清华大佬耗费三个月吐血整理的几百G的资源，免费分享！....>>>
通过移除空行和注释来压缩 JavaScript 代码
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 | /** * This file is part of the Echo Web Application Framework (hereinafter \"Echo\"). * Copyright (C) 2002-2009 NextApp, Inc. * * Compresses a String containing JavaScript by removing comments and whitespace. */public class JavaScriptCompressor { private static final char LINE_FEED = \'\\n\'; private static final char CARRIAGE_RETURN = \'\\r\'; private static final char SPACE = \' \'; private static final char TAB = \'\\t\'; /** * Compresses a String containing JavaScript by removing comments and * whitespace. * * @param script the String to compress * @return a compressed version */ public static String compress(String script) { JavaScriptCompressor jsc = new JavaScriptCompressor(script); return jsc.outputBuffer.toString(); } /** Original JavaScript text. */ private String script; /** * Compressed output buffer. * This buffer may only be modified by invoking the <code>append()</code> * method. */ private StringBuffer outputBuffer; /** Current parser cursor position in original text. */ private int pos; /** Character at parser cursor position. */ private char ch; /** Last character appended to buffer. */ private char lastAppend; /** Flag indicating if end-of-buffer has been reached. */ private boolean endReached; /** Flag indicating whether content has been appended after last identifier. */ private boolean contentAppendedAfterLastIdentifier = true; /** * Creates a new <code>JavaScriptCompressor</code> instance. * * @param script */ private JavaScriptCompressor(String script) { this.script = script; outputBuffer = new StringBuffer(script.length()); nextChar(); while (!endReached) { if (Character.isJavaIdentifierStart(ch)) { renderIdentifier(); } else if (ch == \' \') { skipWhiteSpace(); } else if (isWhitespace()) { // Compress whitespace skipWhiteSpace(); } else if ((ch == \'\"\') || (ch == \'\\\'\')) { // Handle strings renderString(); } else if (ch == \'/\') { // Handle comments nextChar(); if (ch == \'/\') { nextChar(); skipLineComment(); } else if (ch == \'*\') { nextChar(); skipBlockComment(); } else { append(\'/\'); } } else { append(ch); nextChar(); } } } /** * Append character to output. * * @param ch the character to append */ private void append(char ch) { lastAppend = ch; outputBuffer.append(ch); contentAppendedAfterLastIdentifier = true; } /** * Determines if current character is whitespace. * * @return true if the character is whitespace */ private boolean isWhitespace() { return ch == CARRIAGE_RETURN || ch == SPACE || ch == TAB || ch == LINE_FEED; } /** * Load next character. */ private void nextChar() { if (!endReached) { if (pos < script.length()) { ch = script.charAt(pos++); } else { endReached = true; ch = 0; } } } /** * Adds an identifier to output. */ private void renderIdentifier() { if (!contentAppendedAfterLastIdentifier) append(SPACE); append(ch); nextChar(); while (Character.isJavaIdentifierPart(ch)) { append(ch); nextChar(); } contentAppendedAfterLastIdentifier = false; } /** * Adds quoted String starting at current character to output. */ private void renderString() { char startCh = ch; // Save quote char append(ch); nextChar(); while (true) { if ((ch == LINE_FEED) || (ch == CARRIAGE_RETURN) || (endReached)) { // JavaScript error: string not terminated return; } else { if (ch == \'\\\\\') { append(ch); nextChar(); if ((ch == LINE_FEED) || (ch == CARRIAGE_RETURN) || (endReached)) { // JavaScript error: string not terminated return; } append(ch); nextChar(); } else { append(ch); if (ch == startCh) { nextChar(); return; } nextChar(); } } } } /** * Moves cursor past a line comment. */ private void skipLineComment() { while ((ch != CARRIAGE_RETURN) && (ch != LINE_FEED)) { if (endReached) { return; } nextChar(); } } /** * Moves cursor past a block comment. */ private void skipBlockComment() { while (true) { if (endReached) { return; } if (ch == \'*\') { nextChar(); if (ch == \'/\') { nextChar(); return; } } else nextChar(); } } /** * Renders a new line character, provided previously rendered character * is not a newline. */ private void renderNewLine() { if (lastAppend != \'\\n\' && lastAppend != \'\\r\') { append(\'\\n\'); } } /** * Moves cursor past white space (including newlines). */ private void skipWhiteSpace() { if (ch == LINE_FEED || ch == CARRIAGE_RETURN) { renderNewLine(); } else { append(ch); } nextChar(); while (ch == LINE_FEED || ch == CARRIAGE_RETURN || ch == SPACE || ch == TAB) { if (ch == LINE_FEED || ch == CARRIAGE_RETURN) { renderNewLine(); } nextChar(); } }} |