replaceregexp.java

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    /**
     * A substitution pattern.  You can use this element to refer to a previously
     * defined substitution pattern datatype instance.
     * @return the substitution pattern object to be configured as an element
     */
    public Substitution createSubstitution() {
        if (subs != null) {
            throw new BuildException("Only one substitution expression is "
                                     + "allowed");
        }

        subs = new Substitution();
        return subs;
    }


    /**
     * Invoke a regular expression (r) on a string (input) using
     * substitutions (s) for a matching regex.
     *
     * @param r a regular expression
     * @param s a Substitution
     * @param input the string to do the replacement on
     * @param options The options for the regular expression
     * @return the replacement result
     */
    protected String doReplace(RegularExpression r,
                               Substitution s,
                               String input,
                               int options) {
        String res = input;
        Regexp regexp = r.getRegexp(getProject());

        if (regexp.matches(input, options)) {
            log("Found match; substituting", Project.MSG_DEBUG);
            res = regexp.substitute(input, s.getExpression(getProject()),
                                    options);
        }

        return res;
    }


    /**
     *  Perform the replacement on a file
     *
     * @param f the file to perform the relacement on
     * @param options the regular expressions options
     * @exception IOException if an error occurs
     */
    protected void doReplace(File f, int options)
         throws IOException {
        File temp = FILE_UTILS.createTempFile("replace", ".txt", null, true, true);

        Reader r = null;
        Writer w = null;

        try {
            if (encoding == null) {
                r = new FileReader(f);
                w = new FileWriter(temp);
            } else {
                r = new InputStreamReader(new FileInputStream(f), encoding);
                w = new OutputStreamWriter(new FileOutputStream(temp),
                                           encoding);
            }

            BufferedReader br = new BufferedReader(r);
            BufferedWriter bw = new BufferedWriter(w);
            PrintWriter pw = new PrintWriter(bw);

            boolean changes = false;

            log("Replacing pattern '" + regex.getPattern(getProject())
                + "' with '" + subs.getExpression(getProject())
                + "' in '" + f.getPath() + "'" + (byline ? " by line" : "")
                + (flags.length() > 0 ? " with flags: '" + flags + "'" : "")
                + ".", Project.MSG_VERBOSE);

            if (byline) {
                StringBuffer linebuf = new StringBuffer();
                String line = null;
                String res = null;
                int c;
                boolean hasCR = false;

                do {
                    c = br.read();

                    if (c == '\r') {
                        if (hasCR) {
                            // second CR -> EOL + possibly empty line
                            line = linebuf.toString();
                            res  = doReplace(regex, subs, line, options);

                            if (!res.equals(line)) {
                                changes = true;
                            }

                            pw.print(res);
                            pw.print('\r');

                            linebuf = new StringBuffer();
                            // hasCR is still true (for the second one)
                        } else {
                            // first CR in this line
                            hasCR = true;
                        }
                    } else if (c == '\n') {
                        // LF -> EOL
                        line = linebuf.toString();
                        res  = doReplace(regex, subs, line, options);

                        if (!res.equals(line)) {
                            changes = true;
                        }

                        pw.print(res);
                        if (hasCR) {
                            pw.print('\r');
                            hasCR = false;
                        }
                        pw.print('\n');

                        linebuf = new StringBuffer();
                    } else { // any other char
                        if ((hasCR) || (c < 0)) {
                            // Mac-style linebreak or EOF (or both)
                            line = linebuf.toString();
                            res  = doReplace(regex, subs, line, options);

                            if (!res.equals(line)) {
                                changes = true;
                            }

                            pw.print(res);
                            if (hasCR) {
                                pw.print('\r');
                                hasCR = false;
                            }

                            linebuf = new StringBuffer();
                        }

                        if (c >= 0) {
                            linebuf.append((char) c);
                        }
                    }
                } while (c >= 0);

                pw.flush();
            } else {
                String buf = FileUtils.safeReadFully(br);

                String res = doReplace(regex, subs, buf, options);

                if (!res.equals(buf)) {
                    changes = true;
                }

                pw.print(res);
                pw.flush();
            }

            r.close();
            r = null;
            w.close();
            w = null;

            if (changes) {
                log("File has changed; saving the updated file", Project.MSG_VERBOSE);
                try {
                    FILE_UTILS.rename(temp, f);
                    temp = null;
                } catch (IOException e) {
                    throw new BuildException("Couldn't rename temporary file "
                                             + temp, getLocation());
                }
            } else {
                log("No change made", Project.MSG_DEBUG);
            }
        } finally {
            FileUtils.close(r);
            FileUtils.close(w);
            if (temp != null) {
                temp.delete();
            }
        }
    }


    /**
     * Execute the task
     *
     * @throws BuildException is there is a problem in the task execution.
     */
    public void execute() throws BuildException {
        if (regex == null) {
            throw new BuildException("No expression to match.");
        }
        if (subs == null) {
            throw new BuildException("Nothing to replace expression with.");
        }

        if (file != null && filesets.size() > 0) {
            throw new BuildException("You cannot supply the 'file' attribute "
                                     + "and filesets at the same time.");
        }

        int options = 0;

        if (flags.indexOf('g') != -1) {
            options |= Regexp.REPLACE_ALL;
        }

        if (flags.indexOf('i') != -1) {
            options |= Regexp.MATCH_CASE_INSENSITIVE;
        }

        if (flags.indexOf('m') != -1) {
            options |= Regexp.MATCH_MULTILINE;
        }

        if (flags.indexOf('s') != -1) {
            options |= Regexp.MATCH_SINGLELINE;
        }

        if (file != null && file.exists()) {
            try {
                doReplace(file, options);
            } catch (IOException e) {
                log("An error occurred processing file: '"
                    + file.getAbsolutePath() + "': " + e.toString(),
                    Project.MSG_ERR);
            }
        } else if (file != null) {
            log("The following file is missing: '"
                + file.getAbsolutePath() + "'", Project.MSG_ERR);
        }

        int sz = filesets.size();

        for (int i = 0; i < sz; i++) {
            FileSet fs = (FileSet) (filesets.elementAt(i));
            DirectoryScanner ds = fs.getDirectoryScanner(getProject());

            String[] files = ds.getIncludedFiles();

            for (int j = 0; j < files.length; j++) {
                File f = new File(fs.getDir(getProject()), files[j]);

                if (f.exists()) {
                    try {
                        doReplace(f, options);
                    } catch (Exception e) {
                        log("An error occurred processing file: '"
                            + f.getAbsolutePath() + "': " + e.toString(),
                            Project.MSG_ERR);
                    }
                } else {
                    log("The following file is missing: '"
                        + f.getAbsolutePath() + "'", Project.MSG_ERR);
                }
            }
        }
    }

}