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Kernel for Resin Java Application Server
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/*
* Copyright (c) 1998-2012 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.vfs;
import java.io.IOException;
/**
* A stream reading data from a string. The reader produces bytes using
* UTF-8.
*/
public class StringReader extends StreamImpl {
private String string;
private int length;
private int index;
private StringReader(String string)
{
// this.path = new NullPath("string");
this.string = string;
this.length = string.length();
this.index = 0;
}
/**
* Creates a new ReadStream reading bytes from the given string.
*
* @param string the source string.
*
* @return a ReadStream reading from the string.
*/
public static ReadStream open(String string)
{
StringReader ss = new StringReader(string);
ReadStream rs = new ReadStream(ss);
try {
rs.setEncoding("UTF-8");
} catch (Exception e) {
}
rs.setPath(new NullPath("string"));
return rs;
}
/**
* The string reader can always read.
*/
public boolean canRead()
{
return true;
}
public int read(byte []buf, int offset, int length)
throws IOException
{
char ch;
int i = 0;
for (; index < this.length && i < length; index++) {
ch = string.charAt(index);
if (ch < 0x80) {
buf[offset + i] = (byte) ch;
i++;
}
else if (i + 1 >= length)
break;
else if (ch < 0x800) {
buf[offset + i] = (byte) (0xc0 + (ch >> 6));
buf[offset + i + 1] = (byte) (0x80 + (ch & 0x3f));
i += 2;
}
else if (i + 2 >= length)
break;
else {
buf[offset + i] = (byte) (0xe0 + (ch >> 12));
buf[offset + i + 1] = (byte) (0x80 + ((ch >> 6) & 0x3f));
buf[offset + i + 2] = (byte) (0x80 + (ch & 0x3f));
i += 3;
}
}
return i > 0 ? i : -1;
}
/**
* Returns the number of characters available as an approximation to
* the number of bytes ready.
*/
public int getAvailable() throws IOException
{
return length - index;
}
}