| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| /* |
| * 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 com.sun.org.apache.xerces.internal.impl.io; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.Reader; |
| import java.util.Locale; |
| |
| import com.sun.org.apache.xerces.internal.impl.msg.XMLMessageFormatter; |
| import com.sun.org.apache.xerces.internal.util.MessageFormatter; |
| |
| /** |
| * <p> |
| * A UTF-16 reader. Can also be used for UCS-2 (i.e. ISO-10646-UCS-2).</p> |
| * |
| * @xerces.internal |
| * |
| * @author Michael Glavassevich, IBM |
| * |
| * @version $Id: UTF16Reader.java 718095 2008-11-16 20:00:14Z mrglavas $ |
| */ |
| public final class UTF16Reader |
| extends Reader { |
| |
| // |
| // Constants |
| // |
| /** |
| * Default byte buffer size (4096). |
| */ |
| public static final int DEFAULT_BUFFER_SIZE = 4096; |
| |
| // |
| // Data |
| // |
| /** |
| * Input stream. |
| */ |
| protected final InputStream fInputStream; |
| |
| /** |
| * Byte buffer. |
| */ |
| protected final byte[] fBuffer; |
| |
| /** |
| * Endianness. |
| */ |
| protected final boolean fIsBigEndian; |
| |
| // message formatter; used to produce localized exception messages |
| private final MessageFormatter fFormatter; |
| |
| // Locale to use for messages |
| private final Locale fLocale; |
| |
| // |
| // Constructors |
| // |
| /** |
| * Constructs a UTF-16 reader from the specified input stream using the |
| * default buffer size. Primarily for testing. |
| * |
| * @param inputStream The input stream. |
| * @param isBigEndian The byte order. |
| */ |
| public UTF16Reader(InputStream inputStream, boolean isBigEndian) { |
| this(inputStream, DEFAULT_BUFFER_SIZE, isBigEndian, |
| new XMLMessageFormatter(), Locale.getDefault()); |
| } // <init>(InputStream, boolean) |
| |
| /** |
| * Constructs a UTF-16 reader from the specified input stream using the |
| * default buffer size and the given MessageFormatter. |
| * |
| * @param inputStream The input stream. |
| * @param isBigEndian The byte order. |
| */ |
| public UTF16Reader(InputStream inputStream, boolean isBigEndian, |
| MessageFormatter messageFormatter, Locale locale) { |
| this(inputStream, DEFAULT_BUFFER_SIZE, isBigEndian, messageFormatter, locale); |
| } // <init>(InputStream, boolean, MessageFormatter, Locale) |
| |
| /** |
| * Constructs a UTF-16 reader from the specified input stream and buffer |
| * size and given MessageFormatter. |
| * |
| * @param inputStream The input stream. |
| * @param size The initial buffer size. |
| * @param isBigEndian The byte order. |
| * @param messageFormatter Given MessageFormatter |
| * @param locale Locale to use for messages |
| */ |
| public UTF16Reader(InputStream inputStream, int size, boolean isBigEndian, |
| MessageFormatter messageFormatter, Locale locale) { |
| this(inputStream, new byte[size], isBigEndian, messageFormatter, locale); |
| } // <init>(InputStream, int, boolean, MessageFormatter, Locale) |
| |
| /** |
| * Constructs a UTF-16 reader from the specified input stream, buffer and |
| * MessageFormatter. |
| * |
| * @param inputStream The input stream. |
| * @param buffer The byte buffer. |
| * @param isBigEndian The byte order. |
| * @param messageFormatter Given MessageFormatter |
| * @param locale Locale to use for messages |
| */ |
| public UTF16Reader(InputStream inputStream, byte[] buffer, boolean isBigEndian, |
| MessageFormatter messageFormatter, Locale locale) { |
| fInputStream = inputStream; |
| fBuffer = buffer; |
| fIsBigEndian = isBigEndian; |
| fFormatter = messageFormatter; |
| fLocale = locale; |
| } // <init>(InputStream, byte[], boolean, MessageFormatter, Locale) |
| |
| // |
| // Reader methods |
| // |
| /** |
| * Read a single character. This method will block until a character is |
| * available, an I/O error occurs, or the end of the stream is reached. |
| * |
| * <p> |
| * Subclasses that intend to support efficient single-character input should |
| * override this method. |
| * |
| * @return The character read, as an integer in the range 0 to 65535 |
| * (<tt>0x00-0xffff</tt>), or -1 if the end of the stream has been reached |
| * |
| * @exception IOException If an I/O error occurs |
| */ |
| public int read() throws IOException { |
| final int b0 = fInputStream.read(); |
| if (b0 == -1) { |
| return -1; |
| } |
| final int b1 = fInputStream.read(); |
| if (b1 == -1) { |
| expectedTwoBytes(); |
| } |
| // UTF-16BE |
| if (fIsBigEndian) { |
| return (b0 << 8) | b1; |
| } |
| // UTF-16LE |
| return (b1 << 8) | b0; |
| } // read():int |
| |
| /** |
| * Read characters into a portion of an array. This method will block until |
| * some input is available, an I/O error occurs, or the end of the stream is |
| * reached. |
| * |
| * @param ch Destination buffer |
| * @param offset Offset at which to start storing characters |
| * @param length Maximum number of characters to read |
| * |
| * @return The number of characters read, or -1 if the end of the stream has |
| * been reached |
| * |
| * @exception IOException If an I/O error occurs |
| */ |
| public int read(char ch[], int offset, int length) throws IOException { |
| int byteLength = length << 1; |
| if (byteLength > fBuffer.length) { |
| byteLength = fBuffer.length; |
| } |
| int byteCount = fInputStream.read(fBuffer, 0, byteLength); |
| if (byteCount == -1) { |
| return -1; |
| } |
| // If an odd number of bytes were read, we still need to read one more. |
| if ((byteCount & 1) != 0) { |
| int b = fInputStream.read(); |
| if (b == -1) { |
| expectedTwoBytes(); |
| } |
| fBuffer[byteCount++] = (byte) b; |
| } |
| final int charCount = byteCount >> 1; |
| if (fIsBigEndian) { |
| processBE(ch, offset, charCount); |
| } else { |
| processLE(ch, offset, charCount); |
| } |
| return charCount; |
| } // read(char[],int,int) |
| |
| /** |
| * Skip characters. This method will block until some characters are |
| * available, an I/O error occurs, or the end of the stream is reached. |
| * |
| * @param n The number of characters to skip |
| * |
| * @return The number of characters actually skipped |
| * |
| * @exception IOException If an I/O error occurs |
| */ |
| public long skip(long n) throws IOException { |
| long bytesSkipped = fInputStream.skip(n << 1); |
| if ((bytesSkipped & 1) != 0) { |
| int b = fInputStream.read(); |
| if (b == -1) { |
| expectedTwoBytes(); |
| } |
| ++bytesSkipped; |
| } |
| return bytesSkipped >> 1; |
| } // skip(long):long |
| |
| /** |
| * Tell whether this stream is ready to be read. |
| * |
| * @return True if the next read() is guaranteed not to block for input, |
| * false otherwise. Note that returning false does not guarantee that the |
| * next read will block. |
| * |
| * @exception IOException If an I/O error occurs |
| */ |
| public boolean ready() throws IOException { |
| return false; |
| } // ready() |
| |
| /** |
| * Tell whether this stream supports the mark() operation. |
| */ |
| public boolean markSupported() { |
| return false; |
| } // markSupported() |
| |
| /** |
| * Mark the present position in the stream. Subsequent calls to reset() will |
| * attempt to reposition the stream to this point. Not all character-input |
| * streams support the mark() operation. |
| * |
| * @param readAheadLimit Limit on the number of characters that may be read |
| * while still preserving the mark. After reading this many characters, |
| * attempting to reset the stream may fail. |
| * |
| * @exception IOException If the stream does not support mark(), or if some |
| * other I/O error occurs |
| */ |
| public void mark(int readAheadLimit) throws IOException { |
| throw new IOException(fFormatter.formatMessage(fLocale, "OperationNotSupported", new Object[]{"mark()", "UTF-16"})); |
| } // mark(int) |
| |
| /** |
| * Reset the stream. If the stream has been marked, then attempt to |
| * reposition it at the mark. If the stream has not been marked, then |
| * attempt to reset it in some way appropriate to the particular stream, for |
| * example by repositioning it to its starting point. Not all |
| * character-input streams support the reset() operation, and some support |
| * reset() without supporting mark(). |
| * |
| * @exception IOException If the stream has not been marked, or if the mark |
| * has been invalidated, or if the stream does not support reset(), or if |
| * some other I/O error occurs |
| */ |
| public void reset() throws IOException { |
| } // reset() |
| |
| /** |
| * Close the stream. Once a stream has been closed, further read(), ready(), |
| * mark(), or reset() invocations will throw an IOException. Closing a |
| * previously-closed stream, however, has no effect. |
| * |
| * @exception IOException If an I/O error occurs |
| */ |
| public void close() throws IOException { |
| fInputStream.close(); |
| } // close() |
| |
| // |
| // Private methods |
| // |
| /** |
| * Decodes UTF-16BE * |
| */ |
| private void processBE(final char ch[], int offset, final int count) { |
| int curPos = 0; |
| for (int i = 0; i < count; ++i) { |
| final int b0 = fBuffer[curPos++] & 0xff; |
| final int b1 = fBuffer[curPos++] & 0xff; |
| ch[offset++] = (char) ((b0 << 8) | b1); |
| } |
| } // processBE(char[],int,int) |
| |
| /** |
| * Decodes UTF-16LE * |
| */ |
| private void processLE(final char ch[], int offset, final int count) { |
| int curPos = 0; |
| for (int i = 0; i < count; ++i) { |
| final int b0 = fBuffer[curPos++] & 0xff; |
| final int b1 = fBuffer[curPos++] & 0xff; |
| ch[offset++] = (char) ((b1 << 8) | b0); |
| } |
| } // processLE(char[],int,int) |
| |
| /** |
| * Throws an exception for expected byte. |
| */ |
| private void expectedTwoBytes() |
| throws MalformedByteSequenceException { |
| throw new MalformedByteSequenceException(fFormatter, |
| fLocale, |
| XMLMessageFormatter.XML_DOMAIN, |
| "ExpectedByte", |
| new Object[]{"2", "2"}); |
| } // expectedTwoBytes() |
| |
| } // class UTF16Reader |