info.sswap.ontologies.data.impl
Class ResourceData

java.lang.Object
  info.sswap.ontologies.data.impl.AbstractData
      info.sswap.ontologies.data.impl.ResourceData

All Implemented Interfaces:

Accessor, Data, Parser, Serializer, Validator

Direct Known Subclasses:

HTTPBasicAuthImpl

public class ResourceData
extends AbstractData
implements Accessor

Support for reading and writing resource data (data at the URL of an individual; usually a SSWAPSubject or SSWAPObject).

Author:

Damian Gessler

Field Summary

protected java.net.URLConnection

urlConnection

Fields inherited from class info.sswap.ontologies.data.impl.AbstractData

DataFormatType, sswapDocument, sswapIndividual

Constructor Summary

ResourceData(SSWAPIndividual sswapIndividual)
Constructs an individual suitable for reading/writing data

Method Summary

java.net.URLConnection	access(java.net.URLConnection urlConnection) Default implementation just passes urlConnection untouched.
void	close() Closes the URL connection and sets it to null.
protected void	finalize()
java.net.URLConnection	getConnection() Get the underlying URL connection.
protected java.net.URL	getURLConnection() Return the first, valid Accessor URL, or the individual's URL if there are no accessors.
java.io.InputStream	readData() Accesses, parses, and validates the data from the URL of the data individual.
void	writeData(java.io.InputStream inputStream) Accesses, validates, and serializes the data to the URL of the data individual.

Methods inherited from class info.sswap.ontologies.data.impl.AbstractData

getAccessors, getFormats, getParsers, getSerializers, getValidators, hasValue, inputStreamToString, parse, serialize, setValue, stringToInputStream, validate

Methods inherited from class java.lang.Object

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

Field Detail

urlConnection

protected java.net.URLConnection urlConnection

Constructor Detail

ResourceData

public ResourceData(SSWAPIndividual sswapIndividual)
             throws DataException

Constructs an individual suitable for reading/writing data

Parameters:

sswapIndividual - the subject data individual

Throws:

DataException - on any error establishing resource data support

Method Detail

readData

public java.io.InputStream readData()
                             throws java.io.IOException,
                                    DataException

Accesses, parses, and validates the data from the URL of the data individual. Order of processing is to call the access, parse, and validate methods, any of which may be overridden.

The data source must be of type data:DataFormat for any meaningful read; otherwise a read immediately "succeeds" with trivial empty content.

Specified by:

readData in interface Data

Returns:

InputStream a stream to read the data

Throws:

java.io.IOException - on any read error

DataException - on data error such as parsing, validating, etc.

writeData

public void writeData(java.io.InputStream inputStream)
               throws java.io.IOException,
                      DataException

Accesses, validates, and serializes the data to the URL of the data individual. Order of processing is to call the access, validate, and serialize methods, any of which may be overridden. Caller should close inputStream when done; opened URL connection will be closed automatically on success only. On failure (e.g., a thrown exception), use getConnection to get the underlying connection for error handling. Connection should be then closed by caller when done.

Specified by:

writeData in interface Data

Parameters:

inputStream - data to be written

Throws:

java.io.IOException - on any write error

DataException - on data error such as validating, serializing, etc.

See Also:

getConnection()

getURLConnection

protected java.net.URL getURLConnection()
                                 throws DataException

Return the first, valid Accessor URL, or the individual's URL if there are no accessors.

Returns:

url URL for the individual or one of its accessors

Throws:

DataException - inability to establish any URL for this individual

access

public java.net.URLConnection access(java.net.URLConnection urlConnection)
                              throws java.io.IOException,
                                     AccessorException

Default implementation just passes urlConnection untouched. Custom implementations may extend this class and override this method. Note that accessing is a filter: accepting the urlConnection to access and returning the urlConnection for the next downstream step to read or write.

Specified by:

access in interface Accessor

Parameters:

urlConnection - a URL connection opened on the data element individual (the individual itself or one of its Accessors)

Returns:

URLConnection open URL connection

Throws:

java.io.IOException - on any connection error

AccessorException - on any Accessor-specific error

See Also:

HTTPBasicAuthImpl

getConnection

public java.net.URLConnection getConnection()

Get the underlying URL connection. This method is usually only needed to act on read or write error conditions.

Returns:

the URL connection; null if not set

close

public void close()

Closes the URL connection and sets it to null.

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable