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ReplaceRegExp.javaAPI DocApache Ant 1.7018433Wed Dec 13 06:16:18 GMT 2006org.apache.tools.ant.taskdefs.optional

ReplaceRegExp

public class ReplaceRegExp extends org.apache.tools.ant.Task
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 ant.regexp.regexpimpl will be the classname of the implementation that will be used (the default is org.apache.tools.ant.util.regexp.JakartaOroRegexp and requires the Jakarta Oro Package). 
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" />

Fields Summary
private File
file
private String
flags
private boolean
byline
private Vector
filesets
private org.apache.tools.ant.types.RegularExpression
regex
private org.apache.tools.ant.types.Substitution
subs
private static final org.apache.tools.ant.util.FileUtils
FILE_UTILS
private String
encoding
Encoding to assume for the files
Constructors Summary
public ReplaceRegExp()
Default Constructor


        
      
        super();
        this.file = null;
        this.filesets = new Vector();
        this.flags = "";
        this.byline = false;

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

Methods Summary
public voidaddFileset(org.apache.tools.ant.types.FileSet set)
list files to apply the replacement to

param
set the fileset element

        filesets.addElement(set);
public org.apache.tools.ant.types.RegularExpressioncreateRegexp()
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

        if (regex != null) {
            throw new BuildException("Only one regular expression is allowed.");
        }

        regex = new RegularExpression();
        return regex;
public org.apache.tools.ant.types.SubstitutioncreateSubstitution()
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

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

        subs = new Substitution();
        return subs;
protected java.lang.StringdoReplace(org.apache.tools.ant.types.RegularExpression r, org.apache.tools.ant.types.Substitution s, java.lang.String input, int options)
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

        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;
protected voiddoReplace(java.io.File f, int options)
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

        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();
            }
        }
public voidexecute()
Execute the task

throws
BuildException is there is a problem in the task execution.

        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);
                }
            }
        }
public voidsetByLine(java.lang.String byline)
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 false.
param
byline the byline attribute as a string
deprecated
since 1.6.x. Use setByLine(boolean).

        Boolean res = Boolean.valueOf(byline);

        if (res == null) {
            res = Boolean.FALSE;
        }
        this.byline = res.booleanValue();
public voidsetByLine(boolean byline)
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 false.
param
byline the byline attribute

        this.byline = byline;
public voidsetEncoding(java.lang.String encoding)
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

        this.encoding = encoding;
public voidsetFile(java.io.File file)
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.

        this.file = file;
public voidsetFlags(java.lang.String flags)
The flags to use when matching the regular expression. For more information, consult the Perl5 syntax.

param
flags the flags attribute

        this.flags = flags;
public voidsetMatch(java.lang.String match)
the regular expression pattern to match in the file(s); required if no nested <regexp> is used

param
match the match attribute.

        if (regex != null) {
            throw new BuildException("Only one regular expression is allowed");
        }

        regex = new RegularExpression();
        regex.setPattern(match);
public voidsetReplace(java.lang.String replace)
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

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

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