org.apache.struts.actions
Class DownloadAction
public abstract class DownloadAction
This is an abstract base class that minimizes the amount of special coding
that needs to be written to download a file. All that is required to use
this class is to extend it and implement the getStreamInfo()
method so that it returns the relevant information for the file (or other
stream) to be downloaded. Optionally, the getBufferSize()
method may be overridden to customize the size of the buffer used to
transfer the file.
static class | DownloadAction.FileStreamInfo - A concrete implementation of the
StreamInfo interface which
simplifies the downloading of a file from the disk.
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static class | DownloadAction.ResourceStreamInfo - A concrete implementation of the
StreamInfo interface which
simplifies the downloading of a web application resource.
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static interface | DownloadAction.StreamInfo - The information on a file, or other stream, to be downloaded by the
DownloadAction .
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protected static int | DEFAULT_BUFFER_SIZE - If the
getBufferSize() method is not overridden, this is
the buffer size that will be used to transfer the data to the servlet
output stream.
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int | copy(InputStream input, OutputStream output) - Copy bytes from an
InputStream to an
OutputStream .
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ActionForward | execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) - Process the specified HTTP request, and create the corresponding HTTP
response (or forward to another web component that will create it).
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protected int | getBufferSize() - Returns the size of the buffer to be used in transferring the data to
the servlet output stream.
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protected abstract DownloadAction.StreamInfo | getStreamInfo(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) - Returns the information on the file, or other stream, to be downloaded
by this action.
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addErrors , addMessages , execute , execute , generateToken , getDataSource , getDataSource , getErrors , getLocale , getMessages , getResources , getResources , getServlet , isCancelled , isTokenValid , isTokenValid , resetToken , saveErrors , saveErrors , saveErrors , saveMessages , saveMessages , saveToken , setLocale , setServlet |
DEFAULT_BUFFER_SIZE
protected static final int DEFAULT_BUFFER_SIZE
If the getBufferSize()
method is not overridden, this is
the buffer size that will be used to transfer the data to the servlet
output stream.
copy
public int copy(InputStream input,
OutputStream output)
throws IOException
Copy bytes from an InputStream
to an
OutputStream
.
input
- The InputStream
to read from.output
- The OutputStream
to write to.
- the number of bytes copied
execute
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception
Process the specified HTTP request, and create the corresponding HTTP
response (or forward to another web component that will create it).
Return an ActionForward
instance describing where and how
control should be forwarded, or null
if the response has
already been completed.
- execute in interface Action
mapping
- The ActionMapping used to select this instance.form
- The optional ActionForm bean for this request (if any).request
- The HTTP request we are processing.response
- The HTTP response we are creating.
getBufferSize
protected int getBufferSize()
Returns the size of the buffer to be used in transferring the data to
the servlet output stream. This method may be overridden by an extending
class in order to customize the buffer size.
- The size of the transfer buffer, in bytes.
getStreamInfo
protected abstract DownloadAction.StreamInfo getStreamInfo(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception
Returns the information on the file, or other stream, to be downloaded
by this action. This method must be implemented by an extending class.
mapping
- The ActionMapping used to select this instance.form
- The optional ActionForm bean for this request (if any).request
- The HTTP request we are processing.response
- The HTTP response we are creating.
- The information for the file to be downloaded.
Copyright B) 2000-2007 - The Apache Software Foundation