org.jgrapht.experimental.GraphReader Maven / Gradle / Ivy
/* ==========================================
* JGraphT : a free Java graph-theory library
* ==========================================
*
* Project Info: http://jgrapht.sourceforge.net/
* Project Creator: Barak Naveh (http://sourceforge.net/users/barak_naveh)
*
* (C) Copyright 2003-2008, by Barak Naveh and Contributors.
*
* This program and the accompanying materials are dual-licensed under
* either
*
* (a) the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation, or (at your option) any
* later version.
*
* or (per the licensee's choosing)
*
* (b) the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation.
*/
/* -------------------
* GraphReader.java
* -------------------
* (C) Copyright 2003-2008, by Barak Naveh and Contributors.
*
* Original Author: Barak Naveh
* Contributor(s): -
*
* $Id$
*
* Changes
* -------
* 16-Sep-2003 : Initial revision (BN);
*
*/
package org.jgrapht.experimental;
import java.io.*;
import java.util.*;
import org.jgrapht.*;
import org.jgrapht.generate.*;
public class GraphReader
implements GraphGenerator
{
// ~ Static fields/initializers --------------------------------------------
// ~ Instance fields -------------------------------------------------------
// ~ Static fields/initializers --------------------------------------------
// ~ Instance fields -------------------------------------------------------
private final BufferedReader _in;
private final boolean _isWeighted;
private final double _defaultWeight;
// ~ Constructors ----------------------------------------------------------
/**
* Construct a new GraphReader.
*/
private GraphReader(Reader input, boolean isWeighted, double defaultWeight)
throws IOException
{
if (input instanceof BufferedReader) {
_in = (BufferedReader) input;
} else {
_in = new BufferedReader(input);
}
_isWeighted = isWeighted;
_defaultWeight = defaultWeight;
}
/**
* Construct a new GraphReader.
*/
public GraphReader(Reader input)
throws IOException
{
this(input, false, 1);
}
/**
* Construct a new GraphReader.
*/
public GraphReader(Reader input, double defaultWeight)
throws IOException
{
this(input, true, defaultWeight);
}
// ~ Methods ---------------------------------------------------------------
private String [] split(final String src)
{
if (src == null) {
return null;
}
return src.split("\\s+");
}
private String [] skipComments()
{
String [] cols = null;
try {
cols = split(_in.readLine());
while (
(cols != null)
&& ((cols.length == 0)
|| cols[0].equals("c")
|| cols[0].startsWith("%")))
{
cols = split(_in.readLine());
}
} catch (IOException e) {
}
return cols;
}
private int readNodeCount()
{
final String [] cols = skipComments();
if (cols[0].equals("p")) {
return Integer.parseInt(cols[1]);
}
return -1;
}
/**
* {@inheritDoc}
*/
public void generateGraph(
Graph target,
VertexFactory vertexFactory,
Map resultMap)
{
final int size = readNodeCount();
if (resultMap == null) {
resultMap = new HashMap();
}
for (int i = 0; i < size; i++) {
V newVertex = vertexFactory.createVertex();
target.addVertex(newVertex);
resultMap.put(Integer.toString(i + 1), newVertex);
}
String [] cols = skipComments();
while (cols != null) {
if (cols[0].equals("e")) {
E edge =
target.addEdge(
resultMap.get(cols[1]),
resultMap.get(cols[2]));
if (_isWeighted && (edge != null)) {
double weight = _defaultWeight;
if (cols.length > 3) {
weight = Double.parseDouble(cols[3]);
}
((WeightedGraph) target).setEdgeWeight(edge, weight);
}
}
cols = skipComments();
}
}
}
// End GraphReader.java