mirror of git://gcc.gnu.org/git/gcc.git
148 lines
4.8 KiB
Java
148 lines
4.8 KiB
Java
/* ObjectInput.java -- Read object data from a stream
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Copyright (C) 1998 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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As a special exception, if you link this library with other files to
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produce an executable, this library does not by itself cause the
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resulting executable to be covered by the GNU General Public License.
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This exception does not however invalidate any other reasons why the
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executable file might be covered by the GNU General Public License. */
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package java.io;
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/**
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* This interface extends the <code>DataInput</code> interface to provide a
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* facility to read objects as well as primitive types from a stream. It
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* also has methods that allow input to be done in a manner similar to
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* <code>InputStream</code>
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*
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* @version 0.0
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*
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* @author Aaron M. Renn (arenn@urbanophile.com)
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*/
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public interface ObjectInput extends DataInput
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{
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/**
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* This method returns the number of bytes that can be read without
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* blocking.
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*
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* @return The number of bytes available before blocking
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*
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* @exception IOException If an error occurs
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*/
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public abstract int
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available() throws IOException;
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/*************************************************************************/
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/**
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* This method reading a byte of data from a stream. It returns that byte
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* as an int. This method blocks if no data is available to be read.
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*
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* @return The byte of data read
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*
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* @exception IOException If an error occurs
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*/
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public abstract int
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read() throws IOException;
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/*************************************************************************/
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/**
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* This method reads raw bytes and stores them them a byte array buffer.
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* Note that this method will block if no data is available. However,
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* it will not necessarily block until it fills the entire buffer. That is,
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* a "short count" is possible.
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*
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* @param buf The byte array to receive the data read
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*
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* @return The actual number fo bytes read or -1 if end of stream
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*
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* @exception IOException If an error occurs
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*/
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public abstract int
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read(byte[] buf) throws IOException;
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/*************************************************************************/
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/**
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* This method reads raw bytes and stores them in a byte array buffer
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* <code>buf</code> starting at position <code>offset</code> into the buffer. A
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* maximum of <code>len</code> bytes will be read. Note that this method
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* blocks if no data is available, but will not necessarily block until
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* it can read <code>len</code> bytes of data. That is, a "short count" is
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* possible.
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*
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* @param buf The byte array to receive the data read
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* @param offset The offset into @code{buf} to start storing data
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* @param len The maximum number of bytes to read
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*
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* @return The actual number fo bytes read or -1 if end of stream
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*
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* @exception IOException If an error occurs
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*/
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public abstract int
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read(byte[] buf, int offset, int len) throws IOException;
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/*************************************************************************/
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/**
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* Reads an object instance and returns it. If the class for the object
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* being read cannot be found, then a ClassNotFoundException will
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* be thrown.
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*
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* @return The object instance that was read
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*
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* @exception ClassNotFoundException If a class for the object cannot be found
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* @exception IOException If an error occurs
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*/
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public abstract Object
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readObject() throws ClassNotFoundException, IOException;
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/*************************************************************************/
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/**
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* This method causes the specified number of bytes to be read and
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* discarded. It is possible that fewer than the requested number of bytes
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* will actually be skipped.
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*
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* @param num_bytes The number of bytes to skip
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*
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* @return The actual number of bytes skipped
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*
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* @exception IOException If an error occurs
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*/
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public abstract long
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skip(long num_bytes) throws IOException;
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/*************************************************************************/
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/**
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* This method closes the input source
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*
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* @exception IOException If an error occurs
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*/
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public abstract void
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close() throws IOException;
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} // interface ObjectInput
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