y.io
Class IOHandler

java.lang.Object
  y.io.IOHandler

Direct Known Subclasses:

GMLIOHandler, GraphMLIOHandler, ImageMapOutputHandler, ImageOutputHandler, TGFIOHandler, TiledImageOutputHandler, XmlXslIOHandler, YGFIOHandler

public abstract class IOHandler
extends Object

Abstract IO handler class. An IO handler is responsible for reading and/or writing graphs in a specific format from/to a stream

Constructor Summary

IOHandler()

Method Summary

boolean	canRead() Whether this file handler supports reading from a file.
boolean	canWrite() Whether this file handler supports writing to a file.
boolean	canWriteSubset() Whether this file handler supports writing graph subsets to a file.
static ObjectInputStream	createObjectInputStream(String name) Creates and returns an object input stream that is connected to a file.
static ObjectOutputStream	createObjectOutputStream(String name) Creates and returns an object output stream that is connected to a file.
abstract String	getFileFormatString() Returns a descriptive string of the supported file format.
abstract String	getFileNameExtension() Returns the file name extension of the supported file format.
protected void	hide(GraphHider hider, DataProvider dp) Uses the GraphHider to hide parts of the graph in order to write a subset.
abstract void	read(Graph2D graph, InputStream in) Adds the contents that are read from the stream to the given graph.
void	read(Graph2D graph, String name) Fills the contents of the given graph from a file.
void	read(Graph2D graph, URL url) Fills the contents of the given graph from a URL.
protected boolean	shouldSerialize(Edge edge, DataProvider dp) Determines whether the given edge should be serialized.
protected boolean	shouldSerialize(Node node, DataProvider dp) Determines whether the given node should be serialized.
abstract void	write(Graph2D graph, OutputStream out) Writes the contents of the given graph to a stream
void	write(Graph2D graph, String name) Writes the contents of the given graph to a file.
void	writeSubset(Graph2D graph, DataProvider dp, OutputStream out) Writes a subset of the contents of the given graph to a stream
void	writeSubset(Graph2D graph, DataProvider dp, String name) Writes a subset of the contents of the given graph to a stream

Methods inherited from class java.lang.Object

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

Constructor Detail

IOHandler

public IOHandler()

Method Detail

write

public abstract void write(Graph2D graph,
                           OutputStream out)
                    throws IOException

Writes the contents of the given graph to a stream

Throws:

IOException

writeSubset

public void writeSubset(Graph2D graph,
                        DataProvider dp,
                        OutputStream out)
                 throws IOException

Writes a subset of the contents of the given graph to a stream

Throws:

IOException

Parameters:

graph - the graph to be written out

dp - the data provider, which contains boolean information for each element, which indicates, whether this item should be serialized or not

read

public abstract void read(Graph2D graph,
                          InputStream in)
                   throws IOException

Adds the contents that are read from the stream to the given graph. The given graph will not be cleared when the content of the file will be added to it.

Throws:

IOException

getFileFormatString

public abstract String getFileFormatString()

Returns a descriptive string of the supported file format.

getFileNameExtension

public abstract String getFileNameExtension()

Returns the file name extension of the supported file format. The extension does not include the separating dot (i.e, '.').

write

public void write(Graph2D graph,
                  String name)
           throws IOException

Writes the contents of the given graph to a file.

Throws:

IOException

Parameters:

name - The name of the output file

writeSubset

public void writeSubset(Graph2D graph,
                        DataProvider dp,
                        String name)
                 throws IOException

Writes a subset of the contents of the given graph to a stream

Throws:

IOException

read

public void read(Graph2D graph,
                 String name)
          throws IOException

Fills the contents of the given graph from a file.

Throws:

IOException

Parameters:

name - The name of the file to be read.

read

public void read(Graph2D graph,
                 URL url)
          throws IOException

Fills the contents of the given graph from a URL.

Throws:

IOException

Parameters:

url - The url of the resource to be read.

createObjectInputStream

public static ObjectInputStream createObjectInputStream(String name)
                                                 throws IOException

Creates and returns an object input stream that is connected to a file.

Throws:

IOException

Parameters:

name - The name of the input file.

createObjectOutputStream

public static ObjectOutputStream createObjectOutputStream(String name)
                                                   throws IOException

Creates and returns an object output stream that is connected to a file.

Throws:

IOException

Parameters:

name - The name of the output file.

canRead

public boolean canRead()

Whether this file handler supports reading from a file.

canWrite

public boolean canWrite()

Whether this file handler supports writing to a file.

canWriteSubset

public boolean canWriteSubset()

Whether this file handler supports writing graph subsets to a file.

hide

protected void hide(GraphHider hider,
                    DataProvider dp)

Uses the GraphHider to hide parts of the graph in order to write a subset.

Parameters:

hider - the hider

dp - the data provider which tells which graph elements to serialize and which not

shouldSerialize

protected boolean shouldSerialize(Node node,
                                  DataProvider dp)

Determines whether the given node should be serialized. The information is obtained by examining the data provider

Parameters:

node - the node

dp - the data provider which tells which graph elements to serialize and which not

Returns:

true iff this elements should be serialized

shouldSerialize

protected boolean shouldSerialize(Edge edge,
                                  DataProvider dp)

Determines whether the given edge should be serialized. The information is obtained by examining the data provider

Parameters:

edge - the edge

dp - the data provider which tells which graph elements to serialize and which not

Returns:

true iff this elements should be serialized