Module java.desktop

Class FileImageInputStream

    • Constructor Detail

      • FileImageInputStream

        public FileImageInputStream​(File f)
                             throws FileNotFoundException,
                                    IOException
        Constructs a FileImageInputStream that will read from a given File.

        The file contents must not change between the time this object is constructed and the time of the last call to a read method.

        Parameters:
        f - a File to read from.
        Throws:
        IllegalArgumentException - if f is null.
        SecurityException - if a security manager exists and does not allow read access to the file.
        FileNotFoundException - if f is a directory or cannot be opened for reading for any other reason.
        IOException - if an I/O error occurs.
      • FileImageInputStream

        public FileImageInputStream​(RandomAccessFile raf)
        Constructs a FileImageInputStream that will read from a given RandomAccessFile.

        The file contents must not change between the time this object is constructed and the time of the last call to a read method.

        Parameters:
        raf - a RandomAccessFile to read from.
        Throws:
        IllegalArgumentException - if raf is null.
    • Method Detail

      • read

        public int read​()
                 throws IOException
        Description copied from class: ImageInputStreamImpl
        Reads a single byte from the stream and returns it as an int between 0 and 255. If EOF is reached, -1 is returned.

        Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

        The bit offset within the stream must be reset to zero before the read occurs.

        Specified by:
        read in interface ImageInputStream
        Specified by:
        read in class ImageInputStreamImpl
        Returns:
        the value of the next byte in the stream, or -1 if EOF is reached.
        Throws:
        IOException - if the stream has been closed.
      • read

        public int read​(byte[] b,
                        int off,
                        int len)
                 throws IOException
        Description copied from class: ImageInputStreamImpl
        Reads up to len bytes from the stream, and stores them into b starting at index off. If no bytes can be read because the end of the stream has been reached, -1 is returned.

        The bit offset within the stream must be reset to zero before the read occurs.

        Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

        Specified by:
        read in interface ImageInputStream
        Specified by:
        read in class ImageInputStreamImpl
        Parameters:
        b - an array of bytes to be written to.
        off - the starting position within b to write to.
        len - the maximum number of bytes to read.
        Returns:
        the number of bytes actually read, or -1 to indicate EOF.
        Throws:
        IOException - if an I/O error occurs.
      • length

        public long length​()
        Returns the length of the underlying file, or -1 if it is unknown.
        Specified by:
        length in interface ImageInputStream
        Overrides:
        length in class ImageInputStreamImpl
        Returns:
        the file length as a long, or -1.
      • seek

        public void seek​(long pos)
                  throws IOException
        Description copied from interface: ImageInputStream
        Sets the current stream position to the desired location. The next read will occur at this location. The bit offset is set to 0.

        An IndexOutOfBoundsException will be thrown if pos is smaller than the flushed position (as returned by getflushedPosition).

        It is legal to seek past the end of the file; a java.io.EOFException will be thrown only if a read is performed.

        Specified by:
        seek in interface ImageInputStream
        Overrides:
        seek in class ImageInputStreamImpl
        Parameters:
        pos - a long containing the desired file pointer position.
        Throws:
        IOException - if any other I/O error occurs.
      • close

        public void close​()
                   throws IOException
        Description copied from interface: ImageInputStream
        Closes the stream. Attempts to access a stream that has been closed may result in IOExceptions or incorrect behavior. Calling this method may allow classes implementing this interface to release resources associated with the stream such as memory, disk space, or file descriptors.
        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Specified by:
        close in interface ImageInputStream
        Overrides:
        close in class ImageInputStreamImpl
        Throws:
        IOException - if an I/O error occurs.
      • finalize

        @Deprecated(since="9")
        protected void finalize​()
                         throws Throwable
        Deprecated. The finalize method has been deprecated. Subclasses that override finalize in order to perform cleanup should be modified to use alternative cleanup mechanisms and to remove the overriding finalize method. When overriding the finalize method, its implementation must explicitly ensure that super.finalize() is invoked as described in Object.finalize(). See the specification for Object.finalize() for further information about migration options.
        Finalizes this object prior to garbage collection. The close method is called to close any open input source. This method should not be called from application code.
        Overrides:
        finalize in class ImageInputStreamImpl
        Throws:
        Throwable - if an error occurs during superclass finalization.
        See Also:
        WeakReference, PhantomReference