public class DataInputStream extends FilterInputStream implements DataInput
DataInputStream is not necessarily safe for multithreaded access. Thread safety is optional and is the responsibility of users of methods in this class.
DataOutputStreamin| Constructor and Description |
|---|
DataInputStream(InputStream in)
Creates a DataInputStream that uses the specified
underlying InputStream.
|
| Modifier and Type | Method and Description |
|---|---|
int |
read(byte[] b)
Reads some number of bytes from the contained input stream and
stores them into the buffer array
b. |
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes of data from the contained
input stream into an array of bytes. |
boolean |
readBoolean()
See the general contract of the
readBoolean
method of DataInput. |
byte |
readByte()
See the general contract of the
readByte
method of DataInput. |
char |
readChar()
See the general contract of the
readChar
method of DataInput. |
double |
readDouble()
See the general contract of the
readDouble
method of DataInput. |
float |
readFloat()
See the general contract of the
readFloat
method of DataInput. |
void |
readFully(byte[] b)
See the general contract of the
readFully
method of DataInput. |
void |
readFully(byte[] b,
int off,
int len)
See the general contract of the
readFully
method of DataInput. |
int |
readInt()
See the general contract of the
readInt
method of DataInput. |
String |
readLine()
Deprecated.
This method does not properly convert bytes to characters.
As of JDK 1.1, the preferred way to read lines of text is via the
BufferedReader.readLine() method. Programs that use the
DataInputStream class to read lines can be converted to use
the BufferedReader class by replacing code of the form:
with:
|
long |
readLong()
See the general contract of the
readLong
method of DataInput. |
short |
readShort()
See the general contract of the
readShort
method of DataInput. |
int |
readUnsignedByte()
See the general contract of the
readUnsignedByte
method of DataInput. |
int |
readUnsignedShort()
See the general contract of the
readUnsignedShort
method of DataInput. |
String |
readUTF()
See the general contract of the
readUTF
method of DataInput. |
static String |
readUTF(DataInput in)
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. |
int |
skipBytes(int n)
See the general contract of the
skipBytes
method of DataInput. |
available, close, mark, markSupported, read, reset, skippublic DataInputStream(InputStream in)
in - the specified input streampublic final int read(byte[] b)
throws IOException
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)
read in class FilterInputStreamb - the buffer into which the data is read.-1 if there is no more data because the end
of the stream has been reached.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.FilterInputStream.in,
InputStream.read(byte[], int, int)public final int read(byte[] b,
int off,
int len)
throws IOException
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.
read in class FilterInputStreamb - the buffer into which the data is read.off - the start offset in the destination array blen - the maximum number of bytes read.-1 if there is no more data because the end
of the stream has been reached.NullPointerException - If b is null.IndexOutOfBoundsException - If off is negative,
len is negative, or len is greater than
b.length - offIOException - 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.FilterInputStream.in,
InputStream.read(byte[], int, int)public final void readFully(byte[] b)
throws IOException
readFully
method of DataInput.
Bytes for this operation are read from the contained input stream.
readFully in interface DataInputb - the buffer into which the data is read.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.FilterInputStream.inpublic final void readFully(byte[] b,
int off,
int len)
throws IOException
readFully
method of DataInput.
Bytes for this operation are read from the contained input stream.
readFully in interface DataInputb - the buffer into which the data is read.off - the start offset of the data.len - the number of bytes to read.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.FilterInputStream.inpublic final int skipBytes(int n)
throws IOException
skipBytes
method of DataInput.
Bytes for this operation are read from the contained input stream.
skipBytes in interface DataInputn - the number of bytes to be skipped.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.public final boolean readBoolean()
throws IOException
readBoolean
method of DataInput.
Bytes for this operation are read from the contained input stream.
readBoolean in interface DataInputboolean value read.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.FilterInputStream.inpublic final byte readByte()
throws IOException
readByte
method of DataInput.
Bytes for this operation are read from the contained input stream.
readByte in interface DataInputbyte.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.FilterInputStream.inpublic final int readUnsignedByte()
throws IOException
readUnsignedByte
method of DataInput.
Bytes for this operation are read from the contained input stream.
readUnsignedByte in interface DataInputEOFException - 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.FilterInputStream.inpublic final short readShort()
throws IOException
readShort
method of DataInput.
Bytes for this operation are read from the contained input stream.
readShort in interface DataInputEOFException - 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.FilterInputStream.inpublic final int readUnsignedShort()
throws IOException
readUnsignedShort
method of DataInput.
Bytes for this operation are read from the contained input stream.
readUnsignedShort in interface DataInputEOFException - 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.FilterInputStream.inpublic final char readChar()
throws IOException
readChar
method of DataInput.
Bytes for this operation are read from the contained input stream.
readChar in interface DataInputchar.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.FilterInputStream.inpublic final int readInt()
throws IOException
readInt
method of DataInput.
Bytes for this operation are read from the contained input stream.
readInt in interface DataInputint.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.FilterInputStream.inpublic final long readLong()
throws IOException
readLong
method of DataInput.
Bytes for this operation are read from the contained input stream.
readLong in interface DataInputlong.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.FilterInputStream.inpublic final float readFloat()
throws IOException
readFloat
method of DataInput.
Bytes for this operation are read from the contained input stream.
readFloat in interface DataInputfloat.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.readInt(),
Float.intBitsToFloat(int)public final double readDouble()
throws IOException
readDouble
method of DataInput.
Bytes for this operation are read from the contained input stream.
readDouble in interface DataInputdouble.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.readLong(),
Double.longBitsToDouble(long)@Deprecated public final String readLine() throws IOException
BufferedReader.readLine() method. Programs that use the
DataInputStream class to read lines can be converted to use
the BufferedReader class by replacing code of the form:
DataInputStream d = new DataInputStream(in);
with:
BufferedReader d
= new BufferedReader(new InputStreamReader(in));
readLine
method of DataInput.
Bytes for this operation are read from the contained input stream.
readLine in interface DataInputIOException - if an I/O error occurs.BufferedReader.readLine(),
FilterInputStream.inpublic final String readUTF() throws IOException
readUTF
method of DataInput.
Bytes for this operation are read from the contained input stream.
readUTF in interface DataInputEOFException - 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.readUTF(java.io.DataInput)public static final String readUTF(DataInput in) throws IOException
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.in - a data input stream.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.readUnsignedShort() Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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