com.compoze.util.upload
Class DefaultFileItem

java.lang.Object

  |

  +--com.compoze.util.upload.DefaultFileItem

All Implemented Interfaces:

FileItem, java.io.Serializable

public class DefaultFileItem

extends java.lang.Object

implements FileItem

The default mplementation of the FileItem interface.

After retrieving an instance of this class from a FileUpload instance (see #parseRequest(javax.servlet.http.HttpServletRequest)), you may either request all contents of file at once using get() or request an 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,v 1.1.1.1 2003/09/12 13:12:45 fred.grafe Exp $

See Also:

Serialized Form

Fields inherited from interface com.compoze.util.upload.FileItem

DEFAULT_UPLOAD_SIZE_THRESHOLD

Constructor Summary

	DefaultFileItem() Default constructor.
protected	DefaultFileItem(java.lang.String fileName, java.lang.String contentType) Constructs a new DefaultFileItem instance.

Method Summary

void	delete() Deletes the underlying storage for a file item, including deleting any associated temporary disk file.
protected void	finalize() Removes the file contents from the temporary storage.
byte[]	get() Returns the contents of the file as an array of bytes.
java.lang.String	getContentType() Returns the content type passed by the browser or null if not defined.
javax.activation.DataHandler	getDataHandler() Gets a data handler for the file item (a FileDataHandler if stored in a file, or a regular DataHandler if not).
java.lang.String	getFieldName() Returns the name of the field in the multipart form corresponding to this file item.
java.io.InputStream	getInputStream() Returns an InputStream that can be used to retrieve the contents of the file.
java.lang.String	getName() Returns the original filename in the client's filesystem.
java.io.OutputStream	getOutputStream() Returns an OutputStream that can be used for storing the contents of the file.
long	getSize() Returns the size of the file.
java.io.File	getStoreLocation() Returns the File object for the FileItem's data's temporary location on the disk.
java.lang.String	getString() Returns the contents of the file as a String, using the default character encoding.
java.lang.String	getString(java.lang.String encoding) Returns the contents of the file as a String, using the specified encoding.
boolean	isFormField() Determines whether or not a FileItem instance represents a simple form field.
boolean	isInMemory() Provides a hint as to whether or not the file contents will be read from memory.
static FileItem	newInstance(java.lang.String path, java.lang.String name, java.lang.String contentType, int requestSize, int threshold) Instantiates a DefaultFileItem.
void	setFieldName(java.lang.String fieldName) Sets the field name used to reference this file item.
void	setIsFormField(boolean state) Specifies whether or not a FileItem instance represents a simple form field.
void	write(java.lang.String file) A convenience method to write an uploaded file to disk.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DefaultFileItem

public DefaultFileItem()

Default constructor.

DefaultFileItem

protected DefaultFileItem(java.lang.String fileName,
                          java.lang.String contentType)

Constructs a new DefaultFileItem instance.

Use newInstance(String,String,String,int,int) to instantiate DefaultFileItems.

Parameters:

fileName - The original filename in the user's filesystem.

contentType - The content type passed by the browser or null if not defined.

Method Detail

getDataHandler

public javax.activation.DataHandler getDataHandler()

Gets a data handler for the file item (a FileDataHandler if stored in a file, or a regular DataHandler if not).

Specified by:

getDataHandler in interface FileItem

Returns:

an appropriate DataHandler for the data

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.io.IOException

Returns an InputStream that can be used to retrieve the contents of the file.

Specified by:

getInputStream in interface FileItem

Returns:

An InputStream that can be used to retrieve the contents of the file.

Throws:

java.io.IOException - if an error occurs.

getContentType

public java.lang.String getContentType()

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

Specified by:

getContentType in interface FileItem

Returns:

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

getName

public java.lang.String getName()

Returns the original filename in the client's filesystem.

Specified by:

getName in interface FileItem

Returns:

The original filename in the client's filesystem.

isInMemory

public boolean isInMemory()

Provides a hint as to whether or not the file contents will be read from memory.

Specified by:

isInMemory in interface FileItem

Returns:

true if the file contents will be read from memory.

getSize

public long getSize()

Returns the size of the file.

Specified by:

getSize in interface FileItem

Returns:

The size of the file, in bytes.

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.

Specified by:

get in interface FileItem

Returns:

The contents of the file as an array of bytes.

getString

public java.lang.String getString(java.lang.String encoding)
                           throws java.io.UnsupportedEncodingException

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

Specified by:

getString in interface FileItem

Parameters:

encoding - The character encoding to use.

Returns:

The contents of the file, as a string.

Throws:

java.io.UnsupportedEncodingException - if the requested character encoding is not available.

getString

public java.lang.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.

Specified by:

getString in interface FileItem

Returns:

The contents of the file, as a string.

getStoreLocation

public java.io.File getStoreLocation()

Returns the 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 File.renameTo(File) to move the file to new location without copying the data, if the source and destination locations reside within the same logical volume.

Specified by:

getStoreLocation in interface FileItem

Returns:

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

write

public void write(java.lang.String file)
           throws java.lang.Exception

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

Specified by:

write in interface FileItem

Parameters:

file - The full path to location where the uploaded file should be stored.

Throws:

java.lang.Exception - if an error occurs.

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.

Specified by:

delete in interface FileItem

getFieldName

public java.lang.String getFieldName()

Returns the name of the field in the multipart form corresponding to this file item.

Specified by:

getFieldName in interface FileItem

Returns:

The name of the form field.

setFieldName

public void setFieldName(java.lang.String fieldName)

Sets the field name used to reference this file item.

Specified by:

setFieldName in interface FileItem

Parameters:

fieldName - The name of the form field.

isFormField

public boolean isFormField()

Determines whether or not a FileItem instance represents a simple form field.

Specified by:

isFormField in interface FileItem

Returns:

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

setIsFormField

public void setIsFormField(boolean state)

Specifies whether or not a FileItem instance represents a simple form field.

Specified by:

setIsFormField in interface FileItem

Parameters:

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

getOutputStream

public java.io.OutputStream getOutputStream()
                                     throws java.io.IOException

Returns an OutputStream that can be used for storing the contents of the file.

Specified by:

getOutputStream in interface FileItem

Returns:

An OutputStream that can be used for storing the contensts of the file.

Throws:

java.io.IOException - if an error occurs.

finalize

protected void finalize()

Removes the file contents from the temporary storage.

Overrides:

finalize in class java.lang.Object

newInstance

public static FileItem newInstance(java.lang.String path,
                                   java.lang.String name,
                                   java.lang.String contentType,
                                   int requestSize,
                                   int threshold)

Instantiates a DefaultFileItem. It uses requestSize to decide what temporary storage approach the new item should take.

Parameters:

path - The path under which temporary files should be created.

name - The original filename in the client's filesystem.

contentType - The content type passed by the browser, or null if not defined.

requestSize - The total size of the POST request this item belongs to.

threshold - The maximum size to store in memory.

Returns:

A DefaultFileItem instance.