/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Ant", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
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*
* 5. Products derived from this software may not be called "Apache"
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*
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.tools.ant.filters;
import java.io.IOException;
import java.io.Reader;
import java.util.Vector;
import org.apache.tools.ant.types.Parameter;
import org.apache.tools.ant.types.RegularExpression;
import org.apache.tools.ant.util.regexp.Regexp;
/**
* Filter which includes only those lines that contain the user-specified
* regular expression matching strings.
*
* Example:
* <pre><linecontainsregexp>
* <regexp pattern="foo*">
* </linecontainsregexp></pre>
*
* Or:
*
* <pre><filterreader classname="org.apache.tools.ant.filters.LineContainsRegExp">
* <param type="regexp" value="foo*"/>
* </filterreader></pre>
*
* This will fetch all those lines that contain the pattern <code>foo</code>
*
* @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
*/
public final class LineContainsRegExp
extends BaseParamFilterReader
implements ChainableReader {
/** Parameter name for the regular expression to filter on. */
private static final String REGEXP_KEY = "regexp";
/** Vector that holds the expressions that input lines must contain. */
private Vector regexps = new Vector();
/**
* Remaining line to be read from this filter, or <code>null</code> if
* the next call to <code>read()</code> should read the original stream
* to find the next matching line.
*/
private String line = null;
/**
* Constructor for "dummy" instances.
*
* @see BaseFilterReader#BaseFilterReader()
*/
public LineContainsRegExp() {
super();
}
/**
* Creates a new filtered reader.
*
* @param in A Reader object providing the underlying stream.
* Must not be <code>null</code>.
*/
public LineContainsRegExp(final Reader in) {
super(in);
}
/**
* Returns the next character in the filtered stream, only including
* lines from the original stream which match all of the specified
* regular expressions.
*
* @return the next character in the resulting stream, or -1
* if the end of the resulting stream has been reached
*
* @exception IOException if the underlying stream throws an IOException
* during reading
*/
public final int read() throws IOException {
if (!getInitialized()) {
initialize();
setInitialized(true);
}
int ch = -1;
if (line != null) {
ch = line.charAt(0);
if (line.length() == 1) {
line = null;
} else {
line = line.substring(1);
}
} else {
line = readLine();
if (line == null) {
ch = -1;
} else {
final int regexpsSize = regexps.size();
for (int i = 0; i < regexpsSize; i++) {
RegularExpression regexp = (RegularExpression)
regexps.elementAt(i);
Regexp re = regexp.getRegexp(getProject());
boolean matches = re.matches(line);
if (!matches) {
line = null;
break;
}
}
return read();
}
}
return ch;
}
/**
* Adds a <code>regexp</code> element.
*
* @param regExp The <code>regexp</code> element to add.
* Must not be <code>null</code>.
*/
public final void addConfiguredRegexp(final RegularExpression regExp) {
this.regexps.addElement(regExp);
}
/**
* Sets the vector of regular expressions which must be contained within
* a line read from the original stream in order for it to match this
* filter.
*
* @param regexps A vector of regular expressions which must be contained
* within a line in order for it to match in this filter. Must not be
* <code>null</code>.
*/
private void setRegexps(final Vector regexps) {
this.regexps = regexps;
}
/**
* Returns the vector of regular expressions which must be contained within
* a line read from the original stream in order for it to match this
* filter.
*
* @return the vector of regular expressions which must be contained within
* a line read from the original stream in order for it to match this
* filter. The returned object is "live" - in other words, changes made to
* the returned object are mirrored in the filter.
*/
private final Vector getRegexps() {
return regexps;
}
/**
* Creates a new LineContainsRegExp using the passed in
* Reader for instantiation.
*
* @param rdr A Reader object providing the underlying stream.
* Must not be <code>null</code>.
*
* @return a new filter based on this configuration, but filtering
* the specified reader
*/
public final Reader chain(final Reader rdr) {
LineContainsRegExp newFilter = new LineContainsRegExp(rdr);
newFilter.setRegexps(getRegexps());
newFilter.setInitialized(true);
return newFilter;
}
/**
* Parses parameters to add user defined regular expressions.
*/
private final void initialize() {
Parameter[] params = getParameters();
if (params != null) {
for (int i = 0; i < params.length; i++) {
if (REGEXP_KEY.equals(params[i].getType())) {
String pattern = params[i].getValue();
RegularExpression regexp = new RegularExpression();
regexp.setPattern(pattern);
regexps.addElement(regexp);
}
}
}
}
}