/*
* MbPacket.java
*
* Created on den 24 augusti 2003, 12:55
*/
package Macbeth.System;
import Macbeth.XML.XMLDataHandler;
import Macbeth.XML.XMLParser;
import Macbeth.Utilities.MySystem;
import java.util.Iterator;
import java.util.HashMap;
import java.io.IOException;
import org.xml.sax.SAXException;
/**
* This class represents a Macbeth packet, containing both its destination,
* its source, and its contents.
* @author Jimmy
*/
public class MbPacket {
/**
* The Macbeth location to which this packet is addressed.
* If the kernel-field is set to "self", it means that
* the packet will be delivered locally only (that is,
* within the same kernel it was sent from). If the field
* is set to something else, however, this name will be
* looked up in the list of known kernels, which, in case
* the kernel was found, also provides the internet address
* of the specified kernel.
*/
private MbLocation destination;
/**
* The Macbeth location from which this packet was sent.
* This can be used by receiver module (or kernel)
* to identify the sender.
*/
private MbLocation source;
/**
* The packet contents (an XML-document).
*/
/**
* The remote address of the client that sent us this packet.
* If the packet has never been transported via any networks,
* this value is "self" (that is, source kernel and dest kernel
* are equal).
*/
/**
* Gets the destination of this packet.
* @return The packet destination.
*/
public MbLocation getDestination() {
return destination;
}
/**
* Sets the destination of this packet.
* @param destination The new destination.
*/
public void setDestination(MbLocation destination) {
this.destination = destination;
}
/**
* Sets the kernel field in the destination of this packet.
* @param kernel The new destination kernel.
*/
public void setDestinationKernel
(String kernel
) { destination.setKernel(kernel);
}
/**
* Sets the module field in the destination of this packet.
* @param module The new destination module.
*/
public void setDestinationModule
(String module
) { destination.setModule(module);
}
/**
* Gets the source of this packet.
* @return The packet source.
*/
public MbLocation getSource() {
return source;
}
/**
* Sets the source of this packet.
* @param source The new packet source.
*/
public void setSource(MbLocation source) {
this.source = source;
}
/**
* Gets the packet contents. This is an XML-string.
* @return The packet contents.
*/
public synchronized String getContents
() { return contents;
}
/**
* Sets the packet contents. This must be valid XML-data.
* @param contents The new packet contents.
*/
public synchronized void setContents
(String contents
) { this.contents = contents;
}
/**
* Appends a string to the packet contents. This must be
* valid XML-data.
* @param s The string to append.
*/
public synchronized void appendContents
(String s
) { this.contents += s;
}
/**
* Gets the source remote address of this packet.
* @return The remote address of the packet source.
*/
public synchronized String getOriginAddress
() { return originAddress;
}
/**
* Creates a new instance of MbPacket.
*/
public MbPacket() {
destination = new MbLocation();
source = new MbLocation();
originAddress = "self";
contents = "";
}
/**
* Serializes this packet into a string object (XML-formatted)
* @return the packet as an XML-string.
*/
public String serializeToString
() { s += "sourcekernel=\"" + source.getKernel() + "\" ";
s += "sourcemodule=\"" + source.getModule() + "\" ";
//s += "destkernel=\"" + destination.kernel + "\" ";
s += "destmodule=\"" + destination.getModule() + "\" ";
s += ">" + MySystem.lineBreak;
s += contents;
s += MySystem.lineBreak + "</mbpacket>";
return s;
}
/**
* Tries to deserialize an XML-string into a packet.
* The format of the string must be:
* <mbpacket destmodule="modulename">
* Only valid XML-data in here!
* </mbpacket>
* or else this function will not succeed.
* @param s The XML-string
* @return true if successful, false otherwise.
* @throws SAXException if the string contains an invalid XML document (syntax errors).
*/
//destination kernel is always set to "self"
destination = new MbLocation("self",null);
source = new MbLocation("external","external");
contents = "";
XMLParser xmlParser = new XMLParser(new DataHandler());
try {
xmlParser.parseString(s);
e.printStackTrace();
return false;
}
//TODO: why check this? can it happen?
if (destination==null) {
return false;
}
return true;
}
/**
* A data handler for XML parser.
*/
private class DataHandler implements XMLDataHandler {
//current element name
private String currentElement =
null; //current data for the element
private String currentElementData =
null;
public void XMLstartElement
(String element,
HashMap attributes
) { currentElementData = null;
if (element.equals("mbpacket")) {
if (attributes.containsKey("sourcekernel")) {
source.
setKernel((String)attributes.
get("sourcekernel")); }
if (attributes.containsKey("sourcemodule")) {
source.
setModule((String)attributes.
get("sourcemodule")); }
if (attributes.containsKey("destmodule")) {
destination.
setModule((String)attributes.
get("destmodule")); }
// NOTE: destination kernel is IGNORED in all incoming packets!
// (for security reasons, since no relaying is allowed. destkernel is always set to "self")
} else if (element.equals("remoteaddress") && originAddress.equals("self")) {
//(it must equal self, or else it can be set more than once, and can thus be faked)
//remember remote address
if (attributes.containsKey("value")) {
originAddress =
(String)attributes.
get("value"); }
} else {
//this is user data, so put it into the contents field
currentElement = element;
contents += "<" + element;
Iterator it = attributes.
keySet().
iterator(); while (it.hasNext()) {
contents += " " + key + "=\"" + attributes.get(key) + "\"";
}
//NEW CODE:
contents += ">";
}
}
public void XMLelementData
(String data
) { //NEW CODE
if (currentElement!=null) {
contents += MySystem.lineBreak + data;
currentElementData = data;
}
}
public void XMLendElement
(String element
) { if (!element.equals("remoteaddress") && !element.equals("mbpacket")) {
//NEW CODE:
//always add full end tag
//TODO: maybe fix this again. OLD CODE caused some ">" to be missing though!
contents += "</" + element + ">";
}
currentElement = null;
}
public void XMLdocumentStart() {}
public void XMLdocumentEnd() {}
}
}