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* @param byline the byline attribute as a string * @deprecated since 1.6.x. * Use setByLine(boolean). */ public void setByLine(String byline) { Boolean res = Boolean.valueOf(byline); if (res == null) { res = Boolean.FALSE; } this.byline = res.booleanValue(); } /** * Process the file(s) one line at a time, executing the replacement * on one line at a time. This is useful if you * want to only replace the first occurrence of a regular expression on * each line, which is not easy to do when processing the file as a whole. * Defaults to <i>false. * @param byline the byline attribute */ public void setByLine(boolean byline) { this.byline = byline; } /** * Specifies the encoding Ant expects the files to be in - * defaults to the platforms default encoding. * @param encoding the encoding attribute * * @since Ant 1.6 */ public void setEncoding(String encoding) { this.encoding = encoding; } /** * list files to apply the replacement to * @param set the fileset element */ public void addFileset(FileSet set) { filesets.addElement(set); } /** * A regular expression. * You can use this element to refer to a previously * defined regular expression datatype instance * @return the regular expression object to be configured as an element */ public RegularExpression createRegexp() { if (regex != null) { throw new BuildException("Only one regular expression is allowed."); } regex = new RegularExpression(); return regex; } /** * 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); temp.deleteOnExit(); 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.readFully(br); if (buf == null) { buf = ""; } 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); } } } } }

Other Ant examples (source code examples)

Here is a short list of links related to this Ant ReplaceRegExp.java source code file:

Ant example source code file (ReplaceRegExp.java)

This example Ant source code file (ReplaceRegExp.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Ant tags/keywords

buildexception, buildexception, file, fileset, io, ioexception, only, regularexpression, string, string, stringbuffer, stringbuffer, substitution, substitution, util, vector

The ReplaceRegExp.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant.taskdefs.optional;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DirectoryScanner;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.FileSet;
import org.apache.tools.ant.types.RegularExpression;
import org.apache.tools.ant.types.Substitution;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.util.regexp.Regexp;

/**
 * Performs regular expression string replacements in a text
 * file.  The input file(s) must be able to be properly processed by
 * a Reader instance.  That is, they must be text only, no binary.
 *
 * The syntax of the regular expression depends on the implementation that
 * you choose to use. The system property <code>ant.regexp.regexpimpl
 * will be the classname of the implementation that will be used (the default
 * is <code>org.apache.tools.ant.util.regexp.JakartaOroRegexp and
 * requires the Jakarta Oro Package).
 *
 * <pre>
 * For jdk  <= 1.3, there are two available implementations:
 *   org.apache.tools.ant.util.regexp.JakartaOroRegexp (the default)
 *        Requires  the jakarta-oro package
 *
 *   org.apache.tools.ant.util.regexp.JakartaRegexpRegexp
 *        Requires the jakarta-regexp package
 *
 * For jdk >= 1.4 an additional implementation is available:
 *   org.apache.tools.ant.util.regexp.Jdk14RegexpRegexp
 *        Requires the jdk 1.4 built in regular expression package.
 *
 * Usage:
 *
 *   Call Syntax:
 *
 *     <replaceregexp file="file"
 *                    match="pattern"
 *                    replace="pattern"
 *                    flags="options"?
 *                    byline="true|false"? >
 *       regexp?
 *       substitution?
 *       fileset*
 *     </replaceregexp>
 *
 *    NOTE: You must have either the file attribute specified, or at least one fileset subelement
 *    to operation on.  You may not have the file attribute specified if you nest fileset elements
 *    inside this task.  Also, you cannot specify both match and a regular expression subelement at
 *    the same time, nor can you specify the replace attribute and the substitution subelement at
 *    the same time.
 *
 *   Attributes:
 *
 *     file    --> A single file to operation on (mutually exclusive
 *                    with the fileset subelements)
 *     match   --> The Regular expression to match
 *     replace --> The Expression replacement string
 *     flags   --> The options to give to the replacement
 *                 g = Substitute all occurrences. default is to replace only the first one
 *                 i = Case insensitive match
 *
 *     byline  --> Should this file be processed a single line at a time (default is false)
 *                 "true" indicates to perform replacement on a line by line basis
 *                 "false" indicates to perform replacement on the whole file at once.
 *
 *  Example:
 *
 *     The following call could be used to replace an old property name in a ".properties"
 *     file with a new name.  In the replace attribute, you can refer to any part of the
 *     match expression in parenthesis using backslash followed by a number like '\1'.
 *
 *     <replaceregexp file="test.properties"
 *                    match="MyProperty=(.*)"
 *                    replace="NewProperty=\1"
 *                    byline="true" />
 *
 * </pre>
 *
 */
public class ReplaceRegExp extends Task {

    private File file;
    private String flags;
    private boolean byline;
    private Vector filesets; // Keep jdk 1.1 compliant so others can use this
    private RegularExpression regex;
    private Substitution subs;

    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    /**
     * Encoding to assume for the files
     */
    private String encoding = null;

    /** Default Constructor  */
    public ReplaceRegExp() {
        super();
        this.file = null;
        this.filesets = new Vector();
        this.flags = "";
        this.byline = false;

        this.regex = null;
        this.subs = null;
    }


    /**
     * file for which the regular expression should be replaced;
     * required unless a nested fileset is supplied.
     * @param file The file for which the reg exp should be replaced.
     */
    public void setFile(File file) {
        this.file = file;
    }


    /**
     * the regular expression pattern to match in the file(s);
     * required if no nested <regexp> is used
     * @param match the match attribute.
     */
    public void setMatch(String match) {
        if (regex != null) {
            throw new BuildException("Only one regular expression is allowed");
        }

        regex = new RegularExpression();
        regex.setPattern(match);
    }


    /**
     * The substitution pattern to place in the file(s) in place
     * of the regular expression.
     * Required if no nested <substitution> is used
     * @param replace the replace attribute
     */

    public void setReplace(String replace) {
        if (subs != null) {
            throw new BuildException("Only one substitution expression is "
                                     + "allowed");
        }

        subs = new Substitution();
        subs.setExpression(replace);
    }

    /**
     * The flags to use when matching the regular expression.  For more
     * information, consult the Perl5 syntax.
     * <ul>
     *  <li>g : Global replacement.  Replace all occurrences found
     *  <li>i : Case Insensitive.  Do not consider case in the match
     *  <li>m : Multiline.  Treat the string as multiple lines of input,
     *         using "^" and "$" as the start or end of any line, respectively,
     *         rather than start or end of string.
     *  <li> s : Singleline.  Treat the string as a single line of input, using
     *        "." to match any character, including a newline, which normally,
     *        it would not match.
     *</ul>
     * @param flags the flags attribute
     */
    public void setFlags(String flags) {
        this.flags = flags;
    }


    /**
     * Process the file(s) one line at a time, executing the replacement
     * on one line at a time.  This is useful if you
     * want to only replace the first occurrence of a regular expression on
     * each line, which is not easy to do when processing the file as a whole.
     * Defaults to <i>false.
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