Comments.java Source code

Introduction

Here is the source code for Comments.java

Source

//package org.zkoss.maven.yuicompressor.util;

public class Comments {
    //
    //   public static String readFile(String file) {
    //      try {
    //         Scanner scanner = new Scanner(new FileReader(new File(file)));
    //         StringBuffer sb = new StringBuffer();
    //         while (scanner.hasNextLine()) {
    //            sb.append(scanner.nextLine()+"\r\n");
    //            
    //         }
    //         return sb.toString();
    //      } catch (Exception e) {
    //         return "";
    //      }
    //   }
    //
    //   public static void main(String[] args) {
    //
    //      System.out.println(removeComment(readFile("skin.js")));
    //      
    //   }

    public static String removeComment(String input) {

        StringBuffer sb = new StringBuffer(input);
        char NQ = ' ', quote = NQ;
        int len = sb.length();
        for (int j = 0, lineno = 1; j < len; j++) {
            if (sb.charAt(j) == '\n')
                ++lineno;

            if (quote != NQ) {
                if (sb.charAt(j) == quote) {
                    quote = NQ;
                } else if (sb.charAt(j) == '\\') {
                    j++;
                    //fix for  "123\\\r\n123" 
                    if (sb.charAt(j) == '\r')
                        j++;
                    // if(sb.charAt(j) == '\n') j++;
                } else if (sb.charAt(j) == '\n') {
                    throw new IllegalStateException("Unterminated string at line " + lineno);
                }
            } else if (sb.charAt(j) == '/' && j + 1 < len && (sb.charAt(j + 1) == '*' || sb.charAt(j + 1) == '/')) {
                int l = j;
                boolean eol = sb.charAt(++j) == '/';
                while (++j < len) {
                    if (sb.charAt(j) == '\n')
                        ++lineno;

                    if (eol) {
                        if (sb.charAt(j) == '\n') {
                            sb.delete(l, sb.charAt(j - 1) == '\r' ? j - 1 : j);
                            len = sb.length();
                            j = l;
                            break;
                        }
                    } else if (sb.charAt(j) == '*' && j + 1 < len && sb.charAt(j + 1) == '/') {
                        sb.delete(l, j + 2);
                        len = sb.length();
                        j = l;
                        break;
                    }
                }
            } else if (sb.charAt(j) == '\'' || sb.charAt(j) == '"') {
                quote = sb.charAt(j);
            } else if (sb.charAt(j) == '/') { // regex
                boolean regex = false;
                for (int k = j;;) {
                    if (--k < 0) {
                        regex = true;
                        break;
                    }

                    char ck = sb.charAt(k);
                    if (!Character.isWhitespace(ck)) {
                        regex = ck == '(' || ck == ',' || ck == '=' || ck == ':' || ck == '?' || ck == '{'
                                || ck == '[' || ck == ';' || ck == '!' || ck == '&' || ck == '|' || ck == '^'
                                || (ck == 'n' && k > 4 && "return".equals(sb.substring(k - 5, k + 1)))
                                || (ck == 'e' && k > 2 && "case".equals(sb.substring(k - 3, k + 1)));
                        break;
                    }
                }
                if (regex) {
                    while (++j < len && sb.charAt(j) != '/') {
                        if (sb.charAt(j) == '\\')
                            j++;
                        else if (sb.charAt(j) == '\n') {
                            throw new IllegalStateException("Unterminated regex at line " + lineno);
                        }
                    }
                }
            }
        }
        return sb.toString();
    }

}