org.apache.tomcat.util.http.fileupload

Class DefaultFileItem

public class DefaultFileItem extends Object implements FileItem

The default implementation of the FileItem interface.

After retrieving an instance of this class from a DiskFileUpload instance (see #parseRequest(javax.servlet.http.HttpServletRequest)), you may either request all contents of 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.

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

Author: Rafal Krzewski Sean Legassick Jason van Zyl John McNally Martin Cooper Sean C. Sullivan

Method Summary
voiddelete()
Deletes the underlying storage for a file item, including deleting any associated temporary disk file.
protected voidfinalize()
Removes the file contents from the temporary storage.
byte[]get()
Returns the contents of the file 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.
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.
FilegetStoreLocation()
Returns the java.io.File object for the FileItem's data's temporary location on the disk.
StringgetString(String encoding)
Returns the contents of the file as a String, using the specified encoding.
StringgetString()
Returns the contents of the file as a String, using the default character encoding.
protected FilegetTempFile()
Creates and returns a java.io.File File representing a uniquely named temporary file in the configured repository path.
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 fieldName)
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.

finalize

protected void finalize()
Removes the file contents from the temporary storage.

get

public byte[] get()
Returns the contents of the file as an array of bytes. If the contents of the file were not yet cached in memory, they will be loaded from the disk storage and cached.

Returns: The contents of the file 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.

See Also:

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.

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.

Returns: The size of the file, in bytes.

getStoreLocation

public File getStoreLocation()
Returns the java.io.File object for the FileItem's data's temporary location on the disk. Note that for FileItems that have their data stored in memory, this method will return null. When handling large files, you can use java.io.File#renameTo(java.io.File) to move the file to new location without copying the data, if the source and destination locations reside within the same logical volume.

Returns: The data file, or null if the data is stored in memory.

getString

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

Parameters: encoding The character encoding to use.

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

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

getString

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

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

getTempFile

protected File getTempFile()
Creates and returns a java.io.File File representing a uniquely named temporary file in the configured repository path.

Returns: The java.io.File File to be used for temporary storage.

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.

See Also:

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 fieldName)
Sets the field name used to reference this file item.

Parameters: fieldName The name of the form field.

See Also:

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.

See Also:

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 implementation first attempts to rename the uploaded item to the specified destination file, if the item was originally written to disk. Otherwise, the data will be copied to the specified file.

This method is only guaranteed to work once, the first time it is invoked for a particular item. This is because, in the event that the method renames a temporary file, that file will no longer be available to copy or rename again at a later time.

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

Throws: Exception if an error occurs.

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