org.acplt.oncrpc.OncRpcUdpSocketHelper Maven / Gradle / Ivy
/*
* $Header: /cvsroot/remotetea/remotetea/src/org/acplt/oncrpc/OncRpcUdpSocketHelper.java,v 1.3 2007/05/29 19:45:46 haraldalbrecht Exp $
*
* Copyright (c) 2001
* Lehrstuhl fuer Prozessleittechnik (PLT), RWTH Aachen
* D-52064 Aachen, Germany.
* All rights reserved.
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This library 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program (see the file COPYING.LIB for more
* details); if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.acplt.oncrpc;
import java.net.*;
import java.lang.reflect.*;
/**
* Wraps JRE-specific networking code for UDP/IP-based client sockets.
* So much for compile once, make it unuseable everywhere.
*
* The following JRE-dependent methods are wrapped and will just do
* nothing or return fake information on old JRE plattforms. The number
* after each method wrapper indicates the first JRE version supporting
* a particular feature:
*
* setSendBufferSize() -- 1.2
* setReceiveBufferSize() -- 1.2
*
*
* The following methods have been around since JDK 1.1, so we
* do not need to wrap them as we will never support JDK 1.0 -- let
* it rest in piece(s):
*
* - getTcpNoDelay() / setTcpNoDelay()
*
- getSoTimeout() / setSoTimeout()
*
*
* @version $Header: /cvsroot/remotetea/remotetea/src/org/acplt/oncrpc/OncRpcUdpSocketHelper.java,v 1.3 2007/05/29 19:45:46 haraldalbrecht Exp $
* @author Harald Albrecht
*/
public class OncRpcUdpSocketHelper {
/**
* Creates a datagram socket and binds it to an arbitrary available port
* on the local host machine.
*/
public OncRpcUdpSocketHelper(DatagramSocket socket) {
this.socket = socket;
queryMethods();
}
/**
* Sets the socket's send buffer size as a hint to the underlying
* transport layer to use appropriately sized I/O buffers. If the class
* libraries of the underlying JRE do not support setting the send
* buffer size, this is silently ignored.
*
* @param size The size to which to set the send buffer size. This value
* must be greater than 0.
*
* @throws SocketException if the socket's send buffer size could not
* be set, because the transport layer decided against accepting the
* new buffer size.
* @throws IllegalArgumentException if size is 0 or negative.
*/
public void setSendBufferSize(int size)
throws SocketException {
if ( methodSetSendBufferSize != null ) {
try {
methodSetSendBufferSize.invoke(socket, new Object [] {
new Integer(size)
});
} catch ( InvocationTargetException e ) {
Throwable t = e.getTargetException();
if ( t instanceof SocketException ) {
throw((SocketException) t);
} else if ( t instanceof IllegalArgumentException ) {
throw((IllegalArgumentException) t);
}
throw(new SocketException(t.getMessage()));
} catch ( IllegalAccessException e ) {
throw(new SocketException(e.getMessage()));
}
}
}
/**
* Get size of send buffer for this socket.
*
* @return Size of send buffer.
*
* @throws SocketException If the transport layer could not be queried
* for the size of this socket's send buffer.
*/
public int getSendBufferSize()
throws SocketException {
if ( methodGetSendBufferSize != null ) {
try {
Object result = methodGetSendBufferSize.invoke(socket, (Object[]) null);
if ( result instanceof Integer ) {
return ((Integer) result).intValue();
}
} catch ( InvocationTargetException e ) {
Throwable t = e.getTargetException();
if ( t instanceof SocketException ) {
throw((SocketException) t);
}
throw(new SocketException(t.getMessage()));
} catch ( IllegalAccessException e ) {
throw(new SocketException(e.getMessage()));
}
}
//
// Without knowing better we can only return fake information.
// For quite some solaris OS revisions, the buffer size returned
// is beyond their typical configuration, with only 8k for fragment
// reassemble set asside by the IP layer. What a NOS...
//
return 65536;
}
/**
* Sets the socket's receive buffer size as a hint to the underlying
* transport layer to use appropriately sized I/O buffers. If the class
* libraries of the underlying JRE do not support setting the receive
* buffer size, this is silently ignored.
*
* @param size The size to which to set the receive buffer size. This value
* must be greater than 0.
*
* @throws SocketException if the socket's receive buffer size could not
* be set, because the transport layer decided against accepting the
* new buffer size.
* @throws IllegalArgumentException if size is 0 or negative.
*/
public void setReceiveBufferSize(int size)
throws SocketException {
if ( methodSetReceiveBufferSize != null ) {
try {
methodSetReceiveBufferSize.invoke(socket, new Object [] {
new Integer(size)
});
} catch ( InvocationTargetException e ) {
Throwable t = e.getTargetException();
if ( t instanceof SocketException ) {
throw((SocketException) t);
} else if ( t instanceof IllegalArgumentException ) {
throw((IllegalArgumentException) t);
}
} catch ( IllegalAccessException e ) {
throw(new SocketException(e.getMessage()));
}
}
}
/**
* Get size of receive buffer for this socket.
*
* @return Size of receive buffer.
*
* @throws SocketException If the transport layer could not be queried
* for the size of this socket's receive buffer.
*/
public int getReceiveBufferSize()
throws SocketException {
if ( methodGetReceiveBufferSize != null ) {
try {
Object result = methodGetReceiveBufferSize.invoke(socket, (Object[]) null);
if ( result instanceof Integer ) {
return ((Integer) result).intValue();
}
} catch ( InvocationTargetException e ) {
Throwable t = e.getTargetException();
if ( t instanceof SocketException ) {
throw((SocketException) t);
}
throw(new SocketException(t.getMessage()));
} catch ( IllegalAccessException e ) {
throw(new SocketException(e.getMessage()));
}
}
//
// Without knowing better we can only return fake information.
// For quite some solaris OS revisions, the buffer size returned
// is beyond their typical configuration, with only 8k for fragment
// reassemble set asside by the IP layer. What a NOS...
//
return 65536;
}
/**
* Looks up methods of class DatagramSocket whether they are supported
* by the class libraries of the JRE we are currently executing on.
*/
protected void queryMethods() {
Class c = DatagramSocket.class;
try {
methodSetSendBufferSize = c.getMethod("setSendBufferSize",
new Class [] {int.class});
methodGetSendBufferSize = c.getMethod("getSendBufferSize", (Class[]) null);
} catch ( Exception e ) { }
try {
methodSetReceiveBufferSize = c.getMethod("setReceiveBufferSize",
new Class [] {int.class});
methodGetReceiveBufferSize = c.getMethod("getReceiveBufferSize", (Class[]) null);
} catch ( Exception e ) { }
}
/**
* The datagram socket for which we have to help out with some missing
* methods.
*/
private DatagramSocket socket;
/**
* Method Socket.setSendBufferSize or null if not available
* in the class library of a particular JRE.
*/
private Method methodSetSendBufferSize;
/**
* Method Socket.setReceiverBufferSize or null if not available
* in the class library of a particular JRE.
*/
private Method methodSetReceiveBufferSize;
/**
* Method Socket.getSendBufferSize or null if not available
* in the class library of a particular JRE.
*/
private Method methodGetSendBufferSize;
/**
* Method Socket.getReceiveBufferSize or null if not available
* in the class library of a particular JRE.
*/
private Method methodGetReceiveBufferSize;
}
// End of OncRpcUdpSocketHelper.java