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DataInputStream (Java SE 10 & JDK 10 )

    • Constructor Detail

      • DataInputStream

        public DataInputStream​(InputStream in)

        Creates a DataInputStream that uses the specified underlying InputStream.

        Parameters:
        in - the specified input stream

    • Method Detail

      • read

        public final int read​(byte[] b)
               throws IOException

        Reads some number of bytes from the contained input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

        If b is null, a NullPointerException is thrown. If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

        The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

        The read(b) method has the same effect as: 

         read(b, 0, b.length)
        Overrides:
        read in class FilterInputStream
        Parameters:
        b - the buffer into which the data is read.
        Returns:
        the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
        Throws:
        IOException - if the first byte cannot be read for any reason other than end of file, the stream has been closed and the underlying input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in, InputStream.read(byte[], int, int)

      • read

        public final int read​(byte[] b,
                      int off,
                      int len)
               throws IOException

        Reads up to len bytes of data from the contained input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer.

        This method blocks until input data is available, end of file is detected, or an exception is thrown.

        If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

        The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

        In every case, elements b[0] through b[off] and elements b[off+len] through b[b.length-1] are unaffected.

        Overrides:
        read in class FilterInputStream
        Parameters:
        b - the buffer into which the data is read.
        off - the start offset in the destination array b
        len - the maximum number of bytes read.
        Returns:
        the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
        Throws:
        NullPointerException - If b is null.
        IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off
        IOException - if the first byte cannot be read for any reason other than end of file, the stream has been closed and the underlying input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in, InputStream.read(byte[], int, int)

      • readFully

        public final void readFully​(byte[] b)
                     throws IOException

        See the general contract of the readFully method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readFully in interface DataInput
        Parameters:
        b - the buffer into which the data is read.
        Throws:
        NullPointerException - if b is null.
        EOFException - if this input stream reaches the end before reading all the bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readFully

        public final void readFully​(byte[] b,
                            int off,
                            int len)
                     throws IOException

        See the general contract of the readFully method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readFully in interface DataInput
        Parameters:
        b - the buffer into which the data is read.
        off - the start offset in the data array b.
        len - the number of bytes to read.
        Throws:
        NullPointerException - if b is null.
        IndexOutOfBoundsException - if off is negative, len is negative, or len is greater than b.length - off.
        EOFException - if this input stream reaches the end before reading all the bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • skipBytes

        public final int skipBytes​(int n)
                    throws IOException

        See the general contract of the skipBytes method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        skipBytes in interface DataInput
        Parameters:
        n - the number of bytes to be skipped.
        Returns:
        the actual number of bytes skipped.
        Throws:
        IOException - if the contained input stream does not support seek, or the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.

      • readBoolean

        public final boolean readBoolean()
                          throws IOException

        See the general contract of the readBoolean method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readBoolean in interface DataInput
        Returns:
        the boolean value read.
        Throws:
        EOFException - if this input stream has reached the end.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readByte

        public final byte readByte()
                    throws IOException

        See the general contract of the readByte method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readByte in interface DataInput
        Returns:
        the next byte of this input stream as a signed 8-bit byte.
        Throws:
        EOFException - if this input stream has reached the end.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readUnsignedByte

        public final int readUnsignedByte()
                           throws IOException

        See the general contract of the readUnsignedByte method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readUnsignedByte in interface DataInput
        Returns:
        the next byte of this input stream, interpreted as an unsigned 8-bit number.
        Throws:
        EOFException - if this input stream has reached the end.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readShort

        public final short readShort()
                      throws IOException

        See the general contract of the readShort method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readShort in interface DataInput
        Returns:
        the next two bytes of this input stream, interpreted as a signed 16-bit number.
        Throws:
        EOFException - if this input stream reaches the end before reading two bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readUnsignedShort

        public final int readUnsignedShort()
                            throws IOException

        See the general contract of the readUnsignedShort method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readUnsignedShort in interface DataInput
        Returns:
        the next two bytes of this input stream, interpreted as an unsigned 16-bit integer.
        Throws:
        EOFException - if this input stream reaches the end before reading two bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readChar

        public final char readChar()
                    throws IOException

        See the general contract of the readChar method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readChar in interface DataInput
        Returns:
        the next two bytes of this input stream, interpreted as a char.
        Throws:
        EOFException - if this input stream reaches the end before reading two bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readInt

        public final int readInt()
                  throws IOException

        See the general contract of the readInt method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readInt in interface DataInput
        Returns:
        the next four bytes of this input stream, interpreted as an int.
        Throws:
        EOFException - if this input stream reaches the end before reading four bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readLong

        public final long readLong()
                    throws IOException

        See the general contract of the readLong method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readLong in interface DataInput
        Returns:
        the next eight bytes of this input stream, interpreted as a long.
        Throws:
        EOFException - if this input stream reaches the end before reading eight bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        FilterInputStream.in

      • readFloat

        public final float readFloat()
                      throws IOException

        See the general contract of the readFloat method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readFloat in interface DataInput
        Returns:
        the next four bytes of this input stream, interpreted as a float.
        Throws:
        EOFException - if this input stream reaches the end before reading four bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        readInt(), Float.intBitsToFloat(int)

      • readDouble

        public final double readDouble()
                        throws IOException

        See the general contract of the readDouble method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readDouble in interface DataInput
        Returns:
        the next eight bytes of this input stream, interpreted as a double.
        Throws:
        EOFException - if this input stream reaches the end before reading eight bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        See Also:
        readLong(), Double.longBitsToDouble(long)

      • readUTF

        public final String readUTF()
                     throws IOException

        See the general contract of the readUTF method of DataInput.

        Bytes for this operation are read from the contained input stream.

        Specified by:
        readUTF in interface DataInput
        Returns:
        a Unicode string.
        Throws:
        EOFException - if this input stream reaches the end before reading all the bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        UTFDataFormatException - if the bytes do not represent a valid modified UTF-8 encoding of a string.
        See Also:
        readUTF(java.io.DataInput)

      • readUTF

        public static final String readUTF​(DataInput in)
                            throws IOException

        Reads from the stream in a representation of a Unicode character string encoded in modified UTF-8 format; this string of characters is then returned as a String. The details of the modified UTF-8 representation are exactly the same as for the readUTF method of DataInput.

        Parameters:
        in - a data input stream.
        Returns:
        a Unicode string.
        Throws:
        EOFException - if the input stream reaches the end before all the bytes.
        IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
        UTFDataFormatException - if the bytes do not represent a valid modified UTF-8 encoding of a Unicode string.
        See Also:
        readUnsignedShort()