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| java.lang.Object
 java.io.InputStream
java.io.DataInputStream
| DataInputStream | | public class DataInputStream extends InputStream implements DataInput(Code) | | A data input stream lets an application read primitive Java data
types from an underlying input stream in a machine-independent
way. An application uses a data output stream to write data that
can later be read by a data input stream.
version:
12/17/01 (CLDC 1.1)
See Also: java.io.DataOutputStream
since:
JDK1.0, CLDC 1.0 |
| Constructor Summary | |
| public | DataInputStream(InputStream in)
Creates a DataInputStream
and saves its argument, the input stream
in, for later use. |
| Method Summary | |
| public int | available()
Returns the number of bytes that can be read from this input
stream without blocking. | | public void | close()
Closes this input stream and releases any system resources
associated with the stream. | | public synchronized void | mark(int readlimit)
Marks the current position in this input stream. | | public boolean | markSupported()
Tests if this input stream supports the mark
and reset methods. | | public int | read()
Reads the next byte of data from this input stream. | | final public int | read(byte b)
See the general contract of the read
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
b - the buffer into which the data is read. | | final public int | read(byte b, int off, int len)
Reads up to len bytes of data from this input stream
into an array of bytes. | | final public boolean | readBoolean()
See the general contract of the readBoolean
method of DataInput. | | final public byte | readByte()
See the general contract of the readByte
method of DataInput. | | final public char | readChar()
See the general contract of the readChar
method of DataInput. | | final public double | readDouble()
See the general contract of the readDouble
method of DataInput. | | final public float | readFloat()
See the general contract of the readFloat
method of DataInput. | | final public void | readFully(byte b)
See the general contract of the readFully
method of DataInput. | | final public void | readFully(byte b, int off, int len)
See the general contract of the readFully
method of DataInput. | | final public int | readInt()
See the general contract of the readInt
method of DataInput. | | final public long | readLong()
See the general contract of the readLong
method of DataInput. | | final public short | readShort()
See the general contract of the readShort
method of DataInput. | | final public String | readUTF()
See the general contract of the readUTF
method of DataInput. | | final public static String | readUTF(DataInput in)
Reads from the
stream in a representation
of a Unicode character string encoded in
Java 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. | | final public int | readUnsignedByte()
See the general contract of the readUnsignedByte
method of DataInput. | | final public int | readUnsignedShort()
See the general contract of the readUnsignedShort
method of DataInput. | | public synchronized void | reset()
Repositions this stream to the position at the time the
mark method was last called on this input stream.
This method
simply performs in.reset().
Stream marks are intended to be used in
situations where you need to read ahead a little to see what's in
the stream. | | public long | skip(long n)
Skips over and discards n bytes of data from the
input stream. | | final public int | skipBytes(int n)
See the general contract of the skipBytes
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
n - the number of bytes to be skipped. |
| DataInputStream | | public DataInputStream(InputStream in)(Code) | | Creates a DataInputStream
and saves its argument, the input stream
in, for later use.
Parameters:
in - the input stream. |
| available | | public int available() throws IOException(Code) | | Returns the number of bytes that can be read from this input
stream without blocking.
This method simply performs in.available() and
returns the result.
the number of bytes that can be read from the input streamwithout blocking.
exception:
IOException - if an I/O error occurs. |
| close | | public void close() throws IOException(Code) | | Closes this input stream and releases any system resources
associated with the stream.
This
method simply performs in.close().
exception:
IOException - if an I/O error occurs. |
| mark | | public synchronized void mark(int readlimit)(Code) | | Marks the current position in this input stream. A subsequent
call to the reset method repositions this stream at
the last marked position so that subsequent reads re-read the same bytes.
The readlimit argument tells this input stream to
allow that many bytes to be read before the mark position gets
invalidated.
This method simply performs in.mark(readlimit).
Parameters:
readlimit - the maximum limit of bytes that can be read beforethe mark position becomes invalid. |
| markSupported | | public boolean markSupported()(Code) | | Tests if this input stream supports the mark
and reset methods.
This method
simply performs in.markSupported().
true if this stream type supports themark and reset method;false otherwise. |
| read | | public int read() throws IOException(Code) | | Reads the next byte of data from this input stream. The value
byte is returned as an int in the range
0 to 255. If no byte is available
because the end of the stream has been reached, the value
-1 is returned. This method blocks until input data
is available, the end of the stream is detected, or an exception
is thrown.
This method
simply performs in.read() and returns the result.
the next byte of data, or -1 if the end of thestream is reached.
exception:
IOException - if an I/O error occurs. |
| read | | final public int read(byte b) throws IOException(Code) | | See the general contract of the read
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
b - the buffer into which the data is read. the total number of bytes read into the buffer, or-1 if there is no more data because the endof the stream has been reached.
exception:
IOException - if an I/O error occurs.
See Also: java.io.InputStream.read(byte[]intint) |
| read | | final public int read(byte b, int off, int len) throws IOException(Code) | | Reads up to len bytes of data from this input stream
into an array of bytes. This method blocks until some input is
available.
This method simply performs in.read(b, off, len)
and returns the result.
Parameters:
b - the buffer into which the data is read.
Parameters:
off - the start offset of the data.
Parameters:
len - the maximum number of bytes read. the total number of bytes read into the buffer, or-1 if there is no more data because the end ofthe stream has been reached.
exception:
IOException - if an I/O error occurs. |
| readBoolean | | final public boolean readBoolean() throws IOException(Code) | | See the general contract of the readBoolean
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the boolean value read.
exception:
EOFException - if this input stream has reached the end.
exception:
IOException - if an I/O error occurs. |
| readByte | | final public byte readByte() throws IOException(Code) | | See the general contract of the readByte
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next byte of this input stream as a signed 8-bitbyte.
exception:
EOFException - if this input stream has reached the end.
exception:
IOException - if an I/O error occurs. |
| readChar | | final public char readChar() throws IOException(Code) | | See the general contract of the readChar
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next two bytes of this input stream as a Unicodecharacter.
exception:
EOFException - if this input stream reaches the end beforereading two bytes.
exception:
IOException - if an I/O error occurs. |
| readFully | | final public void readFully(byte b) throws IOException(Code) | | See the general contract of the readFully
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
b - the buffer into which the data is read.
exception:
EOFException - if this input stream reaches the end beforereading all the bytes.
exception:
IOException - if an I/O error occurs. |
| readFully | | final public void readFully(byte b, int off, int len) throws IOException(Code) | | See the general contract of the readFully
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
b - the buffer into which the data is read.
Parameters:
off - the start offset of the data.
Parameters:
len - the number of bytes to read.
exception:
EOFException - if this input stream reaches the end beforereading all the bytes.
exception:
IOException - if an I/O error occurs. |
| readInt | | final public int readInt() throws IOException(Code) | | See the general contract of the readInt
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next four bytes of this input stream, interpreted as anint.
exception:
EOFException - if this input stream reaches the end beforereading four bytes.
exception:
IOException - if an I/O error occurs. |
| readLong | | final public long readLong() throws IOException(Code) | | See the general contract of the readLong
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next eight bytes of this input stream, interpreted as along.
exception:
EOFException - if this input stream reaches the end beforereading eight bytes.
exception:
IOException - if an I/O error occurs. |
| readShort | | final public short readShort() throws IOException(Code) | | See the general contract of the readShort
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next two bytes of this input stream, interpreted as asigned 16-bit number.
exception:
EOFException - if this input stream reaches the end beforereading two bytes.
exception:
IOException - if an I/O error occurs. |
| readUTF | | final public static String readUTF(DataInput in) throws IOException(Code) | | Reads from the
stream in a representation
of a Unicode character string encoded in
Java 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. a Unicode string.
exception:
EOFException - if the input stream reaches the endbefore all the bytes.
exception:
IOException - if an I/O error occurs.
exception:
UTFDataFormatException - if the bytes do not represent avalid UTF-8 encoding of a Unicode string.
See Also: java.io.DataInputStream.readUnsignedShort |
| readUnsignedByte | | final public int readUnsignedByte() throws IOException(Code) | | See the general contract of the readUnsignedByte
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next byte of this input stream, interpreted as anunsigned 8-bit number.
exception:
EOFException - if this input stream has reached the end.
exception:
IOException - if an I/O error occurs. |
| readUnsignedShort | | final public int readUnsignedShort() throws IOException(Code) | | See the general contract of the readUnsignedShort
method of DataInput.
Bytes for this operation are read from the contained
input stream.
the next two bytes of this input stream, interpreted as anunsigned 16-bit integer.
exception:
EOFException - if this input stream reaches the end beforereading two bytes.
exception:
IOException - if an I/O error occurs. |
| reset | | public synchronized void reset() throws IOException(Code) | | Repositions this stream to the position at the time the
mark method was last called on this input stream.
This method
simply performs in.reset().
Stream marks are intended to be used in
situations where you need to read ahead a little to see what's in
the stream. Often this is most easily done by invoking some
general parser. If the stream is of the type handled by the
parse, it just chugs along happily. If the stream is not of
that type, the parser should toss an exception when it fails.
If this happens within readlimit bytes, it allows the outer
code to reset the stream and try another parser.
exception:
IOException - if the stream has not been marked or if themark has been invalidated. |
| skip | | public long skip(long n) throws IOException(Code) | | Skips over and discards n bytes of data from the
input stream. The skip method may, for a variety of
reasons, end up skipping over some smaller number of bytes,
possibly 0. The actual number of bytes skipped is
returned.
This method
simply performs in.skip(n).
Parameters:
n - the number of bytes to be skipped. the actual number of bytes skipped.
exception:
IOException - if an I/O error occurs. |
| skipBytes | | final public int skipBytes(int n) throws IOException(Code) | | See the general contract of the skipBytes
method of DataInput.
Bytes for this operation are read from the contained
input stream.
Parameters:
n - the number of bytes to be skipped. the actual number of bytes skipped.
exception:
IOException - if an I/O error occurs. |
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