/*
* Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package jdk.internal.util.xml.impl;
import java.io.Reader;
import java.io.InputStream;
import java.io.IOException;
/**
* UTF-16 encoded stream reader.
*/
public class ReaderUTF16 extends Reader {
private InputStream is;
private char bo;
/**
* Constructor.
*
* Byte order argument can be: 'l' for little-endian or 'b' for big-endian.
*
* @param is A byte input stream.
* @param bo A byte order in the input stream.
*/
public ReaderUTF16(InputStream is, char bo) {
switch (bo) {
case 'l':
break;
case 'b':
break;
default:
throw new IllegalArgumentException("");
}
this.bo = bo;
this.is = is;
}
/**
* Reads characters into a portion of an array.
*
* @param cbuf Destination buffer.
* @param off Offset at which to start storing characters.
* @param len Maximum number of characters to read.
* @exception IOException If any IO errors occur.
*/
public int read(char[] cbuf, int off, int len) throws IOException {
int num = 0;
int val;
if (bo == 'b') {
while (num < len) {
if ((val = is.read()) < 0) {
return (num != 0) ? num : -1;
}
cbuf[off++] = (char) ((val << 8) | (is.read() & 0xff));
num++;
}
} else {
while (num < len) {
if ((val = is.read()) < 0) {
return (num != 0) ? num : -1;
}
cbuf[off++] = (char) ((is.read() << 8) | (val & 0xff));
num++;
}
}
return num;
}
/**
* Reads a single character.
*
* @return The character read, as an integer in the range 0 to 65535
* (0x0000-0xffff), or -1 if the end of the stream has been reached.
* @exception IOException If any IO errors occur.
*/
public int read() throws IOException {
int val;
if ((val = is.read()) < 0) {
return -1;
}
if (bo == 'b') {
val = (char) ((val << 8) | (is.read() & 0xff));
} else {
val = (char) ((is.read() << 8) | (val & 0xff));
}
return val;
}
/**
* Closes the stream.
*
* @exception IOException If any IO errors occur.
*/
public void close() throws IOException {
is.close();
}
}