javax.jnlp

Interface FileContents

public interface FileContents

FileContents objects encapsulate the name and contents of a file. An implementation of this class is used by the FileOpenService, FileSaveService, and PersistenceService.

The FileContents implementation returned by PersistenceService.get(java.net.URL), FileOpenService, and FileSaveService should never truncate a file if the maximum file length is set to be less that the current file length.

Since:

1.4.2

See Also:

FileOpenService, FileSaveService

Method Summary

Modifier and Type	Method and Description
boolean	canRead() Returns whether the file can be read.
boolean	canWrite() Returns whether the file can be written to.
java.io.InputStream	getInputStream() Gets an InputStream from the file.
long	getLength() Gets the length of the file.
long	getMaxLength() Gets the maximum file length for the file, as set by the creator of this object.
java.lang.String	getName() Gets the file name as a String.
java.io.OutputStream	getOutputStream(boolean overwrite) Gets an OutputStream to the file.
JNLPRandomAccessFile	getRandomAccessFile(java.lang.String mode) Returns a JNLPRandomAccessFile representing a random access interface to the file's contents.
long	setMaxLength(long maxlength) Sets the maximum file length for the file.

Method Detail

getName

java.lang.String getName()
                  throws java.io.IOException

Gets the file name as a String.

Returns:

a string containing the file name.

Throws:

java.io.IOException - if an I/O exception occurs.

getInputStream

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

Gets an InputStream from the file.

Returns:

an InputStream to the file.

Throws:

java.io.IOException - if an I/O exception occurs.

getOutputStream

java.io.OutputStream getOutputStream(boolean overwrite)
                              throws java.io.IOException

Gets an OutputStream to the file. A JNLP client may implement this interface to return an OutputStream subclass which restricts the amount of data that can be written to the stream.

Returns:

an OutputStream from the file.

Throws:

java.io.IOException - if an I/O exception occurs.

getLength

long getLength()
        throws java.io.IOException

Gets the length of the file.

Returns:

the length of the file as a long.

Throws:

java.io.IOException - if an I/O exception occurs.

canRead

boolean canRead()
         throws java.io.IOException

Returns whether the file can be read.

Returns:

true if the file can be read, false otherwise.

Throws:

java.io.IOException - if an I/O exception occurs.

canWrite

boolean canWrite()
          throws java.io.IOException

Returns whether the file can be written to.

Returns:

true if the file can be read, false otherwise.

Throws:

java.io.IOException - if an I/O exception occurs.

getRandomAccessFile

JNLPRandomAccessFile getRandomAccessFile(java.lang.String mode)
                                  throws java.io.IOException

Returns a JNLPRandomAccessFile representing a random access interface to the file's contents. The mode argument must either be equal to "r" or "rw", indicating the file is to be opened for input only or for both input and output, respectively. An IllegalArgumentException will be thrown if the mode is not equal to "r" or "rw".

Parameters:

mode - the access mode.

Returns:

a JNLPRandomAccessFile.

Throws:

java.io.IOException - if an I/O exception occurs.

getMaxLength

long getMaxLength()
           throws java.io.IOException

Gets the maximum file length for the file, as set by the creator of this object.

Returns:

the maximum length of the file.

Throws:

java.io.IOException - if an I/O exception occurs.

setMaxLength

long setMaxLength(long maxlength)
           throws java.io.IOException

Sets the maximum file length for the file. A JNLP client may enforce restrictions on setting the maximum file length. A JNLP client should not truncate a file if the maximum file length is set that is less than the current file size, but it also should not allow further writes to that file.

Parameters:

maxlength - the requested new maximum file length.

Returns:

the maximum file length that was granted.

Throws:

java.io.IOException - if an I/O exception occurs.