1 | /*
|
---|
2 | * Copyright 2002,2004 The Apache Software Foundation
|
---|
3 | *
|
---|
4 | * Licensed under the Apache License, Version 2.0 (the "License");
|
---|
5 | * you may not use this file except in compliance with the License.
|
---|
6 | * You may obtain a copy of the License at
|
---|
7 | *
|
---|
8 | * http://www.apache.org/licenses/LICENSE-2.0
|
---|
9 | *
|
---|
10 | * Unless required by applicable law or agreed to in writing, software
|
---|
11 | * distributed under the License is distributed on an "AS IS" BASIS,
|
---|
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
---|
13 | * See the License for the specific language governing permissions and
|
---|
14 | * limitations under the License.
|
---|
15 | *
|
---|
16 | */
|
---|
17 | package org.apache.tools.ant.filters;
|
---|
18 |
|
---|
19 | import java.io.IOException;
|
---|
20 | import java.io.Reader;
|
---|
21 | import org.apache.tools.ant.types.Parameter;
|
---|
22 |
|
---|
23 | /**
|
---|
24 | * Attaches a prefix to every line.
|
---|
25 | *
|
---|
26 | * Example:
|
---|
27 | * <pre><prefixlines prefix="Foo"/></pre>
|
---|
28 | *
|
---|
29 | * Or:
|
---|
30 | *
|
---|
31 | * <pre><filterreader classname="org.apache.tools.ant.filters.PrefixLines">
|
---|
32 | * <param name="prefix" value="Foo"/>
|
---|
33 | * </filterreader></pre>
|
---|
34 | *
|
---|
35 | */
|
---|
36 | public final class PrefixLines
|
---|
37 | extends BaseParamFilterReader
|
---|
38 | implements ChainableReader {
|
---|
39 | /** Parameter name for the prefix. */
|
---|
40 | private static final String PREFIX_KEY = "prefix";
|
---|
41 |
|
---|
42 | /** The prefix to be used. */
|
---|
43 | private String prefix = null;
|
---|
44 |
|
---|
45 | /** Data that must be read from, if not null. */
|
---|
46 | private String queuedData = null;
|
---|
47 |
|
---|
48 | /**
|
---|
49 | * Constructor for "dummy" instances.
|
---|
50 | *
|
---|
51 | * @see BaseFilterReader#BaseFilterReader()
|
---|
52 | */
|
---|
53 | public PrefixLines() {
|
---|
54 | super();
|
---|
55 | }
|
---|
56 |
|
---|
57 | /**
|
---|
58 | * Creates a new filtered reader.
|
---|
59 | *
|
---|
60 | * @param in A Reader object providing the underlying stream.
|
---|
61 | * Must not be <code>null</code>.
|
---|
62 | */
|
---|
63 | public PrefixLines(final Reader in) {
|
---|
64 | super(in);
|
---|
65 | }
|
---|
66 |
|
---|
67 | /**
|
---|
68 | * Returns the next character in the filtered stream. One line is read
|
---|
69 | * from the original input, and the prefix added. The resulting
|
---|
70 | * line is then used until it ends, at which point the next original line
|
---|
71 | * is read, etc.
|
---|
72 | *
|
---|
73 | * @return the next character in the resulting stream, or -1
|
---|
74 | * if the end of the resulting stream has been reached
|
---|
75 | *
|
---|
76 | * @exception IOException if the underlying stream throws an IOException
|
---|
77 | * during reading
|
---|
78 | */
|
---|
79 | public final int read() throws IOException {
|
---|
80 | if (!getInitialized()) {
|
---|
81 | initialize();
|
---|
82 | setInitialized(true);
|
---|
83 | }
|
---|
84 |
|
---|
85 | int ch = -1;
|
---|
86 |
|
---|
87 | if (queuedData != null && queuedData.length() == 0) {
|
---|
88 | queuedData = null;
|
---|
89 | }
|
---|
90 |
|
---|
91 | if (queuedData != null) {
|
---|
92 | ch = queuedData.charAt(0);
|
---|
93 | queuedData = queuedData.substring(1);
|
---|
94 | if (queuedData.length() == 0) {
|
---|
95 | queuedData = null;
|
---|
96 | }
|
---|
97 | } else {
|
---|
98 | queuedData = readLine();
|
---|
99 | if (queuedData == null) {
|
---|
100 | ch = -1;
|
---|
101 | } else {
|
---|
102 | if (prefix != null) {
|
---|
103 | queuedData = prefix + queuedData;
|
---|
104 | }
|
---|
105 | return read();
|
---|
106 | }
|
---|
107 | }
|
---|
108 | return ch;
|
---|
109 | }
|
---|
110 |
|
---|
111 | /**
|
---|
112 | * Sets the prefix to add at the start of each input line.
|
---|
113 | *
|
---|
114 | * @param prefix The prefix to add at the start of each input line.
|
---|
115 | * May be <code>null</code>, in which case no prefix
|
---|
116 | * is added.
|
---|
117 | */
|
---|
118 | public final void setPrefix(final String prefix) {
|
---|
119 | this.prefix = prefix;
|
---|
120 | }
|
---|
121 |
|
---|
122 | /**
|
---|
123 | * Returns the prefix which will be added at the start of each input line.
|
---|
124 | *
|
---|
125 | * @return the prefix which will be added at the start of each input line
|
---|
126 | */
|
---|
127 | private final String getPrefix() {
|
---|
128 | return prefix;
|
---|
129 | }
|
---|
130 |
|
---|
131 | /**
|
---|
132 | * Creates a new PrefixLines filter using the passed in
|
---|
133 | * Reader for instantiation.
|
---|
134 | *
|
---|
135 | * @param rdr A Reader object providing the underlying stream.
|
---|
136 | * Must not be <code>null</code>.
|
---|
137 | *
|
---|
138 | * @return a new filter based on this configuration, but filtering
|
---|
139 | * the specified reader
|
---|
140 | */
|
---|
141 | public final Reader chain(final Reader rdr) {
|
---|
142 | PrefixLines newFilter = new PrefixLines(rdr);
|
---|
143 | newFilter.setPrefix(getPrefix());
|
---|
144 | newFilter.setInitialized(true);
|
---|
145 | return newFilter;
|
---|
146 | }
|
---|
147 |
|
---|
148 | /**
|
---|
149 | * Initializes the prefix if it is available from the parameters.
|
---|
150 | */
|
---|
151 | private final void initialize() {
|
---|
152 | Parameter[] params = getParameters();
|
---|
153 | if (params != null) {
|
---|
154 | for (int i = 0; i < params.length; i++) {
|
---|
155 | if (PREFIX_KEY.equals(params[i].getName())) {
|
---|
156 | prefix = params[i].getValue();
|
---|
157 | break;
|
---|
158 | }
|
---|
159 | }
|
---|
160 | }
|
---|
161 | }
|
---|
162 | }
|
---|