| /* |
| * 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.directmemory.lightning.internal.io; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.Reader; |
| |
| public class ReaderInputStream |
| extends InputStream |
| { |
| |
| /** 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 |
| */ |
| @Override |
| 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 ) |
| { |
| result = -1; |
| } |
| result = buf[0]; |
| } |
| |
| if ( result < -1 ) |
| { |
| result += 256; |
| } |
| |
| return result; |
| } |
| |
| /** |
| * 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 |
| */ |
| @Override |
| public synchronized int read( byte[] b, int off, int len ) |
| throws IOException |
| { |
| if ( in == null ) |
| { |
| throw new IOException( "Stream Closed" ); |
| } |
| |
| 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 ); |
| |
| if ( ( begin += len ) >= slack.length ) |
| { |
| slack = null; |
| } |
| |
| return len; |
| } |
| |
| /** |
| * Marks the read limit of the StringReader. |
| * |
| * @param limit the maximum limit of bytes that can be read before the mark position becomes invalid |
| */ |
| @Override |
| 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 |
| */ |
| @Override |
| 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; |
| } |
| else |
| { |
| return 0; |
| } |
| } |
| |
| /** |
| * @return false - mark is not supported |
| */ |
| @Override |
| public boolean markSupported() |
| { |
| return false; // would be imprecise |
| } |
| |
| /** |
| * Resets the StringReader. |
| * |
| * @exception IOException if the StringReader fails to be reset |
| */ |
| @Override |
| public synchronized void reset() |
| throws IOException |
| { |
| if ( in == null ) |
| { |
| throw new IOException( "Stream Closed" ); |
| } |
| slack = null; |
| in.reset(); |
| } |
| |
| /** |
| * Closes the Stringreader. |
| * |
| * @exception IOException if the original StringReader fails to be closed |
| */ |
| @Override |
| public synchronized void close() |
| throws IOException |
| { |
| if ( in != null ) |
| { |
| in.close(); |
| slack = null; |
| in = null; |
| } |
| } |
| } |