gcc/libjava/java/io/InputStream.java

105 lines
2.1 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 2, 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 abstract class InputStream
{
public InputStream()
{
}
public int available() throws IOException
{
return 0;
}
public void close() throws IOException
{
// Do nothing
}
public void mark(int readlimit)
{
// Do nothing
}
public boolean markSupported()
{
return false;
}
public abstract int read() throws IOException;
public int read(byte[] b) throws IOException
{
return read(b, 0, b.length);
}
public int read(byte[] b, int off, int len) throws IOException
{
if (off < 0 || len < 0 || off + len > b.length)
throw new IndexOutOfBoundsException();
if (b.length == 0)
return 0;
int i, ch;
for (i = 0; i < len; ++i)
try
{
if ((ch = read()) < 0)
return i == 0 ? -1 : i; // EOF
b[off + i] = (byte) ch;
}
catch (IOException ex)
{
// Only reading the first byte should cause an IOException.
if (i == 0)
throw ex;
return i;
}
return i;
}
public void reset() throws IOException
{
throw new IOException("mark/reset not supported");
}
public long skip(long n) throws IOException
{
// Throw away n bytes by reading them into a temp byte[].
// Limit the temp array to 2Kb so we don't grab too much memory.
final int buflen = n > 2048 ? 2048 : (int) n;
byte[] tmpbuf = new byte[buflen];
final long origN = n;
while (n > 0L)
{
int numread = read(tmpbuf, 0, n > buflen ? buflen : (int) n);
if (numread <= 0)
break;
n -= numread;
}
return origN - n;
}
}