[14627] | 1 | /*
|
---|
| 2 | * Copyright 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.util;
|
---|
| 18 |
|
---|
| 19 | import java.io.IOException;
|
---|
| 20 | import java.io.InputStream;
|
---|
| 21 | import java.io.Reader;
|
---|
| 22 |
|
---|
| 23 | /**
|
---|
| 24 | * Adapts a <code>Reader</code> as an <code>InputStream</code>.
|
---|
| 25 | * Adapted from <CODE>StringInputStream</CODE>.
|
---|
| 26 | *
|
---|
| 27 | */
|
---|
| 28 | public class ReaderInputStream extends InputStream {
|
---|
| 29 |
|
---|
| 30 | /** Source Reader */
|
---|
| 31 | private Reader in;
|
---|
| 32 |
|
---|
| 33 | private String encoding = System.getProperty("file.encoding");
|
---|
| 34 |
|
---|
| 35 | private byte[] slack;
|
---|
| 36 |
|
---|
| 37 | private int begin;
|
---|
| 38 |
|
---|
| 39 | /**
|
---|
| 40 | * Construct a <CODE>ReaderInputStream</CODE>
|
---|
| 41 | * for the specified <CODE>Reader</CODE>.
|
---|
| 42 | *
|
---|
| 43 | * @param reader <CODE>Reader</CODE>. Must not be <code>null</code>.
|
---|
| 44 | */
|
---|
| 45 | public ReaderInputStream(Reader reader) {
|
---|
| 46 | in = reader;
|
---|
| 47 | }
|
---|
| 48 |
|
---|
| 49 | /**
|
---|
| 50 | * Construct a <CODE>ReaderInputStream</CODE>
|
---|
| 51 | * for the specified <CODE>Reader</CODE>,
|
---|
| 52 | * with the specified encoding.
|
---|
| 53 | *
|
---|
| 54 | * @param reader non-null <CODE>Reader</CODE>.
|
---|
| 55 | * @param encoding non-null <CODE>String</CODE> encoding.
|
---|
| 56 | */
|
---|
| 57 | public ReaderInputStream(Reader reader, String encoding) {
|
---|
| 58 | this(reader);
|
---|
| 59 | if (encoding == null) {
|
---|
| 60 | throw new IllegalArgumentException("encoding must not be null");
|
---|
| 61 | } else {
|
---|
| 62 | this.encoding = encoding;
|
---|
| 63 | }
|
---|
| 64 | }
|
---|
| 65 |
|
---|
| 66 | /**
|
---|
| 67 | * Reads from the <CODE>Reader</CODE>, returning the same value.
|
---|
| 68 | *
|
---|
| 69 | * @return the value of the next character in the <CODE>Reader</CODE>.
|
---|
| 70 | *
|
---|
| 71 | * @exception IOException if the original <code>Reader</code> fails to be read
|
---|
| 72 | */
|
---|
| 73 | public synchronized int read() throws IOException {
|
---|
| 74 | if (in == null) {
|
---|
| 75 | throw new IOException("Stream Closed");
|
---|
| 76 | }
|
---|
| 77 |
|
---|
| 78 | byte result;
|
---|
| 79 | if (slack != null && begin < slack.length) {
|
---|
| 80 | result = slack[begin];
|
---|
| 81 | if (++begin == slack.length) {
|
---|
| 82 | slack = null;
|
---|
| 83 | }
|
---|
| 84 | } else {
|
---|
| 85 | byte[] buf = new byte[1];
|
---|
| 86 | if (read(buf, 0, 1) <= 0) {
|
---|
| 87 | result = -1;
|
---|
| 88 | }
|
---|
| 89 | result = buf[0];
|
---|
| 90 | }
|
---|
| 91 |
|
---|
| 92 | if (result < -1) {
|
---|
| 93 | result+= 256;
|
---|
| 94 | }
|
---|
| 95 |
|
---|
| 96 | return result;
|
---|
| 97 | }
|
---|
| 98 |
|
---|
| 99 | /**
|
---|
| 100 | * Reads from the <code>Reader</code> into a byte array
|
---|
| 101 | *
|
---|
| 102 | * @param b the byte array to read into
|
---|
| 103 | * @param off the offset in the byte array
|
---|
| 104 | * @param len the length in the byte array to fill
|
---|
| 105 | * @return the actual number read into the byte array, -1 at
|
---|
| 106 | * the end of the stream
|
---|
| 107 | * @exception IOException if an error occurs
|
---|
| 108 | */
|
---|
| 109 | public synchronized int read(byte[] b, int off, int len)
|
---|
| 110 | throws IOException {
|
---|
| 111 | if (in == null) {
|
---|
| 112 | throw new IOException("Stream Closed");
|
---|
| 113 | }
|
---|
| 114 |
|
---|
| 115 | while (slack == null) {
|
---|
| 116 | char[] buf = new char[len]; // might read too much
|
---|
| 117 | int n = in.read(buf);
|
---|
| 118 | if (n == -1) {
|
---|
| 119 | return -1;
|
---|
| 120 | }
|
---|
| 121 | if (n > 0) {
|
---|
| 122 | slack = new String(buf, 0, n).getBytes(encoding);
|
---|
| 123 | begin = 0;
|
---|
| 124 | }
|
---|
| 125 | }
|
---|
| 126 |
|
---|
| 127 | if (len > slack.length - begin) {
|
---|
| 128 | len = slack.length - begin;
|
---|
| 129 | }
|
---|
| 130 |
|
---|
| 131 | System.arraycopy(slack, begin, b, off, len);
|
---|
| 132 |
|
---|
| 133 | if ((begin += len) >= slack.length) {
|
---|
| 134 | slack = null;
|
---|
| 135 | }
|
---|
| 136 |
|
---|
| 137 | return len;
|
---|
| 138 | }
|
---|
| 139 |
|
---|
| 140 | /**
|
---|
| 141 | * Marks the read limit of the StringReader.
|
---|
| 142 | *
|
---|
| 143 | * @param limit the maximum limit of bytes that can be read before the
|
---|
| 144 | * mark position becomes invalid
|
---|
| 145 | */
|
---|
| 146 | public synchronized void mark(final int limit) {
|
---|
| 147 | try {
|
---|
| 148 | in.mark(limit);
|
---|
| 149 | } catch (IOException ioe) {
|
---|
| 150 | throw new RuntimeException(ioe.getMessage());
|
---|
| 151 | }
|
---|
| 152 | }
|
---|
| 153 |
|
---|
| 154 |
|
---|
| 155 | /**
|
---|
| 156 | * @return the current number of bytes ready for reading
|
---|
| 157 | * @exception IOException if an error occurs
|
---|
| 158 | */
|
---|
| 159 | public synchronized int available() throws IOException {
|
---|
| 160 | if (in == null) {
|
---|
| 161 | throw new IOException("Stream Closed");
|
---|
| 162 | }
|
---|
| 163 | if (slack != null) {
|
---|
| 164 | return slack.length - begin;
|
---|
| 165 | }
|
---|
| 166 | if (in.ready()) {
|
---|
| 167 | return 1;
|
---|
| 168 | } else {
|
---|
| 169 | return 0;
|
---|
| 170 | }
|
---|
| 171 | }
|
---|
| 172 |
|
---|
| 173 | /**
|
---|
| 174 | * @return false - mark is not supported
|
---|
| 175 | */
|
---|
| 176 | public boolean markSupported () {
|
---|
| 177 | return false; // would be imprecise
|
---|
| 178 | }
|
---|
| 179 |
|
---|
| 180 | /**
|
---|
| 181 | * Resets the StringReader.
|
---|
| 182 | *
|
---|
| 183 | * @exception IOException if the StringReader fails to be reset
|
---|
| 184 | */
|
---|
| 185 | public synchronized void reset() throws IOException {
|
---|
| 186 | if (in == null) {
|
---|
| 187 | throw new IOException("Stream Closed");
|
---|
| 188 | }
|
---|
| 189 | slack = null;
|
---|
| 190 | in.reset();
|
---|
| 191 | }
|
---|
| 192 |
|
---|
| 193 | /**
|
---|
| 194 | * Closes the Stringreader.
|
---|
| 195 | *
|
---|
| 196 | * @exception IOException if the original StringReader fails to be closed
|
---|
| 197 | */
|
---|
| 198 | public synchronized void close() throws IOException {
|
---|
| 199 | in.close();
|
---|
| 200 | slack = null;
|
---|
| 201 | in = null;
|
---|
| 202 | }
|
---|
| 203 | }
|
---|