| /* |
| * 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.types.Parameter; |
| |
| /** |
| * Attaches a prefix to every line. |
| * |
| * Example: |
| * <pre><prefixlines prefix="Foo"/></pre> |
| * |
| * Or: |
| * |
| * <pre><filterreader classname="org.apache.tools.ant.filters.PrefixLines"> |
| * <param name="prefix" value="Foo"/> |
| * </filterreader></pre> |
| * |
| */ |
| public final class PrefixLines |
| extends BaseParamFilterReader |
| implements ChainableReader { |
| /** Parameter name for the prefix. */ |
| private static final String PREFIX_KEY = "prefix"; |
| |
| /** The prefix to be used. */ |
| private String prefix = null; |
| |
| /** Data that must be read from, if not null. */ |
| private String queuedData = null; |
| |
| /** |
| * Constructor for "dummy" instances. |
| * |
| * @see BaseFilterReader#BaseFilterReader() |
| */ |
| public PrefixLines() { |
| super(); |
| } |
| |
| /** |
| * Creates a new filtered reader. |
| * |
| * @param in A Reader object providing the underlying stream. |
| * Must not be <code>null</code>. |
| */ |
| public PrefixLines(final Reader in) { |
| super(in); |
| } |
| |
| /** |
| * Returns the next character in the filtered stream. One line is read |
| * from the original input, and the prefix added. The resulting |
| * line is then used until it ends, at which point the next original line |
| * is read, etc. |
| * |
| * @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 { |
| if (!getInitialized()) { |
| initialize(); |
| setInitialized(true); |
| } |
| |
| 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 = readLine(); |
| if (queuedData == null) { |
| ch = -1; |
| } else { |
| if (prefix != null) { |
| queuedData = prefix + queuedData; |
| } |
| return read(); |
| } |
| } |
| return ch; |
| } |
| |
| /** |
| * Sets the prefix to add at the start of each input line. |
| * |
| * @param prefix The prefix to add at the start of each input line. |
| * May be <code>null</code>, in which case no prefix |
| * is added. |
| */ |
| public void setPrefix(final String prefix) { |
| this.prefix = prefix; |
| } |
| |
| /** |
| * Returns the prefix which will be added at the start of each input line. |
| * |
| * @return the prefix which will be added at the start of each input line |
| */ |
| private String getPrefix() { |
| return prefix; |
| } |
| |
| /** |
| * Creates a new PrefixLines 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 Reader chain(final Reader rdr) { |
| PrefixLines newFilter = new PrefixLines(rdr); |
| newFilter.setPrefix(getPrefix()); |
| newFilter.setInitialized(true); |
| return newFilter; |
| } |
| |
| /** |
| * Initializes the prefix if it is available from the parameters. |
| */ |
| private void initialize() { |
| Parameter[] params = getParameters(); |
| if (params != null) { |
| for (int i = 0; i < params.length; i++) { |
| if (PREFIX_KEY.equals(params[i].getName())) { |
| prefix = params[i].getValue(); |
| break; |
| } |
| } |
| } |
| } |
| } |