org.jgrapht.io.GmlExporter Maven / Gradle / Ivy
/*
* (C) Copyright 2006-2017, by Dimitrios Michail and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* 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.
*/
package org.jgrapht.io;
import org.apache.commons.lang3.*;
import org.jgrapht.*;
import java.io.*;
import java.util.*;
/**
* Exports a graph into a GML file (Graph Modeling Language).
*
*
* For a description of the format see
* http://www. infosun.fmi.uni-passau.de/Graphlet/GML/.
*
*
* The behavior of the exporter such as whether to print vertex labels, edge labels, and/or edge
* weights can be adjusted using the {@link #setParameter(Parameter, boolean) setParameter} method.
* When exporting labels, the exporter escapes them as Java strings.
*
* @param the graph vertex type
* @param the graph edge type
*
* @author Dimitrios Michail
*/
public class GmlExporter
extends
AbstractBaseExporter
implements
GraphExporter
{
private static final String CREATOR = "JGraphT GML Exporter";
private static final String VERSION = "1";
private static final String DELIM = " ";
private static final String TAB1 = "\t";
private static final String TAB2 = "\t\t";
private ComponentNameProvider vertexLabelProvider;
private ComponentNameProvider edgeLabelProvider;
private final Set parameters;
/**
* Parameters that affect the behavior of the {@link GmlExporter} exporter.
*/
public enum Parameter
{
/**
* If set the exporter outputs edge labels
*/
EXPORT_EDGE_LABELS,
/**
* If set the exporter outputs vertex labels
*/
EXPORT_VERTEX_LABELS,
/**
* If set the exporter outputs edge weights
*/
EXPORT_EDGE_WEIGHTS,
/**
* If set the exporter escapes all strings as Java strings, otherwise no escaping is
* performed.
*/
ESCAPE_STRINGS_AS_JAVA,
}
/**
* Creates a new GmlExporter object with integer name providers for the vertex and edge IDs and
* null providers for the vertex and edge labels.
*/
public GmlExporter()
{
this(
new IntegerComponentNameProvider<>(), null, new IntegerComponentNameProvider<>(), null);
}
/**
* Constructs a new GmlExporter object with the given ID and label providers.
*
* @param vertexIDProvider for generating vertex IDs. Must not be null.
* @param vertexLabelProvider for generating vertex labels. If null, vertex labels will be
* generated using the toString() method of the vertex object.
* @param edgeIDProvider for generating vertex IDs. Must not be null.
* @param edgeLabelProvider for generating edge labels. If null, edge labels will be generated
* using the toString() method of the edge object.
*/
public GmlExporter(
ComponentNameProvider vertexIDProvider, ComponentNameProvider vertexLabelProvider,
ComponentNameProvider edgeIDProvider, ComponentNameProvider edgeLabelProvider)
{
super(
vertexIDProvider,
Objects.requireNonNull(edgeIDProvider, "Edge ID provider cannot be null"));
this.vertexLabelProvider = vertexLabelProvider;
this.edgeLabelProvider = edgeLabelProvider;
this.parameters = new HashSet<>();
}
private String quoted(final String s)
{
boolean escapeStringAsJava = parameters.contains(Parameter.ESCAPE_STRINGS_AS_JAVA);
if (escapeStringAsJava) {
return "\"" + StringEscapeUtils.escapeJava(s) + "\"";
} else {
return "\"" + s + "\"";
}
}
private void exportHeader(PrintWriter out)
{
out.println("Creator" + DELIM + quoted(CREATOR));
out.println("Version" + DELIM + VERSION);
}
private void exportVertices(PrintWriter out, Graph g)
{
boolean exportVertexLabels = parameters.contains(Parameter.EXPORT_VERTEX_LABELS);
for (V from : g.vertexSet()) {
out.println(TAB1 + "node");
out.println(TAB1 + "[");
out.println(TAB2 + "id" + DELIM + vertexIDProvider.getName(from));
if (exportVertexLabels) {
String label = (vertexLabelProvider == null) ? from.toString()
: vertexLabelProvider.getName(from);
out.println(TAB2 + "label" + DELIM + quoted(label));
}
out.println(TAB1 + "]");
}
}
private void exportEdges(PrintWriter out, Graph g)
{
boolean exportEdgeWeights = parameters.contains(Parameter.EXPORT_EDGE_WEIGHTS);
boolean exportEdgeLabels = parameters.contains(Parameter.EXPORT_EDGE_LABELS);
for (E edge : g.edgeSet()) {
out.println(TAB1 + "edge");
out.println(TAB1 + "[");
String id = edgeIDProvider.getName(edge);
out.println(TAB2 + "id" + DELIM + id);
String s = vertexIDProvider.getName(g.getEdgeSource(edge));
out.println(TAB2 + "source" + DELIM + s);
String t = vertexIDProvider.getName(g.getEdgeTarget(edge));
out.println(TAB2 + "target" + DELIM + t);
if (exportEdgeLabels) {
String label =
(edgeLabelProvider == null) ? edge.toString() : edgeLabelProvider.getName(edge);
out.println(TAB2 + "label" + DELIM + quoted(label));
}
if (exportEdgeWeights && g.getType().isWeighted()) {
out.println(TAB2 + "weight" + DELIM + Double.toString(g.getEdgeWeight(edge)));
}
out.println(TAB1 + "]");
}
}
/**
* Exports an graph into a plain text GML format.
*
* @param writer the writer
* @param g the graph
*/
@Override
public void exportGraph(Graph g, Writer writer)
{
PrintWriter out = new PrintWriter(writer);
for (V from : g.vertexSet()) {
// assign ids in vertex set iteration order
vertexIDProvider.getName(from);
}
exportHeader(out);
out.println("graph");
out.println("[");
out.println(TAB1 + "label" + DELIM + quoted(""));
if (g.getType().isDirected()) {
out.println(TAB1 + "directed" + DELIM + "1");
} else {
out.println(TAB1 + "directed" + DELIM + "0");
}
exportVertices(out, g);
exportEdges(out, g);
out.println("]");
out.flush();
}
/**
* Return if a particular parameter of the exporter is enabled
*
* @param p the parameter
* @return {@code true} if the parameter is set, {@code false} otherwise
*/
public boolean isParameter(Parameter p)
{
return parameters.contains(p);
}
/**
* Set the value of a parameter of the exporter
*
* @param p the parameter
* @param value the value to set
*/
public void setParameter(Parameter p, boolean value)
{
if (value) {
parameters.add(p);
} else {
parameters.remove(p);
}
}
}
// End GmlExporter.java