socket.java

gcc3.2.1源代码

   */
  public int getLocalPort ()
  {
    if (impl != null)
      return impl.getLocalPort();

    return -1;
  }

  /**
   * Returns an InputStream for reading from this socket.
   *
   * @return The InputStream object
   *
   * @exception IOException If an error occurs or Socket is not connected
   */
  public InputStream getInputStream () throws IOException
  {
    if (impl != null)
      return(impl.getInputStream());

    throw new IOException("Not connected");
  }

  /**
   * Returns an OutputStream for writing to this socket.
   *
   * @return The OutputStream object
   *
   * @exception IOException If an error occurs or Socket is not connected
   */
  public OutputStream getOutputStream () throws IOException
  {
    if (impl != null)
      return impl.getOutputStream();

    throw new IOException("Not connected");
  }

  /**
   * Sets the TCP_NODELAY option on the socket. 
   *
   * @param on true to enable, false to disable
   * 
   * @exception SocketException If an error occurs or Socket is not connected
   */
  public void setTcpNoDelay (boolean on)  throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    impl.setOption(SocketOptions.TCP_NODELAY, new Boolean(on));
  }

  /**
   * Tests whether or not the TCP_NODELAY option is set on the socket. 
   * Returns true if enabled, false if disabled. When on it disables the
   * Nagle algorithm which means that packets are always send immediatly and
   * never merged together to reduce network trafic.
   *
   * @return Whether or not TCP_NODELAY is set
   * 
   * @exception SocketException If an error occurs or Socket not connected
   */
  public boolean getTcpNoDelay() throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    Object on = impl.getOption(SocketOptions.TCP_NODELAY);
  
    if (on instanceof Boolean)
      return(((Boolean)on).booleanValue());
    else
      throw new SocketException("Internal Error");
  }

  /**
   * Sets the value of the SO_LINGER option on the socket.  If the 
   * SO_LINGER option is set on a socket and there is still data waiting to
   * be sent when the socket is closed, then the close operation will block
   * until either that data is delivered or until the timeout period
   * expires.  The linger interval is specified in hundreths of a second
   * (platform specific?)
   *
   * @param on true to enable SO_LINGER, false to disable
   * @param linger The SO_LINGER timeout in hundreths of a second or -1 if 
   * SO_LINGER not set.
   *
   * @exception SocketException If an error occurs or Socket not connected
   */
  public void setSoLinger(boolean on, int linger) throws SocketException
  {
    if (impl == null)
      throw new SocketException("No socket created");

    if (on == true)
      {
        if (linger < 0)
          throw new IllegalArgumentException("SO_LINGER must be >= 0");

        if (linger > 65535)
          linger = 65535;

        impl.setOption(SocketOptions.SO_LINGER, new Integer(linger));
      }
    else
      {
        impl.setOption(SocketOptions.SO_LINGER, new Boolean(false));
      }
  }

  /**
   * Returns the value of the SO_LINGER option on the socket.  If the 
   * SO_LINGER option is set on a socket and there is still data waiting to
   * be sent when the socket is closed, then the close operation will block
   * until either that data is delivered or until the timeout period
   * expires.  This method either returns the timeouts (in hundredths of
   * of a second (platform specific?)) if SO_LINGER is set, or -1 if
   * SO_LINGER is not set.
   *
   * @return The SO_LINGER timeout in hundreths of a second or -1 
   * if SO_LINGER not set
   *
   * @exception SocketException If an error occurs or Socket is not connected
   */
  public int getSoLinger() throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    Object linger = impl.getOption(SocketOptions.SO_LINGER);
    if (linger instanceof Integer)
      return(((Integer)linger).intValue());
    else
      return -1;
  }

  /**
   * Sets the value of the SO_TIMEOUT option on the socket.  If this value
   * is set, and an read/write is performed that does not complete within
   * the timeout period, a short count is returned (or an EWOULDBLOCK signal
   * would be sent in Unix if no data had been read).  A value of 0 for
   * this option implies that there is no timeout (ie, operations will 
   * block forever).  On systems that have separate read and write timeout
   * values, this method returns the read timeout.  This
   * value is in thousandths of a second (****????*****)
   *
   * @param timeout The length of the timeout in thousandth's of a second or 
   * 0 if not set
   *
   * @exception SocketException If an error occurs or Socket not connected
   */
  public synchronized void setSoTimeout (int timeout) throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");
    
    if (timeout < 0)
      throw new IllegalArgumentException("SO_TIMEOUT value must be >= 0");
      
    impl.setOption(SocketOptions.SO_TIMEOUT, new Integer(timeout));
  }

  /**
   * Returns the value of the SO_TIMEOUT option on the socket.  If this value
   * is set, and an read/write is performed that does not complete within
   * the timeout period, a short count is returned (or an EWOULDBLOCK signal
   * would be sent in Unix if no data had been read).  A value of 0 for
   * this option implies that there is no timeout (ie, operations will 
   * block forever).  On systems that have separate read and write timeout
   * values, this method returns the read timeout.  This
   * value is in thousandths of a second (implementation specific?).
   *
   * @return The length of the timeout in thousandth's of a second or 0 
   * if not set
   *
   * @exception SocketException If an error occurs or Socket not connected
   */
  public synchronized int getSoTimeout () throws SocketException
  {
    if (impl == null) 
      throw new SocketException("Not connected");

    Object timeout = impl.getOption(SocketOptions.SO_TIMEOUT);
    if (timeout instanceof Integer)
      return(((Integer)timeout).intValue());
    else
      return 0;
  }

  /**
   * This method sets the value for the system level socket option
   * SO_SNDBUF to the specified value.  Note that valid values for this
   * option are specific to a given operating system.
   *
   * @param size The new send buffer size.
   *
   * @exception SocketException If an error occurs or Socket not connected
   *
   * @since Java 1.2
   */
  public void setSendBufferSize (int size) throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");
    
    if (size <= 0)
      throw new IllegalArgumentException("SO_SNDBUF value must be > 0");
    
    impl.setOption(SocketOptions.SO_SNDBUF, new Integer(size));
  }

  /**
   * This method returns the value of the system level socket option
   * SO_SNDBUF, which is used by the operating system to tune buffer
   * sizes for data transfers.
   *
   * @return The send buffer size.
   *
   * @exception SocketException If an error occurs or socket not connected
   *
   * @since Java 1.2
   */
  public int getSendBufferSize () throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    Object buf = impl.getOption(SocketOptions.SO_SNDBUF);

    if (buf instanceof Integer)
      return(((Integer)buf).intValue());
    else
      throw new SocketException("Internal Error: Unexpected type");
  }

  /**
   * This method sets the value for the system level socket option
   * SO_RCVBUF to the specified value.  Note that valid values for this
   * option are specific to a given operating system.
   *
   * @param size The new receive buffer size.
   *
   * @exception SocketException If an error occurs or Socket is not connected
   *
   * @since Java 1.2
   */
  public void setReceiveBufferSize (int size) throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    if (size <= 0)
      throw new IllegalArgumentException("SO_RCVBUF value must be > 0");
      
    impl.setOption(SocketOptions.SO_RCVBUF, new Integer(size));
  }

  /**
   * This method returns the value of the system level socket option
   * SO_RCVBUF, which is used by the operating system to tune buffer
   * sizes for data transfers.
   *
   * @return The receive buffer size.
   *
   * @exception SocketException If an error occurs or Socket is not connected
   *
   * @since Java 1.2
   */
  public int getReceiveBufferSize () throws SocketException
  {
    if (impl == null)
      throw new SocketException("Not connected");

    Object buf = impl.getOption(SocketOptions.SO_RCVBUF);

    if (buf instanceof Integer)
      return(((Integer)buf).intValue());
    else
      throw new SocketException("Internal Error: Unexpected type");
  }

  /**
   * Closes the socket.
   *
   * @exception IOException If an error occurs
   */
  public synchronized void close ()  throws IOException
  {
    if (impl != null)
      impl.close();
  }

  /**
   * Converts this <code>Socket</code> to a <code>String</code>.
   *
   * @return The <code>String</code> representation of this <code>Socket</code>
   */
  public String toString ()
  {
    return("Socket " + impl);
  }

  // Class Methods

  /**
   * Sets the <code>SocketImplFactory</code>.  This may be done only once per 
   * virtual machine.  Subsequent attempts will generate a 
   * <code>SocketException</code>.  Note that a <code>SecurityManager</code>
   * check is made prior to setting the factory.  If 
   * insufficient privileges exist to set the factory, then an 
   * <code>IOException</code> will be thrown.
   *
   * @exception SecurityException If the <code>SecurityManager</code> does
   * not allow this operation.
   * @exception SocketException If the SocketImplFactory is already defined
   * @exception IOException If any other error occurs
   */
  public static synchronized void setSocketImplFactory (SocketImplFactory fac)
    throws IOException
  {
    // See if already set
    if (factory != null)
      throw new SocketException("SocketImplFactory already defined");

    // Check permissions
    SecurityManager sm = System.getSecurityManager();
    if (sm != null)
      sm.checkSetFactory();

    factory = fac;
  }
}