Ant example source code file (ExpandProperties.java)

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Java - Ant tags/keywords

basefilterreader, chainablereader, expandproperties, expandproperties, io, ioexception, ioexception, project, project, reader, reader, string

The ExpandProperties.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.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/>

* Or: * <pre><filterreader * classname="org.apache.tools.ant.filters.ExpandProperties"/></pre> * */ 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. */ 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 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. * * @return a new filter based on this configuration, but filtering * the specified reader */ public Reader chain(final Reader rdr) { ExpandProperties newFilter = new ExpandProperties(rdr); newFilter.setProject(getProject()); return newFilter; } }