java.io.OutputStream
java.io.ObjectOutputStream.BlockDataOutputStream
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java.lang.Object
Buffered output stream with two modes: in default mode, outputs data in same format as DataOutputStream; in "block data" mode, outputs data bracketed by block data markers (see object serialization specification for details).
| Field Summary | |
private boolean |
blkmode
block data mode |
private byte[] |
buf
buffer for writing general/block data |
private char[] |
cbuf
char buffer for fast string writes |
private static int |
CHAR_BUF_SIZE
(tunable) length of char buffer (for writing strings) |
private DataOutputStream |
dout
loopback stream (for data writes that span data blocks) |
private byte[] |
hbuf
buffer for writing block data headers |
private static int |
MAX_BLOCK_SIZE
maximum data block length |
private static int |
MAX_HEADER_SIZE
maximum data block header length |
private OutputStream |
out
underlying output stream |
private int |
pos
current offset into buf |
| Constructor Summary | |
(package private) |
ObjectOutputStream.BlockDataOutputStream(OutputStream out)
Creates new BlockDataOutputStream on top of given underlying stream. |
| Method Summary | |
void |
close()
Closes this output stream and releases any system resources associated with this stream. |
(package private) void |
drain()
Writes all buffered data from this stream to the underlying stream, but does not flush underlying stream. |
void |
flush()
Flushes this output stream and forces any buffered output bytes to be written out. |
(package private) boolean |
getBlockDataMode()
Returns true if the stream is currently in block data mode, false otherwise. |
(package private) long |
getUTFLength(String s)
Returns the length in bytes of the UTF encoding of the given string. |
(package private) boolean |
setBlockDataMode(boolean mode)
Sets block data mode to the given mode (true == on, false == off) and returns the previous mode value. |
void |
write(byte[] b)
Writes to the output stream all the bytes in array b.
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void |
write(byte[] b,
int off,
int len)
Writes len bytes from array
b, in order, to
the output stream. |
(package private) void |
write(byte[] b,
int off,
int len,
boolean copy)
Writes specified span of byte values from given array. |
void |
write(int b)
Writes to the output stream the eight low-order bits of the argument b.
|
private void |
writeBlockHeader(int len)
Writes block data header. |
void |
writeBoolean(boolean v)
Writes a boolean value to this output stream.
|
(package private) void |
writeBooleans(boolean[] v,
int off,
int len)
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void |
writeByte(int v)
Writes to the output stream the eight low- order bits of the argument v.
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void |
writeBytes(String s)
Writes a string to the output stream. |
void |
writeChar(int v)
Writes a char value, wich
is comprised of two bytes, to the
output stream.
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(package private) void |
writeChars(char[] v,
int off,
int len)
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void |
writeChars(String s)
Writes every character in the string s,
to the output stream, in order,
two bytes per character. |
void |
writeDouble(double v)
Writes a double value,
which is comprised of eight bytes, to the output stream.
|
(package private) void |
writeDoubles(double[] v,
int off,
int len)
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void |
writeFloat(float v)
Writes a float value,
which is comprised of four bytes, to the output stream.
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(package private) void |
writeFloats(float[] v,
int off,
int len)
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void |
writeInt(int v)
Writes an int value, which is
comprised of four bytes, to the output stream.
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(package private) void |
writeInts(int[] v,
int off,
int len)
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void |
writeLong(long v)
Writes a long value, which is
comprised of eight bytes, to the output stream.
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(package private) void |
writeLongs(long[] v,
int off,
int len)
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(package private) void |
writeLongUTF(String s)
Writes given string in "long" UTF format. |
(package private) void |
writeLongUTF(String s,
long utflen)
Writes given string in "long" UTF format, where the UTF encoding length of the string is already known. |
void |
writeShort(int v)
Writes two bytes to the output stream to represent the value of the argument. |
(package private) void |
writeShorts(short[] v,
int off,
int len)
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void |
writeUTF(String s)
Writes two bytes of length information to the output stream, followed by the Java modified UTF representation of every character in the string s.
|
(package private) void |
writeUTF(String s,
long utflen)
Writes the given string in UTF format. |
private void |
writeUTFBody(String s)
Writes the "body" (i.e., the UTF representation minus the 2-byte or 8-byte length header) of the UTF encoding for the given string. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
private static final int MAX_BLOCK_SIZE
private static final int MAX_HEADER_SIZE
private static final int CHAR_BUF_SIZE
private final byte[] buf
private final byte[] hbuf
private final char[] cbuf
private boolean blkmode
private int pos
private final OutputStream out
private final DataOutputStream dout
| Constructor Detail |
ObjectOutputStream.BlockDataOutputStream(OutputStream out)
| Method Detail |
boolean setBlockDataMode(boolean mode)
throws IOException
IOExceptionboolean getBlockDataMode()
public void write(int b)
throws IOException
DataOutputb.
The 24 high-order bits of b
are ignored.
write in interface DataOutputwrite in class OutputStreamb - the byte.
IOException - if an I/O error occurs. In particular,
an IOException may be thrown if the
output stream has been closed.
public void write(byte[] b)
throws IOException
DataOutputb.
If b is null,
a NullPointerException is thrown.
If b.length is zero, then
no bytes are written. Otherwise, the byte
b[0] is written first, then
b[1], and so on; the last byte
written is b[b.length-1].
write in interface DataOutputwrite in class OutputStreamb - the data.
IOException - if an I/O error occurs.OutputStream.write(byte[], int, int)
public void write(byte[] b,
int off,
int len)
throws IOException
DataOutputlen bytes from array
b, in order, to
the output stream. If b
is null, a NullPointerException
is thrown. If off is negative,
or len is negative, or off+len
is greater than the length of the array
b, then an IndexOutOfBoundsException
is thrown. If len is zero,
then no bytes are written. Otherwise, the
byte b[off] is written first,
then b[off+1], and so on; the
last byte written is b[off+len-1].
write in interface DataOutputwrite in class OutputStreamb - the data.off - the start offset in the data.len - the number of bytes to write.
IOException - if an I/O error occurs. In particular,
an IOException is thrown if the output
stream is closed.
public void flush()
throws IOException
OutputStreamflush is
that calling it is an indication that, if any bytes previously
written have been buffered by the implementation of the output
stream, such bytes should immediately be written to their
intended destination.
The flush method of OutputStream does nothing.
flush in class OutputStreamIOException - if an I/O error occurs.
public void close()
throws IOException
OutputStreamclose
is that it closes the output stream. A closed stream cannot perform
output operations and cannot be reopened.
The close method of OutputStream does nothing.
close in class OutputStreamIOException - if an I/O error occurs.
void write(byte[] b,
int off,
int len,
boolean copy)
throws IOException
IOException
void drain()
throws IOException
IOException
private void writeBlockHeader(int len)
throws IOException
IOException
public void writeBoolean(boolean v)
throws IOException
DataOutputboolean value to this output stream.
If the argument v
is true, the value (byte)1
is written; if v is false,
the value (byte)0 is written.
The byte written by this method may
be read by the readBoolean
method of interface DataInput,
which will then return a boolean
equal to v.
writeBoolean in interface DataOutputv - the boolean to be written.
IOException - if an I/O error occurs.
public void writeByte(int v)
throws IOException
DataOutputv.
The 24 high-order bits of v
are ignored. (This means that writeByte
does exactly the same thing as write
for an integer argument.) The byte written
by this method may be read by the readByte
method of interface DataInput,
which will then return a byte
equal to (byte)v.
writeByte in interface DataOutputv - the byte value to be written.
IOException - if an I/O error occurs.
public void writeChar(int v)
throws IOException
DataOutputchar value, wich
is comprised of two bytes, to the
output stream.
The byte values to be written, in the order
shown, are:
(byte)(0xff & (v >> 8))
(byte)(0xff & v)
The bytes written by this method may be
read by the readChar method
of interface DataInput , which
will then return a char equal
to (char)v.
writeChar in interface DataOutputv - the char value to be written.
IOException - if an I/O error occurs.
public void writeShort(int v)
throws IOException
DataOutput
(byte)(0xff & (v >> 8))
(byte)(0xff & v)
The bytes written by this method may be
read by the readShort method
of interface DataInput , which
will then return a short equal
to (short)v.
writeShort in interface DataOutputv - the short value to be written.
IOException - if an I/O error occurs.
public void writeInt(int v)
throws IOException
DataOutputint value, which is
comprised of four bytes, to the output stream.
The byte values to be written, in the order
shown, are:
(byte)(0xff & (v >> 24))
(byte)(0xff & (v >> 16))
(byte)(0xff & (v >> 8))
(byte)(0xff & v)
The bytes written by this method may be read
by the readInt method of interface
DataInput , which will then
return an int equal to v.
writeInt in interface DataOutputv - the int value to be written.
IOException - if an I/O error occurs.
public void writeFloat(float v)
throws IOException
DataOutputfloat value,
which is comprised of four bytes, to the output stream.
It does this as if it first converts this
float value to an int
in exactly the manner of the Float.floatToIntBits
method and then writes the int
value in exactly the manner of the writeInt
method. The bytes written by this method
may be read by the readFloat
method of interface DataInput,
which will then return a float
equal to v.
writeFloat in interface DataOutputv - the float value to be written.
IOException - if an I/O error occurs.
public void writeLong(long v)
throws IOException
DataOutputlong value, which is
comprised of eight bytes, to the output stream.
The byte values to be written, in the order
shown, are:
(byte)(0xff & (v >> 56))
(byte)(0xff & (v >> 48))
(byte)(0xff & (v >> 40))
(byte)(0xff & (v >> 32))
(byte)(0xff & (v >> 24))
(byte)(0xff & (v >> 16))
(byte)(0xff & (v >> 8))
(byte)(0xff & v)
The bytes written by this method may be
read by the readLong method
of interface DataInput , which
will then return a long equal
to v.
writeLong in interface DataOutputv - the long value to be written.
IOException - if an I/O error occurs.
public void writeDouble(double v)
throws IOException
DataOutputdouble value,
which is comprised of eight bytes, to the output stream.
It does this as if it first converts this
double value to a long
in exactly the manner of the Double.doubleToLongBits
method and then writes the long
value in exactly the manner of the writeLong
method. The bytes written by this method
may be read by the readDouble
method of interface DataInput,
which will then return a double
equal to v.
writeDouble in interface DataOutputv - the double value to be written.
IOException - if an I/O error occurs.
public void writeBytes(String s)
throws IOException
DataOutputs, taken in order, one byte
is written to the output stream. If
s is null, a NullPointerException
is thrown. If s.length
is zero, then no bytes are written. Otherwise,
the character s[0] is written
first, then s[1], and so on;
the last character written is s[s.length-1].
For each character, one byte is written,
the low-order byte, in exactly the manner
of the writeByte method . The
high-order eight bits of each character
in the string are ignored.
writeBytes in interface DataOutputs - the string of bytes to be written.
IOException - if an I/O error occurs.
public void writeChars(String s)
throws IOException
DataOutputs,
to the output stream, in order,
two bytes per character. If s
is null, a NullPointerException
is thrown. If s.length
is zero, then no characters are written.
Otherwise, the character s[0]
is written first, then s[1],
and so on; the last character written is
s[s.length-1]. For each character,
two bytes are actually written, high-order
byte first, in exactly the manner of the
writeChar method.
writeChars in interface DataOutputs - the string value to be written.
IOException - if an I/O error occurs.
public void writeUTF(String s)
throws IOException
DataOutputs.
If s is null,
a NullPointerException is thrown.
Each character in the string s
is converted to a group of one, two, or
three bytes, depending on the value of the
character.
If a character c
is in the range \u0001 through
\u007f, it is represented
by one byte:
(byte)c
If a character c is \u0000
or is in the range \u0080
through \u07ff, then it is
represented by two bytes, to be written
in the order shown:
(byte)(0xc0 | (0x1f & (c >> 6)))
(byte)(0x80 | (0x3f & c))
If a character
c is in the range \u0800
through uffff, then it is
represented by three bytes, to be written
in the order shown:
(byte)(0xe0 | (0x0f & (c >> 12)))
(byte)(0x80 | (0x3f & (c >> 6)))
(byte)(0x80 | (0x3f & c))
First,
the total number of bytes needed to represent
all the characters of s is
calculated. If this number is larger than
65535, then a UTFDataFormatException
is thrown. Otherwise, this length is written
to the output stream in exactly the manner
of the writeShort method;
after this, the one-, two-, or three-byte
representation of each character in the
string s is written.
The
bytes written by this method may be read
by the readUTF method of interface
DataInput , which will then
return a String equal to s.
writeUTF in interface DataOutputs - the string value to be written.
IOException - if an I/O error occurs.
void writeBooleans(boolean[] v,
int off,
int len)
throws IOException
IOException
void writeChars(char[] v,
int off,
int len)
throws IOException
IOException
void writeShorts(short[] v,
int off,
int len)
throws IOException
IOException
void writeInts(int[] v,
int off,
int len)
throws IOException
IOException
void writeFloats(float[] v,
int off,
int len)
throws IOException
IOException
void writeLongs(long[] v,
int off,
int len)
throws IOException
IOException
void writeDoubles(double[] v,
int off,
int len)
throws IOException
IOExceptionlong getUTFLength(String s)
void writeUTF(String s,
long utflen)
throws IOException
IOException
void writeLongUTF(String s)
throws IOException
IOException
void writeLongUTF(String s,
long utflen)
throws IOException
IOException
private void writeUTFBody(String s)
throws IOException
IOException
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