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Class oracle.forms.demos.uploadclient.FileUploader
java.lang.Object
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+----java.awt.Component
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+----java.awt.Container
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+----oracle.ewt.lwAWT.LWComponent
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+----oracle.ewt.lwAWT.LWContainer
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+----oracle.forms.ui.VBean
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+----oracle.forms.demos.uploadclient.FileUploader
- public class FileUploader
- extends VBean
This component facilitates the sending of files from the Forms Java client to
the Forms server. It allows the user to select a file to be sent to the server
and then performs the necessary operations required to send the file over the
Forms message connection to the server.
Since the Forms server is not able to handle byte data from it's PL/SQL environment
the user selected file is first transformed into a textual representation, using
the BASE64 encoding scheme for sending to the server.
To further aid in the sending of this textual data to the Forms server, the
encoded file is broken into 4K chunks before sending and each chunk is
dispatched individually. It is up to the Forms server to process these chunks
and reassemble them into a useful data set.
To reduce the amount of data sent across the network the source file is
compressed before encoding. This facility can be turned off if the files
being transferred are already compressed e.g. ZIP files
Since the encoding, chunking and dispatching processes can take a significant amount
of time on slower networks/large files, the FileUploader utilizes a ProgressBar to
indicate to the end user that actions are being performed.
- Version:
- 1.2
- Author:
- Steve Button, Duncan Mills
-
FileUploader()
- Creates a new instance of the FileUploader class.
-
init(IHandler)
- Method from the oracle.forms.ui.IView class and overriden from the VBean
base class.
-
loadFile(Object, boolean)
- Facilitates the sending of a user selected file back to the Forms Server
encoded using the BASE64 encoding scheme.
Enables the user to make a file selection using the standard AWT file dialog.
Optionally Zips the file
Encodes the file using the sun.misc.BASE64Encoder class.
Sends the encoded data back in segments of size CHUNKSIZE.
-
log(String)
- Writes debugging messages to the Java Console when the DEBUGMESSAGES property has been set on the bean.
-
main(String[])
-
-
setProperty(ID, Object)
- Overriding method from the IView interface.
FileUploader
public FileUploader()
- Creates a new instance of the FileUploader class.
init
public void init(IHandler handler)
- Method from the oracle.forms.ui.IView class and overriden from the VBean
base class. This lifecycle method is called once when Forms creates an
instance of the JavaBean.
- Parameters:
- handler - a reference to the Handler class for this JavaBean.
- Overrides:
- init in class VBean
setProperty
public boolean setProperty(ID pid,
Object value)
- Overriding method from the IView interface. Allows the values of properties
to be retrieved when called from the Oracle Forms Server runtime. This method
allows the Forms Server to get both standard and custom properties. The standard
properties such as FOREGROUND, FONT, etc. all have type mappings performed
by the Forms engine itself so these can simply be passed from their analog
accessor methods on the JavaBean. For the custom properties, sometimes
type translation is required since Forms will only allow a String
type as a return value for a custom property.
- Parameters:
- pid - the property to be retrieved, identified by it's ID
- Object - the value of the requested property
- Returns:
- The outcome of the operation.
- Overrides:
- setProperty in class VBean
loadFile
protected boolean loadFile(Object value,
boolean namedFile)
- Facilitates the sending of a user selected file back to the Forms Server
encoded using the BASE64 encoding scheme.
Enables the user to make a file selection using the standard AWT file dialog.
Optionally Zips the file
Encodes the file using the sun.misc.BASE64Encoder class.
Sends the encoded data back in segments of size CHUNKSIZE.
- Parameters:
- value - sent with the LOADFILE or LOADNAMEDFILE property from
the Forms Server, used to indicate the starting directory the filedialog
should use if the second argument is false, or the name of the actual file
to load (bypassing dialog) if the second argument is true
- namedFile - indicates that the supplied value is for a specific file to upload.
- Returns:
- The outcome of the operation.
log
public void log(String msg)
- Writes debugging messages to the Java Console when the DEBUGMESSAGES property has been set on the bean.
- Parameters:
- msg - the console output
main
public static void main(String args[])
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