/*
* 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
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* 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 org.apache.tools.ant.Project;
/**
* Expands Ant properties, if any, in the data.
* <p>
* Example:<br>
* <pre><expandproperties/></pre>
* Or:
* <pre><filterreader classname="org.apache.tools.ant.filters.ExpandProperties"/></pre>
*
* @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
*/
public final class ExpandProperties
extends BaseFilterReader
implements ChainableReader {
/** Data that must be read from, if not null. */
private String queuedData = null;
/**
* Constructor for "dummy" instances.
*
* @see BaseFilterReader#BaseFilterReader()
*/
public ExpandProperties() {
super();
}
/**
* Creates a new filtered reader.
*
* @param in A Reader object providing the underlying stream.
* Must not be <code>null</code>.
*/
public ExpandProperties(final Reader in) {
super(in);
}
/**
* Returns the next character in the filtered stream. The original
* stream is first read in fully, and the Ant properties are expanded.
* The results of this expansion are then queued so they can be read
* character-by-character.
*
* @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 {
int ch = -1;
if (queuedData != null && queuedData.length() == 0) {
queuedData = null;
}
if (queuedData != null) {
ch = queuedData.charAt(0);
queuedData = queuedData.substring(1);
if (queuedData.length() == 0) {
queuedData = null;
}
} else {
queuedData = readFully();
if (queuedData == null) {
ch = -1;
} else {
Project project = getProject();
queuedData = project.replaceProperties(queuedData);
return read();
}
}
return ch;
}
/**
* Creates a new ExpandProperties filter 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) {
ExpandProperties newFilter = new ExpandProperties(rdr);
newFilter.setProject(getProject());
return newFilter;
}
}