Class IOUtils


  • public final class IOUtils
    extends Object
    Utility functions
    • Field Detail

      • EMPTY_LINK_OPTIONS

        public static final LinkOption[] EMPTY_LINK_OPTIONS
        Empty array of of type LinkOption.
        Since:
        1.21
    • Method Detail

      • copy

        public static long copy​(InputStream input,
                                OutputStream output)
                         throws IOException
        Copies the content of a InputStream into an OutputStream. Uses a default buffer size of 8024 bytes.
        Parameters:
        input - the InputStream to copy
        output - the target Stream
        Returns:
        the number of bytes copied
        Throws:
        IOException - if an error occurs
      • copy

        public static long copy​(InputStream input,
                                OutputStream output,
                                int buffersize)
                         throws IOException
        Copies the content of a InputStream into an OutputStream
        Parameters:
        input - the InputStream to copy
        output - the target Stream
        buffersize - the buffer size to use, must be bigger than 0
        Returns:
        the number of bytes copied
        Throws:
        IOException - if an error occurs
        IllegalArgumentException - if buffersize is smaller than or equal to 0
      • skip

        public static long skip​(InputStream input,
                                long numToSkip)
                         throws IOException
        Skips the given number of bytes by repeatedly invoking skip on the given input stream if necessary.

        In a case where the stream's skip() method returns 0 before the requested number of bytes has been skip this implementation will fall back to using the read() method.

        This method will only skip less than the requested number of bytes if the end of the input stream has been reached.

        Parameters:
        input - stream to skip bytes in
        numToSkip - the number of bytes to skip
        Returns:
        the number of bytes actually skipped
        Throws:
        IOException - on error
      • read

        public static int read​(File file,
                               byte[] array)
                        throws IOException
        Reads as much from the file as possible to fill the given array.

        This method may invoke read repeatedly to fill the array and only read less bytes than the length of the array if the end of the stream has been reached.

        Parameters:
        file - file to read
        array - buffer to fill
        Returns:
        the number of bytes actually read
        Throws:
        IOException - on error
        Since:
        1.20
      • readFully

        public static int readFully​(InputStream input,
                                    byte[] array)
                             throws IOException
        Reads as much from input as possible to fill the given array.

        This method may invoke read repeatedly to fill the array and only read less bytes than the length of the array if the end of the stream has been reached.

        Parameters:
        input - stream to read from
        array - buffer to fill
        Returns:
        the number of bytes actually read
        Throws:
        IOException - on error
      • readFully

        public static int readFully​(InputStream input,
                                    byte[] array,
                                    int offset,
                                    int len)
                             throws IOException
        Reads as much from input as possible to fill the given array with the given amount of bytes.

        This method may invoke read repeatedly to read the bytes and only read less bytes than the requested length if the end of the stream has been reached.

        Parameters:
        input - stream to read from
        array - buffer to fill
        offset - offset into the buffer to start filling at
        len - of bytes to read
        Returns:
        the number of bytes actually read
        Throws:
        IOException - if an I/O error has occurred
      • readFully

        public static void readFully​(ReadableByteChannel channel,
                                     ByteBuffer b)
                              throws IOException
        Reads b.remaining() bytes from the given channel starting at the current channel's position.

        This method reads repeatedly from the channel until the requested number of bytes are read. This method blocks until the requested number of bytes are read, the end of the channel is detected, or an exception is thrown.

        Parameters:
        channel - the channel to read from
        b - the buffer into which the data is read.
        Throws:
        IOException - - if an I/O error occurs.
        EOFException - - if the channel reaches the end before reading all the bytes.
      • toByteArray

        public static byte[] toByteArray​(InputStream input)
                                  throws IOException
        Gets the contents of an InputStream as a byte[].

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.5
      • closeQuietly

        public static void closeQuietly​(Closeable c)
        Closes the given Closeable and swallows any IOException that may occur.
        Parameters:
        c - Closeable to close, can be null
        Since:
        1.7
      • copy

        public static void copy​(File sourceFile,
                                OutputStream outputStream)
                         throws IOException
        Copies the source file to the given output stream.
        Parameters:
        sourceFile - The file to read.
        outputStream - The output stream to write.
        Throws:
        IOException - if an I/O error occurs when reading or writing.
        Since:
        1.21
      • copyRange

        public static long copyRange​(InputStream input,
                                     long len,
                                     OutputStream output)
                              throws IOException
        Copies part of the content of a InputStream into an OutputStream. Uses a default buffer size of 8024 bytes.
        Parameters:
        input - the InputStream to copy
        output - the target Stream
        len - maximum amount of bytes to copy
        Returns:
        the number of bytes copied
        Throws:
        IOException - if an error occurs
        Since:
        1.21
      • copyRange

        public static long copyRange​(InputStream input,
                                     long len,
                                     OutputStream output,
                                     int buffersize)
                              throws IOException
        Copies part of the content of a InputStream into an OutputStream
        Parameters:
        input - the InputStream to copy
        len - maximum amount of bytes to copy
        output - the target Stream
        buffersize - the buffer size to use, must be bigger than 0
        Returns:
        the number of bytes copied
        Throws:
        IOException - if an error occurs
        IllegalArgumentException - if buffersize is smaller than or equal to 0
        Since:
        1.21
      • readRange

        public static byte[] readRange​(InputStream input,
                                       int len)
                                throws IOException
        Gets part of the contents of an InputStream as a byte[].
        Parameters:
        input - the InputStream to read from
        len - maximum amount of bytes to copy
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.21
      • readRange

        public static byte[] readRange​(ReadableByteChannel input,
                                       int len)
                                throws IOException
        Gets part of the contents of an ReadableByteChannel as a byte[].
        Parameters:
        input - the ReadableByteChannel to read from
        len - maximum amount of bytes to copy
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        1.21