package support.gui;
import jdsl.core.api.*;
import jdsl.core.ref.*;
import jdsl.graph.algo.*;
import jdsl.graph.api.*;
import jdsl.graph.ref.*;
import java.io.*;
import support.*;
import java.net.URL;
/**
* Helper class that has static functions that can parse data sets
* into flights graph, and manupulate it otherwise.
*
* @version JDSL 2
*/
public class Parser {
private static final int TT_WORD = StreamTokenizer.TT_WORD;
private static final int TT_NUMBER = StreamTokenizer.TT_NUMBER;
/**
* Removes all edges from a graph.
*
* @param <code>g</code> A graph
*/
static public void removeAllEdges(Graph g) {
for(EdgeIterator pi = g.edges(); pi.hasNext();) {
g.removeEdge((Edge)pi.nextEdge());
}
}
/**
* Removes all vertices from a graph.
*
* @param <code>g</code> A graph
*/
static public void removeAllVertices(Graph g) {
for(VertexIterator vi = g.vertices(); vi.hasNext(); ) {
g.removeVertex((Vertex)vi.nextVertex());
}
}
static public void parseGraph(String vFile, String eFile, Graph g)
throws FileNotFoundException, FlightException {
Dictionary airportToVertex = Parser.parseVertices(vFile, g);
Parser.parseEdges(eFile, g, airportToVertex);
}
static public void parseGraph(URL vURL, URL eURL, Graph g)
throws FileNotFoundException, FlightException {
Dictionary airportToVertex = Parser.parseVertices(vURL, g);
Parser.parseEdges(eURL, g, airportToVertex);
}
/**
* Parses vertices from a file into a graph.
*
* @param <code>filename</code> Name of the source file
* @param <code>g</code> A graph
*
* @return <code>Dictionary</code> mapping airport codes to vertices
*/
static public Dictionary parseVertices(String filename, Graph g)
throws FileNotFoundException, FlightException {
Reader reader = new BufferedReader(new FileReader(filename));
return Parser.parseVertices(reader, g);
}
/**
* Parses vertices from a URL into a graph.
*
* @param <code>url</code> Source URL
* @param <code>g</code> A graph
*
* @return <code>Dictionary</code> mapping airport codes to vertices
*/
static public Dictionary parseVertices(URL url, Graph g)
throws FileNotFoundException, FlightException {
InputStream is = null;
try {
is = url.openStream();
} catch(IOException e) {
throw new FlightException("IO Error: cannot read from URL " + url.toString());
}
Reader reader = new BufferedReader(new InputStreamReader(is));
return Parser.parseVertices(reader, g);
}
/**
* Parses vertices into a graph.
*
* @param <code>reader</code> Source reader
* @param <code>g</code> A graph
*
* @return <code>Dictionary</code> mapping airport codes to vertices
*/
static public Dictionary parseVertices(Reader reader, Graph g)
throws FileNotFoundException, FlightException {
StreamTokenizer toker = new AirportTokenizer(reader);
HashComparator comp = new jdsl.core.ref.ObjectHashComparator();
Dictionary airportToVertex = new jdsl.core.ref.HashtableDictionary(comp);
AirportSpecs spec;
try {
skipLeadingNewlines(toker);
while(toker.ttype != toker.TT_EOF) {
spec = Parser.parseAirport(toker);
airportToVertex.insert(spec.code(), g.insertVertex(spec));
skipLeadingNewlines(toker);
}
}
catch(IOException e) {
removeAllVertices(g);
throw new FlightException("IO Error at line " + toker.lineno() +
": " + e.getMessage());
}
return airportToVertex;
}
/**
* Parses edges from a URL into a graph.
*
* @param <code>url</code> A source URL
* @param <code>g</code> A graph
* @param <code>airportToVertex</code> Dictionary mapping airports to vertices
*/
static public void parseEdges(URL url, Graph g, Dictionary airportToVertex)
throws FileNotFoundException, FlightException {
InputStream is = null;
try {
is = url.openStream();
} catch(IOException e) {
throw new FlightException("IO Error: cannot read from URL " + url.toString());
}
Reader reader = new BufferedReader(new InputStreamReader(is));
Parser.parseEdges(reader, g, airportToVertex);
}
/**
* Parses edges from a file into a graph.
*
* @param <code>filename</code> Source filename
* @param <code>g</code> A graph
* @param <code>airportToVertex</code> Dictionary mapping airports to vertices
*/
static public void parseEdges(String filename, Graph g, Dictionary airportToVertex)
throws FileNotFoundException, FlightException {
Reader reader = new BufferedReader(new FileReader(filename));
parseEdges(reader, g, airportToVertex);
}
/**
* Parses edges into a graph.
*
* @param <code>reader</code> Source reader
* @param <code>g</code> A graph
* @param <code>airportToVertex</code> Dictionary mapping airports to vertices
*/
static public void parseEdges(Reader reader, Graph g, Dictionary airportToVertex)
throws FileNotFoundException, FlightException {
StreamTokenizer toker = new FlightTokenizer(reader);
FlightSpecs spec;
Vertex from, to;
try {
skipLeadingNewlines(toker);
while(toker.ttype != toker.TT_EOF) {
spec = Parser.parseFlight(toker, airportToVertex);
from = (Vertex)(airportToVertex.find(spec.originCode()).element());
to = (Vertex)(airportToVertex.find(spec.destinationCode()).element());
if (from == null || to == null) {
throw new FlightException("Error at line " + toker.lineno() + ": " +
"airport " + spec.originCode() + " or " +
spec.destinationCode() + " does not exist.");
}
g.insertDirectedEdge(from, to, spec);
Parser.skipLeadingNewlines(toker);
}
}
catch(IOException e) {
throw new FlightException("IO Error at line " + toker.lineno() +
": " + e.getMessage());
}
}
static public void skipLeadingNewlines(StreamTokenizer t)
throws IOException {
while(t.nextToken() == t.TT_EOL);
t.pushBack();
}
static public AirportSpecs parseAirport(StreamTokenizer toker)
throws FlightException, IOException {
String code, city;
int gmtOffset, x, y;
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Did not find airport code at "
+ toker.lineno());
if(toker.sval.length() != 3)
throw new FlightException("Airport code should be 3 letters; Found: "
+ toker.sval + " at line " +
toker.lineno());
code = toker.sval;
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Did not find GMT offset at line "
+ toker.lineno());
gmtOffset = (int)toker.nval;
// now convert gmtOffset to minutes from GMT;
// hours is the current / 100,
// minutes is the current % 100
gmtOffset = (gmtOffset / 100) * 60 + (gmtOffset % 100);
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Did not find airport's x-coordinate at line "
+ toker.lineno());
x = (int)toker.nval;
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Did not find airport's y-coordinate at line "
+ toker.lineno());
y = (int)toker.nval;
city = "";
while(toker.nextToken() != toker.TT_EOL) {
city = city + " " + toker.sval;
}
return new AirportSpecs(code, city, gmtOffset, x, y);
} // parseAirport
static public FlightSpecs parseFlight(StreamTokenizer toker, Dictionary airportToVertex)
throws IOException, FlightException {
String airline, orig, dest, plane, fares;
int flightnum, timeint, depTime, arrTime, gdepTime, garrTime;
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Expected flight code at " +
toker.lineno());
if(toker.sval.length() > 2) {
try {
airline = toker.sval.substring(0, 2);
flightnum = Integer.parseInt(toker.sval.substring(2));
}
catch(NumberFormatException e) {
throw new FlightException("'" + toker.sval.substring(2) +
"' is not an integer at line " +
toker.lineno());
}
} else {
airline = toker.sval;
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Expected an integer flight number at line" +
toker.lineno());
flightnum = (int)toker.nval;
}
// Parse departure info
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Expected airport code at line " +
toker.lineno());
if(toker.sval.length() != 3)
throw new FlightException("Airport code should be 3 letters; Found: "
+ toker.sval + " at line " +
toker.lineno());
orig = toker.sval;
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Expected departure time at line " +
toker.lineno());
timeint = (int)toker.nval;
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Expected meridian on departure time at line " +
toker.lineno());
try {
depTime = StandardOps.parseTime(timeint + toker.sval);
}
catch(IllegalArgumentException i) {
throw new FlightException(i.getMessage() + " at line " +
toker.lineno());
}
gdepTime = StandardOps.toGMT
(depTime,
((AirportSpecs)(((Vertex)airportToVertex.find(orig).element()).element())).GMToffset());
// Parse arrival info
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Expected airport code at line " +
toker.lineno());
if(toker.sval.length() != 3)
throw new FlightException("Airport code should be 3 letters; Found: "
+ toker.sval + " at line " +
toker.lineno());
dest = toker.sval;
if(toker.nextToken() != toker.TT_NUMBER)
throw new FlightException("Expected arrival time at line " +
toker.lineno());
timeint = (int)toker.nval;
if(toker.nextToken() != toker.TT_WORD)
throw new FlightException("Expected meridian on arrival time at line " +
toker.lineno());
try {
arrTime = StandardOps.parseTime(timeint + toker.sval);
}
catch(IllegalArgumentException i) {
throw new FlightException(i.getMessage() + " at line " +
toker.lineno());
}
garrTime = StandardOps.toGMT
(arrTime,
((AirportSpecs)(((Vertex)airportToVertex.find(dest).element()).element())).GMToffset());
switch(toker.nextToken()) {
case TT_WORD:
plane = toker.sval;
if(toker.nextToken() == toker.TT_NUMBER)
plane = plane + (int)toker.nval;
else toker.pushBack();
break;
case TT_NUMBER:
plane = "" + (int)toker.nval;
break;
default:
throw new FlightException("Expected airplane model type at line " +
toker.lineno());
}
fares = "";
while(toker.nextToken() == toker.TT_WORD) {
//System.out.println(toker.sval);
fares = fares + " " + toker.sval;
}
if(toker.ttype != toker.TT_NUMBER)
throw new FlightException("Expected cargo capacity at line " +
toker.lineno());
int cargo = (int)toker.nval;
if(toker.nextToken() != toker.TT_EOL)
throw new FlightException("Expected end of line at line " +
toker.lineno());
return new FlightSpecs(airline, flightnum, orig, dest,
depTime, arrTime, gdepTime, garrTime,
plane, fares, cargo);
}
}