Package org.apache.commons.fileupload.disk

Class DiskFileItem

  • 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 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.

    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 the DiskFileItemFactory. 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 of File is garbage collected.) This is done by the so-called reaper thread, which is started and stopped automatically by the FileCleaningTracker 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

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String DEFAULT_CHARSET
      Default content charset to be used when no explicit charset parameter is provided by the sender.

    • 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 new DiskFileItem instance.

    • Method Summary

      All 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.
      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 or null if not defined.
      java.lang.String getContentType()
      Returns the content type passed by the agent or null 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 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 charset)
      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.
      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 a FileItem 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.

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • 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

    • Constructor Detail

      • 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 new DiskFileItem instance.
        Parameters:
        fieldName - The name of the form field.
        contentType - The content type passed by the browser or null 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, or null 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.

    • Method Detail

      • 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 agent or null if not defined.
        Specified by:
        getContentType in interface FileItem
        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 or null 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 interface FileItem
        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 use InvalidFileNameException.getName().

      • 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; false otherwise.

      • 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 or null if the data cannot be read

      • 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 uses get() to retrieve the contents of the file.
        Specified by:
        getString in interface FileItem
        Parameters:
        charset - The charset 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. TODO Consider making this method throw UnsupportedEncodingException.
        Specified by:
        getString in interface FileItem
        Returns:
        The contents of the file, as a string.

      • 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.

        Specified by:
        write in interface FileItem
        Parameters:
        file - The File into which the uploaded item 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.
        See Also:
        setFieldName(java.lang.String)

      • 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.
        See Also:
        getFieldName()

      • 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.
        See Also:
        setFormField(boolean)

      • setFormField

        public void setFormField​(boolean state)
        Specifies whether or not a FileItem instance represents a simple form field.
        Specified by:
        setFormField in interface FileItem
        Parameters:
        state - true if the instance represents a simple form field; false if it represents an uploaded file.
        See Also:
        isFormField()

      • 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 contents of the file.
        Throws:
        java.io.IOException - if an error occurs.

      • 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(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.

      • toString

        public java.lang.String toString()
        Returns a string representation of this object.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation of this object.

      • 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

      • 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