Java tutorial
//package org.zkoss.maven.yuicompressor; import java.io.IOException; import java.io.Reader; import java.io.Writer; import java.util.regex.Matcher; import java.util.regex.Pattern; /* * YUI Compressor * Author: Julien Lecomte <jlecomte@yahoo-inc.com> * Copyright (c) 2007, Yahoo! Inc. All rights reserved. * Code licensed under the BSD License: * http://developer.yahoo.net/yui/license.txt * * This code is a port of Isaac Schlueter's cssmin utility. * *---- * This code is a port of com.yahoo.platform.yui.compressor.CssCompressor * we modify the version for zk css.dsp compress. (To avoid that $ make error happen.); */ public class CssCompressor { private StringBuffer srcsb = new StringBuffer(); public CssCompressor(Reader in) throws IOException { // Read the stream... int c; while ((c = in.read()) != -1) { srcsb.append((char) c); } } public String getSrc() { return srcsb.toString(); } public void compress(Writer out, int linebreakpos) throws IOException { Pattern p; Matcher m; String css; StringBuffer sb; int startIndex, endIndex; // Remove all comment blocks... startIndex = 0; boolean iemac = false; boolean preserve = false; sb = new StringBuffer(srcsb.toString()); while ((startIndex = sb.indexOf("/*", startIndex)) >= 0) { preserve = sb.length() > startIndex + 2 && sb.charAt(startIndex + 2) == '!'; endIndex = sb.indexOf("*/", startIndex + 2); if (endIndex < 0) { if (!preserve) { sb.delete(startIndex, sb.length()); } } else if (endIndex >= startIndex + 2) { if (sb.charAt(endIndex - 1) == '\\') { // Looks like a comment to hide rules from IE Mac. // Leave this comment, and the following one, alone... startIndex = endIndex + 2; iemac = true; } else if (iemac) { startIndex = endIndex + 2; iemac = false; } else if (!preserve) { sb.delete(startIndex, endIndex + 2); } else { startIndex = endIndex + 2; } } } css = sb.toString(); // Normalize all whitespace strings to single spaces. Easier to work // with that way. css = css.replaceAll("\\s+", " "); // Make a pseudo class for the Box Model Hack css = css.replaceAll("\"\\\\\"}\\\\\"\"", "___PSEUDOCLASSBMH___"); // ---------where zk modify it sb = new StringBuffer(); p = Pattern.compile("\\$\\{([^\\}]+)\\}"); Matcher m1 = p.matcher(css); while (m1.find()) { String s1 = m1.group(); s1 = s1.replaceAll("\\$\\{", "__EL__"); s1 = s1.replaceAll(":", "__ELSP__"); s1 = s1.replaceAll("\\}", "__ELEND__"); m1.appendReplacement(sb, s1); } m1.appendTail(sb); css = sb.toString(); // ---------where zk modify it----end // Remove the spaces before the things that should not have spaces // before them. // But, be careful not to turn "p :link {...}" into "p:link{...}" // Swap out any pseudo-class colons with the token, and then swap back. sb = new StringBuffer(); p = Pattern.compile("(^|\\})(([^\\{:])+:)+([^\\{]*\\{)"); m = p.matcher(css); while (m.find()) { String s = m.group(); s = s.replaceAll(":", "___PSEUDOCLASSCOLON___"); m.appendReplacement(sb, s); } m.appendTail(sb); css = sb.toString(); css = css.replaceAll("\\s+([!{};:>+\\(\\)\\],])", "$1"); css = css.replaceAll("___PSEUDOCLASSCOLON___", ":"); // Remove the spaces after the things that should not have spaces after // them. css = css.replaceAll("([!{}:;>+\\(\\[,])\\s+", "$1"); // Add the semicolon where it's missing. css = css.replaceAll("([^;\\}])}", "$1;}"); // Replace 0(px,em,%) with 0. css = css.replaceAll("([\\s:])(0)(px|em|%|in|cm|mm|pc|pt|ex)", "$1$2"); // Replace 0 0 0 0; with 0. css = css.replaceAll(":0 0 0 0;", ":0;"); css = css.replaceAll(":0 0 0;", ":0;"); css = css.replaceAll(":0 0;", ":0;"); // Replace background-position:0; with background-position:0 0; css = css.replaceAll("background-position:0;", "background-position:0 0;"); // Replace 0.6 to .6, but only when preceded by : or a white-space css = css.replaceAll("(:|\\s)0+\\.(\\d+)", "$1.$2"); // Shorten colors from rgb(51,102,153) to #336699 // This makes it more likely that it'll get further compressed in the // next step. p = Pattern.compile("rgb\\s*\\(\\s*([0-9,\\s]+)\\s*\\)"); m = p.matcher(css); sb = new StringBuffer(); while (m.find()) { String[] rgbcolors = m.group(1).split(","); StringBuffer hexcolor = new StringBuffer("#"); for (int i = 0; i < rgbcolors.length; i++) { int val = Integer.parseInt(rgbcolors[i]); if (val < 16) { hexcolor.append("0"); } hexcolor.append(Integer.toHexString(val)); } m.appendReplacement(sb, hexcolor.toString()); } m.appendTail(sb); css = sb.toString(); // Shorten colors from #AABBCC to #ABC. Note that we want to make sure // the color is not preceded by either ", " or =. Indeed, the property // filter: chroma(color="#FFFFFF"); // would become // filter: chroma(color="#FFF"); // which makes the filter break in IE. p = Pattern.compile( "([^\"'=\\s])(\\s*)#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])"); m = p.matcher(css); sb = new StringBuffer(); while (m.find()) { // Test for AABBCC pattern if (m.group(3).equalsIgnoreCase(m.group(4)) && m.group(5).equalsIgnoreCase(m.group(6)) && m.group(7).equalsIgnoreCase(m.group(8))) { m.appendReplacement(sb, m.group(1) + m.group(2) + "#" + m.group(3) + m.group(5) + m.group(7)); } else { m.appendReplacement(sb, m.group()); } } m.appendTail(sb); css = sb.toString(); // Remove empty rules. css = css.replaceAll("[^\\}]+\\{;\\}", ""); if (linebreakpos >= 0) { // Some source control tools don't like it when files containing // lines longer // than, say 8000 characters, are checked in. The linebreak option // is used in // that case to split long lines after a specific column. int i = 0; int linestartpos = 0; sb = new StringBuffer(css); while (i < sb.length()) { char c = sb.charAt(i++); if (c == '}' && i - linestartpos > linebreakpos) { sb.insert(i, '\n'); linestartpos = i; } } css = sb.toString(); } // Replace the pseudo class for the Box Model Hack css = css.replaceAll("___PSEUDOCLASSBMH___", "\"\\\\\"}\\\\\"\""); // Replace multiple semi-colons in a row by a single one // See SF bug #1980989 css = css.replaceAll(";;+", ";"); // ---------where zk modify it css = css.replaceAll("__EL__", "\\$\\{"); css = css.replaceAll("__ELSP__", ":"); css = css.replaceAll("__ELEND__", "\\}"); // ---------where zk modify it----end // Trim the final string (for any leading or trailing white spaces) css = css.trim(); // Write the output... out.write(css); } }