Class CSVImporter<V,E>

java.lang.Object

org.jgrapht.nio.BaseEventDrivenImporter<V,E>

org.jgrapht.nio.csv.CSVImporter<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

GraphImporter<V,E>

public class CSVImporter<V,E>
extends BaseEventDrivenImporter<V,E>
implements GraphImporter<V,E>

Imports a graph from a CSV Format or any other Delimiter-separated value format.

The importer supports various different formats which can be adjusted using the setFormat method. The supported formats are the same CSV formats used by Gephi . For some of the formats, the behavior of the importer can be adjusted using the setParameter method. See CSVFormat for a description of the formats.

The importer respects rfc4180. The caller can also adjust the separator to something like semicolon or pipe instead of comma. In such a case, all fields are unescaped using the new separator. See Delimiter- separated values for more information.

This importer does not distinguish between CSVFormat.EDGE_LIST and CSVFormat.ADJACENCY_LIST. In both cases it assumes the format is CSVFormat.ADJACENCY_LIST.

The graph vertices and edges are build using the corresponding graph suppliers. The id of the vertices in the original file are reported as a vertex attribute named "ID".

The default behavior of the importer is to use the graph vertex supplier in order to create vertices. The user can also bypass vertex creation by providing a custom vertex factory method using setVertexFactory(Function). The factory method is responsible to create a new graph vertex given the vertex identifier read from file.

See Also:

• CSVFormat

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	CSVImporter.Consumers

Field Summary

Fields

Modifier and Type	Field	Description
private static final char	DEFAULT_DELIMITER
private static final String	DEFAULT_VERTEX_ID_KEY
private static final String	DEFAULT_WEIGHT_KEY
private char	delimiter
private CSVFormat	format
private final Set<CSVFormat.Parameter>	parameters
private Function<String,V>	vertexFactory

Constructor Summary

Constructors

Constructor	Description
CSVImporter()	Constructs a new importer using the CSVFormat.ADJACENCY_LIST format as default.
CSVImporter(CSVFormat format)	Constructs a new importer.
CSVImporter(CSVFormat format, char delimiter)	Constructs a new importer.

Method Summary

Modifier and Type	Method	Description
char	getDelimiter()	Get the delimiter (comma, semicolon, pipe, etc).
CSVFormat	getFormat()	Get the format that the importer is using.
Function<String,V>	getVertexFactory()	Get the user custom vertex factory.
void	importGraph(Graph<V,E> graph, Reader input)	Import a graph.
boolean	isParameter(CSVFormat.Parameter p)	Return if a particular parameter of the exporter is enabled
void	setDelimiter(char delimiter)	Set the delimiter (comma, semicolon, pipe, etc).
void	setFormat(CSVFormat format)	Set the format of the importer
void	setParameter(CSVFormat.Parameter p, boolean value)	Set the value of a parameter of the exporter
void	setVertexFactory(Function<String,V> vertexFactory)	Set the user custom vertex factory.

Methods inherited from class BaseEventDrivenImporter

addEdgeAttributeConsumer, addEdgeConsumer, addEdgeCountConsumer, addEdgeWithAttributesConsumer, addGraphAttributeConsumer, addImportEventConsumer, addVertexAttributeConsumer, addVertexConsumer, addVertexCountConsumer, addVertexWithAttributesConsumer, notifyEdge, notifyEdgeAttribute, notifyEdgeCount, notifyEdgeWithAttributes, notifyGraphAttribute, notifyImportEvent, notifyVertex, notifyVertexAttribute, notifyVertexCount, notifyVertexWithAttributes, removeEdgeAttributeConsumer, removeEdgeConsumer, removeEdgeCountConsumer, removeEdgeWithAttributesConsumer, removeGraphAttributeConsumer, removeImportEventConsumer, removeVertexAttributeConsumer, removeVertexConsumer, removeVertexCountConsumer, removeVertexWithAttributesConsumer

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface GraphImporter

importGraph, importGraph

Field Details

DEFAULT_DELIMITER

private static final char DEFAULT_DELIMITER

See Also:

• Constant Field Values

DEFAULT_VERTEX_ID_KEY

private static final String DEFAULT_VERTEX_ID_KEY

See Also:

• Constant Field Values

DEFAULT_WEIGHT_KEY

private static final String DEFAULT_WEIGHT_KEY

See Also:

• Constant Field Values

format

private CSVFormat format

delimiter

private char delimiter

parameters

private final Set<CSVFormat.Parameter> parameters

vertexFactory

private Function<String,V> vertexFactory

Constructor Details

CSVImporter

public CSVImporter()

Constructs a new importer using the CSVFormat.ADJACENCY_LIST format as default.

CSVImporter

public CSVImporter(CSVFormat format)

Constructs a new importer.

Parameters:

format - format to use out of the supported ones

CSVImporter

public CSVImporter(CSVFormat format,
 char delimiter)

Constructs a new importer.

Parameters:

format - format to use out of the supported ones

delimiter - delimiter to use (comma, semicolon, pipe, etc.)

Method Details

getFormat

public CSVFormat getFormat()

Get the format that the importer is using.

Returns:

the input format

setFormat

public void setFormat(CSVFormat format)

Set the format of the importer

Parameters:

format - the format to use

getDelimiter

public char getDelimiter()

Get the delimiter (comma, semicolon, pipe, etc).

Returns:

the delimiter

setDelimiter

public void setDelimiter(char delimiter)

Set the delimiter (comma, semicolon, pipe, etc).

Parameters:

delimiter - the delimiter to use

isParameter

public boolean isParameter(CSVFormat.Parameter p)

Return if a particular parameter of the exporter is enabled

Parameters:

p - the parameter

Returns:

true if the parameter is set, false otherwise

setParameter

public void setParameter(CSVFormat.Parameter p,
 boolean value)

Set the value of a parameter of the exporter

Parameters:

p - the parameter

value - the value to set

getVertexFactory

public Function<String,V> getVertexFactory()

Get the user custom vertex factory. This is null by default and the graph supplier is used instead.

Returns:

the user custom vertex factory

setVertexFactory

public void setVertexFactory(Function<String,V> vertexFactory)

Set the user custom vertex factory. The default behavior is being null in which case the graph vertex supplier is used. If supplied the vertex factory is called every time a new vertex is encountered in the file. The method is called with parameter the vertex identifier from the file and should return the actual graph vertex to add to the graph.

Parameters:

vertexFactory - a vertex factory

importGraph

public void importGraph(Graph<V,E> graph,
 Reader input)
                 throws ImportException

Import a graph.

The provided graph must be able to support the features of the graph that is read. For example if the input contains self-loops then the graph provided must also support self-loops. The same for multiple edges.

If the provided graph is a weighted graph, the importer also reads edge weights.

Specified by:

importGraph in interface GraphImporter<V,E>

Parameters:

graph - the graph

input - the input reader

Throws:

ImportException - in case an error occurs, such as I/O or parse error