Class DiskFileItem
- java.lang.Object
-
- org.apache.commons.fileupload.disk.DiskFileItem
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- All Implemented Interfaces:
FileItem
,FileItemHeadersSupport
- Direct Known Subclasses:
DefaultFileItem
public class DiskFileItem extends java.lang.Object implements FileItem
The default implementation of the
FileItem
interface.After retrieving an instance of this class from a
DiskFileItemFactory
instance (see#parseRequest(javax.servlet.http.HttpServletRequest)
), you may either request all contents of file at once usingget()
or request anInputStream
withgetInputStream()
and process the file without attempting to load it into memory, which may come handy with large files.Temporary files, which are created for file items, should be deleted later on. The best way to do this is using a
FileCleaningTracker
, which you can set on theDiskFileItemFactory
. However, if you do use such a tracker, then you must consider the following: Temporary files are automatically deleted as soon as they are no longer needed. (More precisely, when the corresponding instance ofFile
is garbage collected.) This is done by the so-called reaper thread, which is started and stopped automatically by theFileCleaningTracker
when there are files to be tracked. It might make sense to terminate that thread, for example, if your web application ends. See the section on "Resource cleanup" in the users guide of commons-fileupload.- Since:
- FileUpload 1.1
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Field Summary
Fields Modifier and Type Field Description private byte[]
cachedContent
Cached contents of the file.private java.lang.String
contentType
The content type passed by the browser, ornull
if not defined.private static java.util.concurrent.atomic.AtomicInteger
COUNTER
Counter used in unique identifier generation.static java.lang.String
DEFAULT_CHARSET
Default content charset to be used when no explicit charset parameter is provided by the sender.private java.lang.String
defaultCharset
Default content charset to be used when no explicit charset parameter is provided by the sender.private org.apache.commons.io.output.DeferredFileOutputStream
dfos
Output stream for this item.private java.lang.String
fieldName
The name of the form field as provided by the browser.private java.lang.String
fileName
The original filename in the user's filesystem.private FileItemHeaders
headers
The file items headers.private boolean
isFormField
Whether or not this item is a simple form field.private java.io.File
repository
The directory in which uploaded files will be stored, if stored on disk.private long
size
The size of the item, in bytes.private int
sizeThreshold
The threshold above which uploads will be stored on disk.private java.io.File
tempFile
The temporary file to use.private static java.lang.String
UID
UID used in unique file name generation.
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Constructor Summary
Constructors Constructor Description DiskFileItem(java.lang.String fieldName, java.lang.String contentType, boolean isFormField, java.lang.String fileName, int sizeThreshold, java.io.File repository)
Constructs a newDiskFileItem
instance.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description 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
getCharSet()
Returns the content charset passed by the agent ornull
if not defined.java.lang.String
getContentType()
Returns the content type passed by the agent ornull
if not defined.java.lang.String
getDefaultCharset()
Returns the default charset for use when no explicit charset parameter is provided by the sender.java.lang.String
getFieldName()
Returns the name of the field in the multipart form corresponding to this file item.FileItemHeaders
getHeaders()
Returns the file item headers.java.io.InputStream
getInputStream()
Returns anInputStream
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 anOutputStream
that can be used for storing the contents of the file.long
getSize()
Returns the size of the file.java.io.File
getStoreLocation()
Returns theFile
object for theFileItem
'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 charset)
Returns the contents of the file as a String, using the specified encoding.protected java.io.File
getTempFile()
Creates and returns aFile
representing a uniquely named temporary file in the configured repository path.private static java.lang.String
getUniqueId()
Returns an identifier that is unique within the class loader used to load this class, but does not have random-like appearance.boolean
isFormField()
Determines whether or not aFileItem
instance represents a simple form field.boolean
isInMemory()
Provides a hint as to whether or not the file contents will be read from memory.void
setDefaultCharset(java.lang.String charset)
Sets the default charset for use when no explicit charset parameter is provided by the sender.void
setFieldName(java.lang.String fieldName)
Sets the field name used to reference this file item.void
setFormField(boolean state)
Specifies whether or not aFileItem
instance represents a simple form field.void
setHeaders(FileItemHeaders pHeaders)
Sets the file item headers.java.lang.String
toString()
Returns a string representation of this object.void
write(java.io.File file)
A convenience method to write an uploaded item to disk.
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Field Detail
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DEFAULT_CHARSET
public static final java.lang.String DEFAULT_CHARSET
Default content charset to be used when no explicit charset parameter is provided by the sender. Media subtypes of the "text" type are defined to have a default charset value of "ISO-8859-1" when received via HTTP.- See Also:
- Constant Field Values
-
UID
private static final java.lang.String UID
UID used in unique file name generation.
-
COUNTER
private static final java.util.concurrent.atomic.AtomicInteger COUNTER
Counter used in unique identifier generation.
-
fieldName
private java.lang.String fieldName
The name of the form field as provided by the browser.
-
contentType
private final java.lang.String contentType
The content type passed by the browser, ornull
if not defined.
-
isFormField
private boolean isFormField
Whether or not this item is a simple form field.
-
fileName
private final java.lang.String fileName
The original filename in the user's filesystem.
-
size
private long size
The size of the item, in bytes. This is used to cache the size when a file item is moved from its original location.
-
sizeThreshold
private final int sizeThreshold
The threshold above which uploads will be stored on disk.
-
repository
private final java.io.File repository
The directory in which uploaded files will be stored, if stored on disk.
-
cachedContent
private byte[] cachedContent
Cached contents of the file.
-
dfos
private transient org.apache.commons.io.output.DeferredFileOutputStream dfos
Output stream for this item.
-
tempFile
private transient java.io.File tempFile
The temporary file to use.
-
headers
private FileItemHeaders headers
The file items headers.
-
defaultCharset
private java.lang.String defaultCharset
Default content charset to be used when no explicit charset parameter is provided by the sender.
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Constructor Detail
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DiskFileItem
public DiskFileItem(java.lang.String fieldName, java.lang.String contentType, boolean isFormField, java.lang.String fileName, int sizeThreshold, java.io.File repository)
Constructs a newDiskFileItem
instance.- Parameters:
fieldName
- The name of the form field.contentType
- The content type passed by the browser ornull
if not specified.isFormField
- Whether or not this item is a plain form field, as opposed to a file upload.fileName
- The original filename in the user's filesystem, ornull
if not specified.sizeThreshold
- The threshold, in bytes, below which items will be retained in memory and above which they will be stored as a file.repository
- The data repository, which is the directory in which files will be created, should the item size exceed the threshold.
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Method Detail
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getInputStream
public java.io.InputStream getInputStream() throws java.io.IOException
Returns anInputStream
that can be used to retrieve the contents of the file.- Specified by:
getInputStream
in interfaceFileItem
- 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 agent ornull
if not defined.- Specified by:
getContentType
in interfaceFileItem
- Returns:
- The content type passed by the agent or
null
if not defined.
-
getCharSet
public java.lang.String getCharSet()
Returns the content charset passed by the agent ornull
if not defined.- Returns:
- The content charset passed by the agent or
null
if not defined.
-
getName
public java.lang.String getName()
Returns the original filename in the client's filesystem.- Specified by:
getName
in interfaceFileItem
- Returns:
- The original filename in the client's filesystem.
- Throws:
InvalidFileNameException
- The file name contains a NUL character, which might be an indicator of a security attack. If you intend to use the file name anyways, catch the exception and useInvalidFileNameException.getName()
.
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isInMemory
public boolean isInMemory()
Provides a hint as to whether or not the file contents will be read from memory.- Specified by:
isInMemory
in interfaceFileItem
- Returns:
true
if the file contents will be read from memory;false
otherwise.
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getSize
public long getSize()
Returns the size of the file.
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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.
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getString
public java.lang.String getString(java.lang.String charset) throws java.io.UnsupportedEncodingException
Returns the contents of the file as a String, using the specified encoding. This method usesget()
to retrieve the contents of the file.
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getString
public java.lang.String getString()
Returns the contents of the file as a String, using the default character encoding. This method usesget()
to retrieve the contents of the file. TODO Consider making this method throw UnsupportedEncodingException.
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write
public void write(java.io.File file) throws java.lang.Exception
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.
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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 theFileItem
instance is garbage collected, this method can be used to ensure that this is done at an earlier time, thus preserving system resources.
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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 interfaceFileItem
- Returns:
- The name of the form field.
- See Also:
setFieldName(java.lang.String)
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setFieldName
public void setFieldName(java.lang.String fieldName)
Sets the field name used to reference this file item.- Specified by:
setFieldName
in interfaceFileItem
- Parameters:
fieldName
- The name of the form field.- See Also:
getFieldName()
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isFormField
public boolean isFormField()
Determines whether or not aFileItem
instance represents a simple form field.- Specified by:
isFormField
in interfaceFileItem
- Returns:
true
if the instance represents a simple form field;false
if it represents an uploaded file.- See Also:
setFormField(boolean)
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setFormField
public void setFormField(boolean state)
Specifies whether or not aFileItem
instance represents a simple form field.- Specified by:
setFormField
in interfaceFileItem
- Parameters:
state
-true
if the instance represents a simple form field;false
if it represents an uploaded file.- See Also:
isFormField()
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getOutputStream
public java.io.OutputStream getOutputStream() throws java.io.IOException
Returns anOutputStream
that can be used for storing the contents of the file.- Specified by:
getOutputStream
in interfaceFileItem
- Returns:
- An
OutputStream
that can be used for storing the contents of the file. - Throws:
java.io.IOException
- if an error occurs.
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getStoreLocation
public java.io.File getStoreLocation()
Returns theFile
object for theFileItem
's data's temporary location on the disk. Note that forFileItem
s that have their data stored in memory, this method will returnnull
. When handling large files, you can useFile.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.
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finalize
protected void finalize()
Removes the file contents from the temporary storage.- Overrides:
finalize
in classjava.lang.Object
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getTempFile
protected java.io.File getTempFile()
Creates and returns aFile
representing a uniquely named temporary file in the configured repository path. The lifetime of the file is tied to the lifetime of theFileItem
instance; the file will be deleted when the instance is garbage collected.Note: Subclasses that override this method must ensure that they return the same File each time.
- Returns:
- The
File
to be used for temporary storage.
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getUniqueId
private static java.lang.String getUniqueId()
Returns an identifier that is unique within the class loader used to load this class, but does not have random-like appearance.- Returns:
- A String with the non-random looking instance identifier.
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toString
public java.lang.String toString()
Returns a string representation of this object.- Overrides:
toString
in classjava.lang.Object
- Returns:
- a string representation of this object.
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getHeaders
public FileItemHeaders getHeaders()
Returns the file item headers.- Specified by:
getHeaders
in interfaceFileItemHeadersSupport
- Returns:
- The file items headers.
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setHeaders
public void setHeaders(FileItemHeaders pHeaders)
Sets the file item headers.- Specified by:
setHeaders
in interfaceFileItemHeadersSupport
- Parameters:
pHeaders
- The file items headers.
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getDefaultCharset
public java.lang.String getDefaultCharset()
Returns the default charset for use when no explicit charset parameter is provided by the sender.- Returns:
- the default charset
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setDefaultCharset
public void setDefaultCharset(java.lang.String charset)
Sets the default charset for use when no explicit charset parameter is provided by the sender.- Parameters:
charset
- the default charset
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