buff.append("<div id=\"hSplitter\" class=\"buttom\"></div>\n");
        buff.append("<div id=\"rightPanel\" class=\"buttom buttomPanel\">\n");
        printHtmlText(buff, rText);
        buff.append("</div>\n");
        buff.append("</div>\n");
        buff.append("</body>\n");
        buff.append("</html>");
        return buff.toString();
    }

    /**
     * 比较左边和右边的文件，返回比较差异
     * 
     * @param lText
     * @param rText
     * @return
     */
    public static LinkedList<Diff> getDiff(String lText, String rText) {
        LinkedList<Diff> diffs = textDiff.diff_main(lText, rText);
        return diffs;
    }

    static String getDiffSize(LinkedList<Diff> diffs) {
        int count = 0;
        for (Diff diff : diffs) {
            if (diff.operation == Operation.EQUAL) {
                continue;
            }
            count++;
        }
        if (count == 0) {
            return "<p>No Difference.</p>";
        } else if (count == 1) {
            return "<p>" + diffs.size() + " difference.</p>";
        } else {
            return "<p>" + diffs.size() + " differences.</p>";
        }
    }

    static void printDiffText(StringBuilder buff, String text) {
        text = text.replace("¶", "").replace("    ", "    ");
        ;
        buff.append(text);
    }

    static void printHtmlText(StringBuilder buff, String text) {
        text = text.replace("\n", "!@#$BR$#@!");
        text = text.replace(" ", "!@#$SP$#@!");
        text = StringEscapeUtils.escapeXml(text);
        text = text.replace("!@#$SP$#@!", " ");
        text = text.replace("!@#$BR$#@!", "<BR/>");
        buff.append(text);
    }
}