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	/*
	* Copyright (c) 1998, 2009, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package jdk.internal.loader;

	import java.io.EOFException;
	import java.net.URL;
	import java.io.IOException;
	import java.io.InterruptedIOException;
	import java.io.InputStream;
	import java.security.CodeSigner;
	import java.util.jar.Manifest;
	import java.nio.ByteBuffer;
	import java.util.Arrays;
	import sun.nio.ByteBuffered;

	/**
	* This class is used to represent a Resource that has been loaded
	* from the class path.
	*
	* @author David Connelly
	* @since 1.2
	*/
	public abstract class Resource {
	/**
	* Returns the name of the Resource.
	*/
	public abstract String getName();

	/**
	* Returns the URL of the Resource.
	*/
	public abstract URL getURL();

	/**
	* Returns the CodeSource URL for the Resource.
	*/
	public abstract URL getCodeSourceURL();

	/**
	* Returns an InputStream for reading the Resource data.
	*/
	public abstract InputStream getInputStream() throws IOException;

	/**
	* Returns the length of the Resource data, or -1 if unknown.
	*/
	public abstract int getContentLength() throws IOException;

	private InputStream cis;

	/* Cache result in case getBytes is called after getByteBuffer. */
	private synchronized InputStream cachedInputStream() throws IOException {
	if (cis == null) {
	cis = getInputStream();
	}
	return cis;
	}

	/**
	* Returns the Resource data as an array of bytes.
	*/
	public byte[] getBytes() throws IOException {
	byte[] b;
	// Get stream before content length so that a FileNotFoundException
	// can propagate upwards without being caught too early
	InputStream in = cachedInputStream();

	// This code has been uglified to protect against interrupts.
	// Even if a thread has been interrupted when loading resources,
	// the IO should not abort, so must carefully retry, failing only
	// if the retry leads to some other IO exception.

	boolean isInterrupted = Thread.interrupted();
	int len;
	for (;;) {
	try {
	len = getContentLength();
	break;
	} catch (InterruptedIOException iioe) {
	Thread.interrupted();
	isInterrupted = true;
	}
	}

	try {
	b = new byte[0];
	if (len == -1) len = Integer.MAX_VALUE;
	int pos = 0;
	while (pos < len) {
	int bytesToRead;
	if (pos >= b.length) { // Only expand when there's no room
	bytesToRead = Math.min(len - pos, b.length + 1024);
	if (b.length < pos + bytesToRead) {
	b = Arrays.copyOf(b, pos + bytesToRead);
	}
	} else {
	bytesToRead = b.length - pos;
	}
	int cc = 0;
	try {
	cc = in.read(b, pos, bytesToRead);
	} catch (InterruptedIOException iioe) {
	Thread.interrupted();
	isInterrupted = true;
	}
	if (cc < 0) {
	if (len != Integer.MAX_VALUE) {
	throw new EOFException("Detect premature EOF");
	} else {
	if (b.length != pos) {
	b = Arrays.copyOf(b, pos);
	}
	break;
	}
	}
	pos += cc;
	}
	} finally {
	try {
	in.close();
	} catch (InterruptedIOException iioe) {
	isInterrupted = true;
	} catch (IOException ignore) {}

	if (isInterrupted) {
	Thread.currentThread().interrupt();
	}
	}
	return b;
	}

	/**
	* Returns the Resource data as a ByteBuffer, but only if the input stream
	* was implemented on top of a ByteBuffer. Return {@code null} otherwise.
	* @return Resource data or null.
	*/
	public ByteBuffer getByteBuffer() throws IOException {
	InputStream in = cachedInputStream();
	if (in instanceof ByteBuffered) {
	return ((ByteBuffered)in).getByteBuffer();
	}
	return null;
	}

	/**
	* Returns the Manifest for the Resource, or null if none.
	*/
	public Manifest getManifest() throws IOException {
	return null;
	}

	/**
	* Returns theCertificates for the Resource, or null if none.
	*/
	public java.security.cert.Certificate[] getCertificates() {
	return null;
	}

	/**
	* Returns the code signers for the Resource, or null if none.
	*/
	public CodeSigner[] getCodeSigners() {
	return null;
	}
	}

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