/* 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 28, 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 FileInputStream extends InputStream
{
  /* Contains the file descriptor for referencing the actual file. */
  private FileDescriptor fd;

  public FileInputStream(String name) throws FileNotFoundException
  {
    SecurityManager s = System.getSecurityManager();
    if (s != null)
      s.checkRead(name);
    fd = new FileDescriptor(name, FileDescriptor.READ);
  }

  public FileInputStream(File file) throws FileNotFoundException
  {
    this(file.getPath());
  }

  public FileInputStream(FileDescriptor fdObj)
  {
    SecurityManager s = System.getSecurityManager();
    if (s != null)
      s.checkRead(fdObj);
    fd = fdObj;
  }

  public int available() throws IOException
  {
    return fd.available();
  }

  public void close() throws IOException
  {
    if (fd == null)
      return;

    fd.close();
    fd = null;
  }

  protected void finalize() throws IOException
  {
    if (fd != null)
      fd.finalize();
  }

  public final FileDescriptor getFD() throws IOException
  {
    if (!fd.valid())
      throw new IOException();
    return fd;
  }

  public int read() throws IOException
  {
    return fd.read();
  }

  public int read(byte[] b) throws IOException
  {
    return fd.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 ArrayIndexOutOfBoundsException();

    return fd.read(b, off, len);
  }

  public long skip(long n) throws IOException
  {
    return fd.seek(n, FileDescriptor.CUR);
  }
}