org.apache.tomcat.util.http.fileupload (Apache Tomcat 7.0.109 API Documentation)

Interface Summary
Interface	Description
FileItem	This class represents a file or form item that was received within a `multipart/form-data` POST request.
FileItemFactory	A factory interface for creating `FileItem` instances.
FileItemHeaders	This class provides support for accessing the headers for a file or form item that was received within a `multipart/form-data` POST request.
FileItemHeadersSupport	Interface that will indicate that `FileItem` or `FileItemStream` implementations will accept the headers read for the item.
FileItemIterator	An iterator, as returned by `FileUploadBase.getItemIterator(RequestContext)`.
FileItemStream	This interface provides access to a file or form item that was received within a `multipart/form-data` POST request.
ProgressListener	The `ProgressListener` may be used to display a progress bar or do stuff like that.
RequestContext	Abstracts access to the request information needed for file uploads.
UploadContext	Enhanced access to the request information needed for file uploads, which fixes the Content Length data access in `RequestContext`.

Class Summary
Class	Description
ByteArrayOutputStream	This class implements an output stream in which the data is written into a byte array.
DeferredFileOutputStream	An output stream which will retain data in memory until a specified threshold is reached, and only then commit it to disk.
FileUpload	High level API for processing file uploads.
FileUploadBase	High level API for processing file uploads.
FileUtils	General file manipulation utilities.
IOUtils	General IO stream manipulation utilities.
MultipartStream	Low level API for processing file uploads.
MultipartStream.ProgressNotifier	Internal class, which is used to invoke the `ProgressListener`.
ParameterParser	A simple parser intended to parse sequences of name/value pairs.
ThresholdingOutputStream	An output stream which triggers an event when a specified number of bytes of data have been written to it.

Exception Summary
Exception	Description
FileItemStream.ItemSkippedException	This exception is thrown, if an attempt is made to read data from the `InputStream`, which has been returned by `FileItemStream.openStream()`, after `Iterator.hasNext()` has been invoked on the iterator, which created the `FileItemStream`.
FileUploadException	Exception for errors encountered while processing the request.
InvalidFileNameException	This exception is thrown in case of an invalid file name.
MultipartStream.IllegalBoundaryException	Thrown upon attempt of setting an invalid boundary token.
MultipartStream.MalformedStreamException	Thrown to indicate that the input stream fails to follow the required syntax.

Package org.apache.tomcat.util.http.fileupload Description

NOTE: This code has been copied from commons-fileupload trunk 1.3 and commons-io 1.4 and package renamed to avoid clashes with any web apps that may wish to use these libraries.

A component for handling HTML file uploads as specified by RFC 1867. This component provides support for uploads within both servlets (JSR 53) and portlets (JSR 168).

While this package provides the generic functionality for file uploads, these classes are not typically used directly. Instead, normal usage involves one of the provided extensions of FileUpload such as ServletFileUpload together with a factory for FileItem instances, such as DiskFileItemFactory.

The following is a brief example of typical usage in a servlet, storing the uploaded files on disk.

public void doPost(HttpServletRequest req, HttpServletResponse res) {
   DiskFileItemFactory factory = new DiskFileItemFactory();
   // maximum size that will be stored in memory
   factory.setSizeThreshold(4096);
   // the location for saving data that is larger than getSizeThreshold()
   factory.setRepository(new File("/tmp"));

   ServletFileUpload upload = new ServletFileUpload(factory);
   // maximum size before a FileUploadException will be thrown
   upload.setSizeMax(1000000);

   List fileItems = upload.parseRequest(req);
   // assume we know there are two files. The first file is a small
   // text file, the second is unknown and is written to a file on
   // the server
   Iterator i = fileItems.iterator();
   String comment = ((FileItem)i.next()).getString();
   FileItem fi = (FileItem)i.next();
   // file name on the client
   String fileName = fi.getName();
   // save comment and file name to database
   ...
   // write the file
   fi.write(new File("/www/uploads/", fileName));
 }

In the example above, the first file is loaded into memory as a String. Before calling the getString method, the data may have been in memory or on disk depending on its size. The second file we assume it will be large and therefore never explicitly load it into memory, though if it is less than 4096 bytes it will be in memory before it is written to its final location. When writing to the final location, if the data is larger than the threshold, an attempt is made to rename the temporary file to the given location. If it cannot be renamed, it is streamed to the new location.

Please see the FileUpload User Guide for further details and examples of how to use this package.