org.glassfish.grizzly.websockets.Utils Maven / Gradle / Ivy

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 *
 * Copyright (c) 2013-2014 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
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 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 */
package org.glassfish.grizzly.websockets;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.WriteListener;

public final class Utils {

    static final ServletInputStream NULL_SERVLET_INPUT_STREAM =
            new ServletInputStream() {

        @Override
        public int read() throws IOException {
            return -1;
        }

        @Override
        public boolean isFinished() {
            return true;
        }

        @Override
        public boolean isReady() {
            return true;
        }

        @Override
        public void setReadListener(final ReadListener readListener) {
            try {
                readListener.onAllDataRead();
            } catch (IOException e) {
                readListener.onError(e);
            }
        }
    };
    
    static final Reader NULL_READER = new Reader() {

        @Override
        public int read(char[] cbuf, int off, int len) throws IOException {
            return -1;
        }

        @Override
        public void close() throws IOException {
        }

    };
    
    static final ServletOutputStream NULL_SERVLET_OUTPUT_STREAM = new ServletOutputStream() {
        private IOException ioe1;
        private IOException ioe2;
                
        @Override
        public boolean isReady() {
            return true;
        }

        @Override
        public void setWriteListener(final WriteListener writeListener) {
            // we don't care if ioe1 will be initialized several times because of thread racing
            if (ioe1 == null) {
                ioe1 = new IOException("Can't write to a websocket using ServletOutputStream");
            }
            
            writeListener.onError(ioe1);
        }

        @Override
        public void write(final int b) throws IOException {
            // we don't care if ioe2 will be initialized several times because of thread racing
            if (ioe2 == null) {
                ioe2 = new IOException("Can't write to a websocket using ServletOutputStream");
            }
            
            throw ioe2;
        }
    };
    
    static final Writer NULL_WRITER = new Writer() {
        private IOException ioe;

        @Override
        public void write(char[] cbuf, int off, int len) throws IOException {
            // we don't care if ioe will be initialized several times because of thread racing
            if (ioe == null) {
                ioe = new IOException("Can't write to a websocket using ServletWriter");
            }
            
            throw ioe;
        }

        @Override
        public void flush() throws IOException {
        }

        @Override
        public void close() throws IOException {
        }
        
    };
    
    public static byte[] toArray(long length) {
        long value = length;
        byte[] b = new byte[8];
        for (int i = 7; i >= 0 && value > 0; i--) {
            b[i] = (byte) (value & 0xFF);
            value >>= 8;
        }
        return b;
    }

    public static long toLong(byte[] bytes, int start, int end) {
        long value = 0;
        for (int i = start; i < end; i++) {
            value <<= 8;
            value ^= (long) bytes[i] & 0xFF;
        }
        return value;
    }

    public static List toString(byte[] bytes) {
        return toString(bytes, 0, bytes.length);
    }

    public static List toString(byte[] bytes, int start, int end) {
        List list = new ArrayList();
        for (int i = start; i < end; i++) {
            list.add(Integer.toHexString(bytes[i] & 0xFF).toUpperCase(Locale.US));
        }
        return list;
    }
}