Jetty example source code file (NIOBuffer.java)

This example Jetty source code file (NIOBuffer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Jetty tags/keywords

abstractbuffer, buffer, bytebuffer, bytebuffer, fileinputstream, illegalstateexception, illegalstateexception, inputstream, io, ioexception, ioexception, nio, niobuffer, niobuffer, readablebytechannel, writablebytechannel

The Jetty NIOBuffer.java source code

// ========================================================================
// Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at 
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========================================================================

package org.mortbay.io.nio;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;

import org.mortbay.io.AbstractBuffer;
import org.mortbay.io.Buffer;

/* ------------------------------------------------------------------------------- */
/** 
 * 
 * @author gregw
 */
public class NIOBuffer extends AbstractBuffer
{
  	public final static boolean 
  		DIRECT=true,
  		INDIRECT=false;
  	
    protected ByteBuffer _buf;
    private ReadableByteChannel _in;
    private InputStream _inStream;
    private WritableByteChannel _out;
    private OutputStream _outStream;

    public NIOBuffer(int size, boolean direct)
    {
        super(READWRITE,NON_VOLATILE);
        _buf = direct
        	?ByteBuffer.allocateDirect(size)
        	:ByteBuffer.allocate(size);
        _buf.position(0);
        _buf.limit(_buf.capacity());
    }
    
    /**
     * @param file
     */
    public NIOBuffer(File file) throws IOException
    {
        super(READONLY,NON_VOLATILE);
        FileInputStream fis = new FileInputStream(file);
        FileChannel fc = fis.getChannel();
        _buf = fc.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
        setGetIndex(0);
        setPutIndex((int)file.length());
        _access=IMMUTABLE;
    }

    public byte[] array()
    {
        if (!_buf.hasArray())
            return null;
        return _buf.array();
    }
    
    public int capacity()
    {
        return _buf.capacity();
    }

    public byte peek(int position)
    {
        return _buf.get(position);
    }

    public int peek(int index, byte[] b, int offset, int length)
    {
        int l = length;
        if (index+l > capacity())
            l=capacity()-index;
        if (l <= 0) 
            return -1;
        try
        {
            _buf.position(index);
            _buf.get(b,offset,l);
        }
        finally
        {
            _buf.position(0);
        }
        
        return l;
    }

    public void poke(int position, byte b)
    {
        if (isReadOnly()) throw new IllegalStateException(__READONLY);
        _buf.put(position,b);
    }

    public int poke(int index, Buffer src)
    {
        if (isReadOnly()) throw new IllegalStateException(__READONLY);
        
        byte[] array=src.array();
        if (array!=null)
        {
            int length = poke(index,array,src.getIndex(),src.length());
            return length;
        }
        else
        {
            Buffer src_buf=src.buffer();
            if (src_buf instanceof NIOBuffer)
            {
                ByteBuffer src_bytebuf = ((NIOBuffer)src_buf)._buf;
                if (src_bytebuf==_buf)
                    src_bytebuf=_buf.duplicate();
                try
                {   
                    _buf.position(index);
                    int space = _buf.remaining();
                    
                    int length=src.length();
                    if (length>space)    
                        length=space;
                    
                    src_bytebuf.position(src.getIndex());
                    src_bytebuf.limit(src.getIndex()+length);
                    
                    _buf.put(src_bytebuf);
                    return length;
                }
                finally
                {
                    _buf.position(0);
                    src_bytebuf.limit(src_bytebuf.capacity());
                    src_bytebuf.position(0);
                }
            }
            else
                return super.poke(index,src);
        }
    }
    
    public int poke(int index, byte[] b, int offset, int length)
    {
        if (isReadOnly()) throw new IllegalStateException(__READONLY);
        try
        {
            _buf.position(index);
            
            int space=_buf.remaining();
            
            if (length>space)
                length=space;
            if (length>0)
                _buf.put(b,offset,length);
            return length;
        }
        finally
        {
            _buf.position(0);
        }
    }
    
    public ByteBuffer getByteBuffer()
    {
        return _buf;
    }
    
    
    public void setByteBuffer(ByteBuffer buf)
    {
        this._buf = buf;
    }


    /* ------------------------------------------------------------ */
    public int readFrom(InputStream in, int max) throws IOException
    {
        if (_in==null || !_in.isOpen() || in!=_inStream)
        {
            _in=Channels.newChannel(in);
            _inStream=in;
        }

        if (max<0 || max>space())
            max=space();
        int p = putIndex();
        
        try
        {
            int len=0, total=0, available=max;
            int loop=0;
            while (total<max) 
            {
                _buf.position(p);
                _buf.limit(p+available);
                len=_in.read(_buf);
                if (len<0)
                {
                    _in=null;
                    _inStream=in;
                    break;
                }
                else if (len>0)
                {
                    p += len;
                    total += len;
                    available -= len;
                    setPutIndex(p);
                    loop=0;
                }
                else if (loop++>1)
                    break;
                if (in.available()<=0)
                    break;
            }
            if (len<0 && total==0)
                return -1;
            return total;
            
        }
        catch(IOException e)
        {
            _in=null;
            _inStream=in;
            throw e;
        }
        finally
        {
            if (_in!=null && !_in.isOpen())
            {
                _in=null;
                _inStream=in;
            }
            _buf.position(0);
            _buf.limit(_buf.capacity());
        }
    }

    /* ------------------------------------------------------------ */
    public void writeTo(OutputStream out) throws IOException
    {
        if (_out==null || !_out.isOpen() || _out!=_outStream)
        {
            _out=Channels.newChannel(out);
            _outStream=out;
        }

        try
        {
            int loop=0;
            while(hasContent() && _out.isOpen())
            {
                _buf.position(getIndex());
                _buf.limit(putIndex());
                int len=_out.write(_buf);
                if (len<0)
                    break;
                else if (len>0)
                {
                    skip(len);
                    loop=0;
                }
                else if (loop++>1)
                    break;
            }
        }
        catch(IOException e)
        {
            _out=null;
            _outStream=null;
            throw e;
        }
        finally
        {
            if (_out!=null && !_out.isOpen())
            {
                _out=null;
                _outStream=null;
            }
            _buf.position(0);
            _buf.limit(_buf.capacity());
        }
        
    }
    
    
}