org.apache.tomcat.util.http.fileupload

Interface FileItem

public interface FileItem extends Serializable

This class represents a file or form item that was received within a multipart/form-data POST request.

After retrieving an instance of this class from a FileUpload instance (see #parseRequest(javax.servlet.http.HttpServletRequest)), you may either request all contents of the file at once using get or request an java.io.InputStream InputStream with getInputStream and process the file without attempting to load it into memory, which may come handy with large files.

While this interface does not extend javax.activation.DataSource per se (to avoid a seldom used dependency), several of the defined methods are specifically defined with the same signatures as methods in that interface. This allows an implementation of this interface to also implement javax.activation.DataSource with minimal additional work.

Version: $Id: FileItem.java 467222 2006-10-24 03:17:11Z markt $

Author: Rafal Krzewski Sean Legassick Jason van Zyl Martin Cooper

Method Summary
voiddelete()
Deletes the underlying storage for a file item, including deleting any associated temporary disk file.
byte[]get()
Returns the contents of the file item as an array of bytes.
StringgetContentType()
Returns the content type passed by the browser or null if not defined.
StringgetFieldName()
Returns the name of the field in the multipart form corresponding to this file item.
InputStreamgetInputStream()
Returns an java.io.InputStream InputStream that can be used to retrieve the contents of the file.
StringgetName()
Returns the original filename in the client's filesystem, as provided by the browser (or other client software).
OutputStreamgetOutputStream()
Returns an java.io.OutputStream OutputStream that can be used for storing the contents of the file.
longgetSize()
Returns the size of the file item.
StringgetString(String encoding)
Returns the contents of the file item as a String, using the specified encoding.
StringgetString()
Returns the contents of the file item as a String, using the default character encoding.
booleanisFormField()
Determines whether or not a FileItem instance represents a simple form field.
booleanisInMemory()
Provides a hint as to whether or not the file contents will be read from memory.
voidsetFieldName(String name)
Sets the field name used to reference this file item.
voidsetFormField(boolean state)
Specifies whether or not a FileItem instance represents a simple form field.
voidwrite(File file)
A convenience method to write an uploaded item to disk.

Method Detail

delete

public void delete()
Deletes the underlying storage for a file item, including deleting any associated temporary disk file. Although this storage will be deleted automatically when the FileItem instance is garbage collected, this method can be used to ensure that this is done at an earlier time, thus preserving system resources.

get

public byte[] get()
Returns the contents of the file item as an array of bytes.

Returns: The contents of the file item as an array of bytes.

getContentType

public String getContentType()
Returns the content type passed by the browser or null if not defined.

Returns: The content type passed by the browser or null if not defined.

getFieldName

public String getFieldName()
Returns the name of the field in the multipart form corresponding to this file item.

Returns: The name of the form field.

getInputStream

public InputStream getInputStream()
Returns an java.io.InputStream InputStream that can be used to retrieve the contents of the file.

Returns: An java.io.InputStream InputStream that can be used to retrieve the contents of the file.

Throws: IOException if an error occurs.

getName

public String getName()
Returns the original filename in the client's filesystem, as provided by the browser (or other client software). In most cases, this will be the base file name, without path information. However, some clients, such as the Opera browser, do include path information.

Returns: The original filename in the client's filesystem.

getOutputStream

public OutputStream getOutputStream()
Returns an java.io.OutputStream OutputStream that can be used for storing the contents of the file.

Returns: An java.io.OutputStream OutputStream that can be used for storing the contensts of the file.

Throws: IOException if an error occurs.

getSize

public long getSize()
Returns the size of the file item.

Returns: The size of the file item, in bytes.

getString

public String getString(String encoding)
Returns the contents of the file item as a String, using the specified encoding. This method uses get to retrieve the contents of the item.

Parameters: encoding The character encoding to use.

Returns: The contents of the item, as a string.

Throws: UnsupportedEncodingException if the requested character encoding is not available.

getString

public String getString()
Returns the contents of the file item as a String, using the default character encoding. This method uses get to retrieve the contents of the item.

Returns: The contents of the item, as a string.

isFormField

public boolean isFormField()
Determines whether or not a FileItem instance represents a simple form field.

Returns: true if the instance represents a simple form field; false if it represents an uploaded file.

isInMemory

public boolean isInMemory()
Provides a hint as to whether or not the file contents will be read from memory.

Returns: true if the file contents will be read from memory; false otherwise.

setFieldName

public void setFieldName(String name)
Sets the field name used to reference this file item.

Parameters: name The name of the form field.

setFormField

public void setFormField(boolean state)
Specifies whether or not a FileItem instance represents a simple form field.

Parameters: state true if the instance represents a simple form field; false if it represents an uploaded file.

write

public void write(File file)
A convenience method to write an uploaded item to disk. The client code is not concerned with whether or not the item is stored in memory, or on disk in a temporary location. They just want to write the uploaded item to a file.

This method is not guaranteed to succeed if called more than once for the same item. This allows a particular implementation to use, for example, file renaming, where possible, rather than copying all of the underlying data, thus gaining a significant performance benefit.

Parameters: file The File into which the uploaded item should be stored.

Throws: Exception if an error occurs.

Copyright © 2000-2011 Apache Software Foundation. All Rights Reserved.