140 lines
3.2 KiB
Java
140 lines
3.2 KiB
Java
/* Copyright (C) 1998, 1999 Cygnus Solutions
|
|
|
|
This file is part of libgcj.
|
|
|
|
This software is copyrighted work licensed under the terms of the
|
|
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
|
|
details. */
|
|
|
|
package java.io;
|
|
|
|
/**
|
|
* @author Warren Levy <warrenl@cygnus.com>
|
|
* @date October 19, 1998.
|
|
*/
|
|
/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
|
|
* "The Java Language Specification", ISBN 0-201-63451-1
|
|
* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
|
|
* Status: Believed complete and correct
|
|
*/
|
|
|
|
public class StringReader extends Reader
|
|
{
|
|
/* A String provided by the creator of the stream. */
|
|
private String buf;
|
|
|
|
/* Position of the next char in buf to be read. */
|
|
private int pos;
|
|
|
|
/* The currently marked position in the stream. */
|
|
private int markedPos;
|
|
|
|
/* The index in buf one greater than the last valid character. */
|
|
private int count;
|
|
|
|
public StringReader(String buffer)
|
|
{
|
|
super();
|
|
buf = buffer;
|
|
|
|
count = buffer.length();
|
|
markedPos = pos = 0;
|
|
}
|
|
|
|
public void close()
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
buf = null;
|
|
}
|
|
}
|
|
|
|
public void mark(int readAheadLimit) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (buf == null)
|
|
throw new IOException();
|
|
|
|
// readAheadLimit is ignored per Java Class Lib. book, p. 1692.
|
|
markedPos = pos;
|
|
}
|
|
}
|
|
|
|
public boolean markSupported()
|
|
{
|
|
return true;
|
|
}
|
|
|
|
public int read() throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (buf == null)
|
|
throw new IOException();
|
|
|
|
if (pos < count)
|
|
return ((int) buf.charAt(pos++)) & 0xFFFF;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
public int read(char[] b, int off, int len) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (buf == null)
|
|
throw new IOException();
|
|
|
|
/* Don't need to check pos value, arraycopy will check it. */
|
|
if (off < 0 || len < 0 || off + len > b.length)
|
|
throw new ArrayIndexOutOfBoundsException();
|
|
|
|
if (pos >= count)
|
|
return -1;
|
|
|
|
int lastChar = Math.min(count, pos + len);
|
|
buf.getChars(pos, lastChar, b, off);
|
|
int numChars = lastChar - pos;
|
|
pos = lastChar;
|
|
return numChars;
|
|
}
|
|
}
|
|
|
|
public boolean ready() // TODO12: throws IOException
|
|
{
|
|
// TODO12: The JCL specifically says this returns true even if the
|
|
// reader has been closed, whereas the online 1.2 doc specifically
|
|
// says to throw an IOException if closed.
|
|
return true;
|
|
}
|
|
|
|
public void reset() throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (buf == null)
|
|
throw new IOException();
|
|
|
|
pos = markedPos;
|
|
}
|
|
}
|
|
|
|
public long skip(long n) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (buf == null)
|
|
throw new IOException();
|
|
|
|
// Even though the var numChars is a long, in reality it can never
|
|
// be larger than an int since the result of subtracting 2 positive
|
|
// ints will always fit in an int. Since we have to return a long
|
|
// anyway, numChars might as well just be a long.
|
|
long numChars = Math.min((long) (count - pos), n < 0 ? 0L : n);
|
|
pos += numChars;
|
|
return numChars;
|
|
}
|
|
}
|
|
}
|