| /* |
| * 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.util; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.Reader; |
| |
| /** |
| * Adapts a <code>Reader</code> as an <code>InputStream</code>. |
| * Adapted from <code>StringInputStream</code>. |
| * |
| */ |
| public class ReaderInputStream extends InputStream { |
| private static final int BYTE_MASK = 0xFF; |
| |
| /** Source Reader */ |
| private Reader in; |
| |
| private String encoding = System.getProperty("file.encoding"); |
| |
| private byte[] slack; |
| |
| private int begin; |
| |
| /** |
| * Construct a <code>ReaderInputStream</code> |
| * for the specified <code>Reader</code>. |
| * |
| * @param reader <code>Reader</code>. Must not be <code>null</code>. |
| */ |
| public ReaderInputStream(Reader reader) { |
| in = reader; |
| } |
| |
| /** |
| * Construct a <code>ReaderInputStream</code> |
| * for the specified <code>Reader</code>, |
| * with the specified encoding. |
| * |
| * @param reader non-null <code>Reader</code>. |
| * @param encoding non-null <code>String</code> encoding. |
| */ |
| public ReaderInputStream(Reader reader, String encoding) { |
| this(reader); |
| if (encoding == null) { |
| throw new IllegalArgumentException("encoding must not be null"); |
| } else { |
| this.encoding = encoding; |
| } |
| } |
| |
| /** |
| * Reads from the <code>Reader</code>, returning the same value. |
| * |
| * @return the value of the next character in the <code>Reader</code>. |
| * |
| * @exception IOException if the original <code>Reader</code> fails to be read |
| */ |
| public synchronized int read() throws IOException { |
| if (in == null) { |
| throw new IOException("Stream Closed"); |
| } |
| |
| byte result; |
| if (slack != null && begin < slack.length) { |
| result = slack[begin]; |
| if (++begin == slack.length) { |
| slack = null; |
| } |
| } else { |
| byte[] buf = new byte[1]; |
| if (read(buf, 0, 1) <= 0) { |
| return -1; |
| } else { |
| result = buf[0]; |
| } |
| } |
| return result & BYTE_MASK; |
| } |
| |
| /** |
| * Reads from the <code>Reader</code> into a byte array |
| * |
| * @param b the byte array to read into |
| * @param off the offset in the byte array |
| * @param len the length in the byte array to fill |
| * @return the actual number read into the byte array, -1 at |
| * the end of the stream |
| * @exception IOException if an error occurs |
| */ |
| public synchronized int read(byte[] b, int off, int len) |
| throws IOException { |
| if (in == null) { |
| throw new IOException("Stream Closed"); |
| } |
| if (len == 0) { |
| return 0; |
| } |
| while (slack == null) { |
| char[] buf = new char[len]; // might read too much |
| int n = in.read(buf); |
| if (n == -1) { |
| return -1; |
| } |
| if (n > 0) { |
| slack = new String(buf, 0, n).getBytes(encoding); |
| begin = 0; |
| } |
| } |
| |
| if (len > slack.length - begin) { |
| len = slack.length - begin; |
| } |
| |
| System.arraycopy(slack, begin, b, off, len); |
| |
| begin += len; |
| if (begin >= slack.length) { |
| slack = null; |
| } |
| |
| return len; |
| } |
| |
| /** |
| * Marks the read limit of the Reader. |
| * |
| * @param limit the maximum limit of bytes that can be read before the |
| * mark position becomes invalid |
| */ |
| public synchronized void mark(final int limit) { |
| try { |
| in.mark(limit); |
| } catch (IOException ioe) { |
| throw new RuntimeException(ioe.getMessage()); |
| } |
| } |
| |
| |
| /** |
| * @return the current number of bytes ready for reading |
| * @exception IOException if an error occurs |
| */ |
| public synchronized int available() throws IOException { |
| if (in == null) { |
| throw new IOException("Stream Closed"); |
| } |
| if (slack != null) { |
| return slack.length - begin; |
| } |
| if (in.ready()) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| /** |
| * @return false - mark is not supported |
| */ |
| public boolean markSupported () { |
| return false; // would be imprecise |
| } |
| |
| /** |
| * Resets the Reader. |
| * |
| * @exception IOException if the Reader fails to be reset |
| */ |
| public synchronized void reset() throws IOException { |
| if (in == null) { |
| throw new IOException("Stream Closed"); |
| } |
| slack = null; |
| in.reset(); |
| } |
| |
| /** |
| * Closes the Reader. |
| * |
| * @exception IOException if the original Reader fails to be closed |
| */ |
| public synchronized void close() throws IOException { |
| if (in != null) { |
| in.close(); |
| slack = null; |
| in = null; |
| } |
| } |
| } |