/* * 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 sun.misc; 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 <tt>null</tt> otherwise.     */    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;    }}