uk.org.ogsadai.activity.files
Class FileAccessActivity

java.lang.Object
  |
  +--uk.org.ogsadai.activity.Activity
        |
        +--uk.org.ogsadai.activity.files.AbstractFileActivity
              |
              +--uk.org.ogsadai.activity.files.FileAccessActivity

public class FileAccessActivity

extends AbstractFileActivity

Reads a file or extracts part of a file. This file can be a text file or a binary file. For information on this activity see the OGSA-DAI user doc: OGSA-DAI/doc/interaction/activities/files/fileAccessActivity.html

Author:

The OGSA-DAI Team.

Field Summary

private static java.lang.String	COPYRIGHT_NOTICE Copyright statement
private static DAILogger	LOG Logger object for logging in this class
private boolean	mBase64encode Is file content to be Base64 encoded (default false).
private boolean	mBinaryFile Is the file a binary file (default true).
private java.io.File	mFile The file to read from.
private java.lang.String	mFilename The name of the file to read from
private int	mLength Number of bytes/characters to read
private int	mOffset Offset from start of file
private BlockWriter	mOutput Activity output - file content

Fields inherited from class uk.org.ogsadai.activity.files.AbstractFileActivity

mCredentials, mFileAccessProvider, mTopDir

Fields inherited from class uk.org.ogsadai.activity.Activity

mContext, mExternalInputs, mExternalOutputs, mInternalInputs, mInternalOutputs

Constructor Summary

FileAccessActivity(org.w3c.dom.Element element)

Method Summary

void	initialise() Gets the data resource accessor for the files data resource according to whether the users credentials permit this access.
void	processBlock() Performs an iteration of the processing of an activity.

Methods inherited from class uk.org.ogsadai.activity.Activity

cleanUp, connectsTo, createOutputPipe, getActivityConfiguration, getActivityName, getCause, getName, getObservableStatus, getProperties, getSession, getStatus, hasActivityConfiguration, hasProperties, process, processFirst, setActivityName, setCompleted, setError

Methods inherited from class java.lang.Object

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

Field Detail

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

Copyright statement

See Also:

Constant Field Values

LOG

private static final DAILogger LOG

Logger object for logging in this class

mFile

private java.io.File mFile

The file to read from.

mFilename

private java.lang.String mFilename

The name of the file to read from

mBase64encode

private boolean mBase64encode

Is file content to be Base64 encoded (default false).

mBinaryFile

private boolean mBinaryFile

Is the file a binary file (default true).

mOffset

private int mOffset

Offset from start of file

mLength

private int mLength

Number of bytes/characters to read

mOutput

private BlockWriter mOutput

Activity output - file content

Constructor Detail

FileAccessActivity

public FileAccessActivity(org.w3c.dom.Element element)
                   throws ActivitySpecificationException,
                          ActivityCreationException

Method Detail

initialise

public void initialise()
                throws ActivitySpecificationException,
                       ActivityExecutionException

Description copied from class: AbstractFileActivity

Gets the data resource accessor for the files data resource according to whether the users credentials permit this access.

Overrides:

initialise in class AbstractFileActivity

Throws:

ActivitySpecificationException - If the user is not permitted to access the resource.

ActivityExecutionException - If some internal problem occurs.

See Also:

Activity.initialise()

processBlock

public void processBlock()

Description copied from class: Activity

Performs an iteration of the processing of an activity. This may involve reading a block of input data and writing a block of output data, or may involve some other kind of processing. When an activity is processed by the OGSA-DAI engine, this method will be invoked repeatedly until the activity either completes or stops due to an error or termination call. An implementation of this method should invoke the setCompleted method to indicate that processing is complete, or the setError method if an error occurs that will prevent the processing from completing.

Specified by:

processBlock in class Activity