OpenNxSerialization

/*
 * @(#)NxObjectOutputStream.java	1.0
 *
 * Created on September 18, 2008, 12:59 PM
 *
 * Copyright 2008 NeXtreme Innovations, Inc. All rights reserved.
 * "NeXtreme Innovations" PROPRIETARY/CONFIDENTIAL. Use is subject
 * to license terms.
 */

package com.nextreme.opennxserialization.standard.io;

import com.nextreme.opennxserialization.core.io.NxBlockDataOutputStream;
import com.nextreme.opennxserialization.core.io.NxObjectOutput;
import com.nextreme.opennxserialization.core.io.NxSerializationContext;
import com.nextreme.opennxserialization.core.io.NxTypeSurrogateSelector;
import com.nextreme.opennxserialization.core.io.surrogates.NxSerializationSurrogate;
import java.io.IOException;
import java.io.OutputStream;

/**
 * NxObjectOutputStream class.
 *
 * @version 1.0, September 18, 2008
 */
public class NxObjectOutputStream 
        extends OutputStream implements NxObjectOutput
{
    /**
     * working arrays initialized on demand by readUTF
     */
    private NxBlockDataOutputStream mOutput;
    private NxSerializationContext mContext;
    private NxTypeSurrogateSelector mSelector;
    
    /**
     * Creates an ObjectOutputStream that writes to the specified OutputStream.
     * This constructor writes the serialization stream header to the
     * underlying stream; callers may wish to flush the stream immediately to
     * ensure that constructors for receiving ObjectInputStreams will not block
     * when reading the header.
     *
     * <p>If a security manager is installed, this constructor will check for
     * the "enableSubclassImplementation" SerializablePermission when invoked
     * directly or indirectly by the constructor of a subclass which overrides
     * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
     * methods.
     *
     * @param	out output stream to write to
     * @throws	IOException if an I/O error occurs while writing stream header
     * @throws	SecurityException if untrusted subclass illegally overrides
     * 		security-sensitive methods
     * @throws	NullPointerException if <code>out</code> is <code>null</code>
     */
    public NxObjectOutputStream(OutputStream out) throws IOException {
        this.mOutput = new NxBlockDataOutputStream(out);
        this.mSelector = NxTypeSurrogateSelectorImpl.getDefault();
        this.mContext = new NxSerializationContext(this.mSelector);
        this.mContext.putUserItem("__bout", this.mOutput);
    }

    /**
     * Creates an ObjectOutputStream that writes to the specified OutputStream.
     * This constructor writes the serialization stream header to the
     * underlying stream; callers may wish to flush the stream immediately to
     * ensure that constructors for receiving ObjectInputStreams will not block
     * when reading the header.
     *
     * <p>If a security manager is installed, this constructor will check for
     * the "enableSubclassImplementation" SerializablePermission when invoked
     * directly or indirectly by the constructor of a subclass which overrides
     * the ObjectOutputStream.putFields or ObjectOutputStream.writeUnshared
     * methods.
     *
     * @param	out output stream to write to
     * @param	selector type surrogate selector to use
     * @throws	IOException if an I/O error occurs while writing stream header
     * @throws	SecurityException if untrusted subclass illegally overrides
     * 		security-sensitive methods
     * @throws	NullPointerException if <code>out</code> is <code>null</code>
     */
    public NxObjectOutputStream(OutputStream out, NxTypeSurrogateSelector selector) throws IOException {
        this.mOutput = new NxBlockDataOutputStream(out);
        this.mContext = new NxSerializationContext(selector);
        this.mSelector = this.mContext.getSurrogateSelector();
        this.mContext.putUserItem("__bout", this.mOutput);
    }


    /**
     * Returns the current <see cref="NxSerializationContext"/> object.
     *
     * @return the current serialzation context
     */
    public NxSerializationContext getContext() {
        return this.mContext;
    }

    /**
     * Returns the underlying InputStream object. 
     */
    public OutputStream getBaseStream() {
        return this.mOutput;
    }


    /**
     * Writes the specified byte (the low eight bits of the argument 
     * <code>b</code>) to the underlying output stream. If no exception 
     * is thrown, the counter <code>written</code> is incremented by 
     * <code>1</code>.
     * <p>
     * Implements the <code>write</code> method of <code>OutputStream</code>.
     *
     * @param      b   the <code>byte</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public synchronized void write(int b) throws IOException {
	this.mOutput.write(b);
    }
    
    /**
     * Writes <code>len</code> bytes from the specified byte array 
     * starting at offset <code>off</code> to the underlying output stream. 
     * If no exception is thrown, the counter <code>written</code> is 
     * incremented by <code>len</code>.
     *
     * @param      b     the data.
     * @param      off   the start offset in the data.
     * @param      len   the number of bytes to write.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    @Override
    public synchronized void write(byte b[], int off, int len)	throws IOException {
	this.mOutput.write(b, off, len);
    }

    /**
     * Flushes this data output stream. This forces any buffered output 
     * bytes to be written out to the stream. 
     * <p>
     * The <code>flush</code> method of <code>DataOutputStream</code>
     * calls the <code>flush</code> method of its underlying output stream.
     *
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     * @see        java.io.OutputStream#flush()
     */
    @Override
    public void flush() throws IOException {
	this.mOutput.flush();
    }

    /**
     * Writes a <code>boolean</code> to the underlying output stream as 
     * a 1-byte value. The value <code>true</code> is written out as the 
     * value <code>(byte)1</code>; the value <code>false</code> is 
     * written out as the value <code>(byte)0</code>. If no exception is 
     * thrown, the counter <code>written</code> is incremented by 
     * <code>1</code>.
     *
     * @param      v   a <code>boolean</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeBoolean(boolean v) throws IOException {
	this.mOutput.writeBoolean(v);
    }

    /**
     * Writes out a <code>byte</code> to the underlying output stream as 
     * a 1-byte value. If no exception is thrown, the counter 
     * <code>written</code> is incremented by <code>1</code>.
     *
     * @param      v   a <code>byte</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeByte(int v) throws IOException {
	this.mOutput.writeByte(v);
    }

    /**
     * Writes a <code>short</code> to the underlying output stream as two
     * bytes, high byte first. If no exception is thrown, the counter 
     * <code>written</code> is incremented by <code>2</code>.
     *
     * @param      v   a <code>short</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeShort(int v) throws IOException {
        this.mOutput.writeShort(v);
    }

    /**
     * Writes a <code>char</code> to the underlying output stream as a 
     * 2-byte value, high byte first. If no exception is thrown, the 
     * counter <code>written</code> is incremented by <code>2</code>.
     *
     * @param      v   a <code>char</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeChar(int v) throws IOException {
        this.mOutput.writeChar(v);
    }

    /**
     * Writes an <code>int</code> to the underlying output stream as four
     * bytes, high byte first. If no exception is thrown, the counter 
     * <code>written</code> is incremented by <code>4</code>.
     *
     * @param      v   an <code>int</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeInt(int v) throws IOException {
        this.mOutput.writeInt(v);
    }

    /**
     * Writes a <code>long</code> to the underlying output stream as eight
     * bytes, high byte first. In no exception is thrown, the counter 
     * <code>written</code> is incremented by <code>8</code>.
     *
     * @param      v   a <code>long</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeLong(long v) throws IOException {
        this.mOutput.writeLong(v);
    }

    /**
     * Converts the float argument to an <code>int</code> using the 
     * <code>floatToIntBits</code> method in class <code>Float</code>, 
     * and then writes that <code>int</code> value to the underlying 
     * output stream as a 4-byte quantity, high byte first. If no 
     * exception is thrown, the counter <code>written</code> is 
     * incremented by <code>4</code>.
     *
     * @param      v   a <code>float</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     * @see        java.lang.Float#floatToIntBits(float)
     */
    public final void writeFloat(float v) throws IOException {
	this.mOutput.writeFloat(v);
    }

    /**
     * Converts the double argument to a <code>long</code> using the 
     * <code>doubleToLongBits</code> method in class <code>Double</code>, 
     * and then writes that <code>long</code> value to the underlying 
     * output stream as an 8-byte quantity, high byte first. If no 
     * exception is thrown, the counter <code>written</code> is 
     * incremented by <code>8</code>.
     *
     * @param      v   a <code>double</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     * @see        java.lang.Double#doubleToLongBits(double)
     */
    public final void writeDouble(double v) throws IOException {
	this.mOutput.writeDouble(v);
    }

    /**
     * Writes out the string to the underlying output stream as a 
     * sequence of bytes. Each character in the string is written out, in 
     * sequence, by discarding its high eight bits. If no exception is 
     * thrown, the counter <code>written</code> is incremented by the 
     * length of <code>s</code>.
     *
     * @param      s   a string of bytes to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeBytes(String s) throws IOException {
	this.mOutput.writeBytes(s);
    }

    /**
     * Writes a string to the underlying output stream as a sequence of 
     * characters. Each character is written to the data output stream as 
     * if by the <code>writeChar</code> method. If no exception is 
     * thrown, the counter <code>written</code> is incremented by twice 
     * the length of <code>s</code>.
     *
     * @param      s   a <code>String</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.DataOutputStream#writeChar(int)
     * @see        java.io.FilterOutputStream#out
     */
    public final void writeChars(String s) throws IOException {
        this.mOutput.writeChars(s);
    }

    /**
     * Writes a string to the underlying output stream using
     * <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
     * encoding in a machine-independent manner. 
     * <p>
     * First, two bytes are written to the output stream as if by the 
     * <code>writeShort</code> method giving the number of bytes to 
     * follow. This value is the number of bytes actually written out, 
     * not the length of the string. Following the length, each character 
     * of the string is output, in sequence, using the modified UTF-8 encoding
     * for the character. If no exception is thrown, the counter 
     * <code>written</code> is incremented by the total number of 
     * bytes written to the output stream. This will be at least two 
     * plus the length of <code>str</code>, and at most two plus 
     * thrice the length of <code>str</code>.
     *
     * @param      str   a string to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeUTF(String str) throws IOException {
        this.mOutput.writeUTF(str);
    }

    /**
     * Returns the current value of the counter <code>written</code>, 
     * the number of bytes written to this data output stream so far.
     * If the counter overflows, it will be wrapped to Integer.MAX_VALUE.
     *
     * @return  the value of the <code>written</code> field.
     * @see     java.io.DataOutputStream#written
     */
    public final int size() {
	return this.mOutput.size();
    }

    /**
     * Write the specified object to the ObjectOutputStream. Objects referenced by this
     * object are written transitively so that a complete equivalent graph of
     * objects can be reconstructed by an ObjectInputStream.
     *
     * <p>Exceptions are thrown for problems with the OutputStream and for
     * classes that should not be serialized.  All exceptions are fatal to the
     * OutputStream, which is left in an indeterminate state, and it is up to
     * the caller to ignore or recover the stream state.
     *
     * @throws	IOException Any exception thrown by the underlying
     * 		OutputStream.
     */
    public final void writeObject(Object obj) 
        throws IOException 
    {
        try 
        {
            // Find an appropriate surrogate for the object
            NxSerializationSurrogate surrogate = 
                    this.mSelector.getSurrogateForObject(obj);
            // write type handle
            surrogate.writeHandle(this, obj);
            surrogate.writeObject(this, obj);
        } 
        catch (Exception ex) 
        {
            throw new IOException(ex);
        }
    }

    /**
     * Write the specified object to the ObjectOutputStream. Objects referenced by this
     * object are written transitively so that a complete equivalent graph of
     * objects can be reconstructed by an ObjectInputStream.
     *
     * <p>Exceptions are thrown for problems with the OutputStream and for
     * classes that should not be serialized.  All exceptions are fatal to the
     * OutputStream, which is left in an indeterminate state, and it is up to
     * the caller to ignore or recover the stream state.
     *
     * @param obj the object to be written
     * @param objClass the class surrogate to use for writing the object.
     * @exception IOException Any of the usual Input/Output related exceptions.
     * @throws	IOException Any exception thrown by the underlying
     * 		OutputStream.
     */
    public void writeObject(Object obj, Class objClass)
      throws IOException
    {
        if (obj == null)
            throw new NullPointerException("obj");
        if (objClass == null)
            throw new NullPointerException("objClass");

        try 
        {
            NxSerializationSurrogate surrogate = this.mSelector.getSurrogateForType(objClass);
               surrogate.writeObject(this, obj);
            }
        catch (Exception ex) 
        {
            throw new IOException(ex);
        }
    }
}