java.io.InputStream
jgroup.util.InMessage
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java.lang.Object
public final class InMessage
Input stream message optimized to avoid message copying.
| Constructor Summary | |
|---|---|
InMessage()
Default constructor for externalization. |
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InMessage(int payload,
int header,
int trailer)
This constructor builds an empty message subdivided in fragments. |
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InMessage(int payload,
int header,
int trailer,
int size)
This constructor builds a message input stream subdivided in fragments with length header + payload + trailer. |
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InMessage(OutMessage msg)
Construct a InMessage starting from an OutMessage. |
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| Method Summary | |
|---|---|
boolean |
compare(int pos1,
InMessage msg,
int pos2,
int len)
Compares the bytes contained in this InMessage with those contained in another InMessage. |
int |
getByteCount()
Returns the total number of bytes stored in this message output stream. |
int |
getFragmentCount()
Returns the number of fragments composing the message. |
byte[][] |
getFragments()
|
int |
getHeader()
|
int |
getLastPayload()
Returns the length of the payload of the last fragment composing the message. |
int |
getPayload()
Returns the length of the payload field for this message. |
int |
getPosition()
Returns the current position in the message. |
int |
getTrailer()
|
void |
insert(byte[] data,
int blen)
Insert a new fragment in the message whose payload field is blen bytes long. |
void |
mark(int readlimit)
Marks the current position in this input stream. |
boolean |
markSupported()
Tests if this input stream supports the mark and
reset methods. |
int |
read()
Reads the next byte of data from the input stream. |
int |
read(byte[] b)
Reads some number of bytes from the 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 input stream into
an array of bytes. |
boolean |
readBoolean()
Reads one input byte and returns true if that byte is nonzero,
false if that byte is zero. |
byte |
readByte()
Reads and returns one input byte. |
char |
readChar()
Reads an input char and returns the char value. |
double |
readDouble()
Reads eight input bytes and returns a double value. |
void |
readExternal(java.io.ObjectInput in)
Restores the content of this object from the marshalled data contained in the specified input stream. |
float |
readFloat()
Reads four input bytes and returns a float value. |
void |
readFully(byte[] b)
Reads some bytes from an input stream and stores them into the buffer array b. |
void |
readFully(byte[] b,
int off,
int len)
Reads len
bytes from
an input stream. |
int |
readInt()
Reads four input bytes and returns an int value. |
java.lang.String |
readLine()
Reads the next line of text from the input stream. |
long |
readLong()
Reads eight input bytes and returns a long value. |
java.lang.Object |
readObject()
Read and return an object. |
short |
readShort()
Reads two input bytes and returns a short value. |
int |
readUnsignedByte()
Reads one input byte, zero-extends it to type int, and returns
the result, which is therefore in the range
0
through 255. |
int |
readUnsignedShort()
Reads two input bytes and returns an int value in the range 0
through 65535. |
java.lang.String |
readUTF()
Reads in a string that has been encoded using a modified UTF-8 format. |
void |
reset()
Repositions this stream to the position at the time the mark method was last called on this input stream. |
void |
seek(int newpos)
Move the current position in the stream to the specified position. |
long |
skip(long n)
Skips over and discards n bytes of data from this input
stream. |
int |
skipBytes(int n)
Makes an attempt to skip over n bytes
of data from the input
stream, discarding the skipped bytes. |
java.lang.String |
toString()
Returns a string representation of this object |
void |
writeExternal(java.io.ObjectOutput out)
Marshals the content of this object to the specified output stream. |
| Methods inherited from class java.io.InputStream |
|---|
available, close |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
| Methods inherited from interface java.io.ObjectInput |
|---|
available, close |
| Constructor Detail |
|---|
public InMessage(int payload,
int header,
int trailer)
header + payload + trailer.
A IndexOutOfBoundsException is thrown if: payload is negative or equal to zero; header is negative; trailer is negative; size is negative or equal to zero.
public InMessage(int payload,
int header,
int trailer,
int size)
header + payload + trailer.
java.lang.IndexOutOfBoundsException - Raised if payload is negative or equal to zero;
header is negative; trailer is
negative; size is negative or equal to zero.public InMessage(OutMessage msg)
public InMessage()
| Method Detail |
|---|
public void readExternal(java.io.ObjectInput in)
throws java.io.IOException
readExternal in interface java.io.Externalizablein - the stream to be read
java.io.IOException
public void writeExternal(java.io.ObjectOutput out)
throws java.io.IOException
writeExternal in interface java.io.Externalizableout - the stream to be written
java.io.IOExceptionpublic int read()
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.
read in interface java.io.ObjectInputread in class java.io.InputStream-1 if the end of the
stream is reached.
java.io.IOException - if an I/O error occurs.public int read(byte[] b)
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 for class InputStream
has the same effect as:
read(b, 0, b.length)
read in interface java.io.ObjectInputread in class java.io.InputStreamb - the buffer into which the data is read.
-1 is there is no more data because the end of
the stream has been reached.
public int read(byte[] b,
int off,
int len)
len bytes of data from the 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.
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 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 interface java.io.ObjectInputread in class java.io.InputStreamb - the buffer into which the data is read.off - the start offset in array b
at which the data is written.len - the maximum number of bytes to read.
-1 if there is no more data because the end of
the stream has been reached.public long skip(long n)
n bytes of data from this input
stream. The skip method may, for a variety of reasons, end
up skipping over some smaller number of bytes, possibly 0.
This may result from any of a number of conditions; reaching end of file
before n bytes have been skipped is only one possibility.
The actual number of bytes skipped is returned. If n is
negative, no bytes are skipped.
The skip method of InputStream creates a
byte array and then repeatedly reads into it until n bytes
have been read or the end of the stream has been reached. Subclasses are
encouraged to provide a more efficient implementation of this method.
skip in interface java.io.ObjectInputskip in class java.io.InputStreamn - the number of bytes to be skipped.
java.io.IOException - if an I/O error occurs.public void mark(int readlimit)
reset method repositions this stream at the last marked
position so that subsequent reads re-read the same bytes.
The readlimit arguments tells this input stream to
allow that many bytes to be read before the mark position gets
invalidated.
The general contract of mark is that, if the method
markSupported returns true, the stream somehow
remembers all the bytes read after the call to mark and
stands ready to supply those same bytes again if and whenever the method
reset is called. However, the stream is not required to
remember any data at all if more than readlimit bytes are
read from the stream before reset is called.
mark in class java.io.InputStreamreadlimit - not used
public void reset()
throws java.io.IOException
mark method was last called on this input stream.
The general contract of reset is:
markSupported returns
true, then:
mark has not been called since
the stream was created, or the number of bytes read from the stream
since mark was last called is larger than the argument
to mark at that last call, then an
IOException might be thrown.
IOException is not thrown, then the
stream is reset to a state such that all the bytes read since the
most recent call to mark (or since the start of the
file, if mark has not been called) will be resupplied
to subsequent callers of the read method, followed by
any bytes that otherwise would have been the next input data as of
the time of the call to reset. markSupported returns
false, then:
reset may throw an
IOException.
IOException is not thrown, then the stream
is reset to a fixed state that depends on the particular type of the
input stream and how it was created. The bytes that will be supplied
to subsequent callers of the read method depend on the
particular type of the input stream. The method reset for class InputStream
does nothing and always throws an IOException.
reset in class java.io.InputStreamjava.io.IOException - if this stream has not been marked or if the
mark has been invalidated.public boolean markSupported()
mark and
reset methods. The markSupported method of
InputStream returns false.
markSupported in class java.io.InputStreamtrue if this true type supports the mark and reset
method; false otherwise.
public void readFully(byte[] b)
throws java.io.IOException
b. The number of bytes read is equal to
the length of b. This method blocks until one of the following conditions occurs:
b.length bytes of input data are available, in
which case a normal return is made.
EOFException is thrown.
IOException
other than EOFException is thrown.
If b.length is zero, then no bytes are read.
Otherwise, the first byte read is stored into element
b[0], the next one into b[1], and so on.
If an exception is thrown from this method, then it may be that
some but not all bytes of b have been updated with
data from the input stream.
readFully in interface java.io.DataInputb - The buffer into which the data is read.
java.io.EOFException - If this stream reaches the end before reading all the bytes.
java.io.IOException - If an I/O error occurs.
java.lang.NullPointerException - Thrown if b is null.
public void readFully(byte[] b,
int off,
int len)
throws java.io.IOException
len
bytes from
an input stream.
This method blocks until one of the following conditions occurs:
len bytes
of input data are available, in which case
a normal return is made.
EOFException
is thrown.
IOException other
than EOFException is thrown.
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 read. Otherwise, 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.
readFully in interface java.io.DataInputb - the buffer into which the data is read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public int skipBytes(int n)
throws java.io.IOException
n bytes
of data from the input
stream, discarding the skipped bytes. However,
it may skip
over some smaller number of
bytes, possibly zero. This may result from
any of a
number of conditions; reaching
end of file before n bytes
have been skipped is
only one possibility.
This method never throws an EOFException.
The actual
number of bytes skipped is returned.
skipBytes in interface java.io.DataInputn - the number of bytes to be skipped.
n.
java.io.EOFException - if this stream reaches the end before skipping
all the bytes.
java.io.IOException - if an I/O error occurs.
public boolean readBoolean()
throws java.io.IOException
true if that byte is nonzero,
false if that byte is zero.
This method is suitable for reading
the byte written by the writeBoolean
method of interface DataOutput.
readBoolean in interface java.io.DataInputboolean value read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public byte readByte()
throws java.io.IOException
-128 through 127,
inclusive.
This method is suitable for
reading the byte written by the writeByte
method of interface DataOutput.
readByte in interface java.io.DataInputjava.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public int readUnsignedByte()
throws java.io.IOException
int, and returns
the result, which is therefore in the range
0
through 255.
This method is suitable for reading
the byte written by the writeByte
method of interface DataOutput
if the argument to writeByte
was intended to be a value in the range
0 through 255.
readUnsignedByte in interface java.io.DataInputjava.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public short readShort()
throws java.io.IOException
short value. Let a
be the first byte read and b
be the second byte. The value
returned
is:
(short)((a << 8) * | (b & 0xff))
writeShort method of
interface DataOutput.
readShort in interface java.io.DataInputjava.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public int readUnsignedShort()
throws java.io.IOException
int value in the range 0
through 65535. Let a
be the first byte read and
b
be the second byte. The value returned is:
(((a & 0xff) << 8) | (b & 0xff))
writeShort method
of interface DataOutput if
the argument to writeShort
was intended to be a value in the range
0 through 65535.
readUnsignedShort in interface java.io.DataInputjava.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public char readChar()
throws java.io.IOException
char and returns the char value.
A Unicode char is made up of two bytes.
Let a
be the first byte read and b
be the second byte. The value
returned is:
(char)((a << 8) | (b & 0xff))
writeChar method of interface
DataOutput.
readChar in interface java.io.DataInputchar read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public int readInt()
throws java.io.IOException
int value. Let a
be the first byte read, b be
the second byte, c be the third
byte,
and d be the fourth
byte. The value returned is:
(((a & 0xff) << 24) | ((b & 0xff) << 16) |
((c & 0xff) << 8) | (d & 0xff))
This method is suitable
for reading bytes written by the writeInt
method of interface DataOutput.
readInt in interface java.io.DataInputint value read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public long readLong()
throws java.io.IOException
long value. Let a
be the first byte read, b be
the second byte, c be the third
byte, d
be the fourth byte,
e be the fifth byte, f
be the sixth byte, g be the
seventh byte,
and h be the
eighth byte. The value returned is:
(((long)(a & 0xff) << 56) |
((long)(b & 0xff) << 48) |
((long)(c & 0xff) << 40) |
((long)(d & 0xff) << 32) |
((long)(e & 0xff) << 24) |
((long)(f & 0xff) << 16) |
((long)(g & 0xff) << 8) |
((long)(h & 0xff)))
This method is suitable
for reading bytes written by the writeLong
method of interface DataOutput.
readLong in interface java.io.DataInputlong value read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public float readFloat()
throws java.io.IOException
float value. It does this
by first constructing an int
value in exactly the manner
of the readInt
method, then converting this int
value to a float in
exactly the manner of the method Float.intBitsToFloat.
This method is suitable for reading
bytes written by the writeFloat
method of interface DataOutput.
readFloat in interface java.io.DataInputfloat value read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public double readDouble()
throws java.io.IOException
double value. It does this
by first constructing a long
value in exactly the manner
of the readlong
method, then converting this long
value to a double in exactly
the manner of the method Double.longBitsToDouble.
This method is suitable for reading
bytes written by the writeDouble
method of interface DataOutput.
readDouble in interface java.io.DataInputdouble value read.
java.io.EOFException - if this stream reaches the end before reading
all the bytes.
java.io.IOException - if an I/O error occurs.
public java.lang.String readLine()
throws java.io.IOException
String. Note
that because this
method processes bytes,
it does not support input of the full Unicode
character set.
If end of file is encountered
before even one byte can be read, then null
is returned. Otherwise, each byte that is
read is converted to type char
by zero-extension. If the character '\n'
is encountered, it is discarded and reading
ceases. If the character '\r'
is encountered, it is discarded and, if
the following byte converts to the
character '\n', then that is
discarded also; reading then ceases. If
end of file is encountered before either
of the characters '\n' and
'\r' is encountered, reading
ceases. Once reading has ceased, a String
is returned that contains all the characters
read and not discarded, taken in order.
Note that every character in this string
will have a value less than \u0100,
that is, (char)256.
readLine in interface java.io.DataInputjava.io.IOException - if an I/O error occurs.
public java.lang.String readUTF()
throws java.io.IOException
readUTF
is that it reads a representation of a Unicode
character string encoded in Java modified
UTF-8 format; this string of characters
is then returned as a String.
First, two bytes are read and used to
construct an unsigned 16-bit integer in
exactly the manner of the readUnsignedShort
method . This integer value is called the
UTF length and specifies the number
of additional bytes to be read. These bytes
are then converted to characters by considering
them in groups. The length of each group
is computed from the value of the first
byte of the group. The byte following a
group, if any, is the first byte of the
next group.
If the first byte of a group
matches the bit pattern 0xxxxxxx
(where x means "may be 0
or 1"), then the group consists
of just that byte. The byte is zero-extended
to form a character.
If the first byte
of a group matches the bit pattern 110xxxxx,
then the group consists of that byte a
and a second byte b. If there
is no byte b (because byte
a was the last of the bytes
to be read), or if byte b does
not match the bit pattern 10xxxxxx,
then a UTFDataFormatException
is thrown. Otherwise, the group is converted
to the character:
(char)(((a& 0x1F) << 6) | (b & 0x3F))
1110xxxx,
then the group consists of that byte a
and two more bytes b and c.
If there is no byte c (because
byte a was one of the last
two of the bytes to be read), or either
byte b or byte c
does not match the bit pattern 10xxxxxx,
then a UTFDataFormatException
is thrown. Otherwise, the group is converted
to the character:
(char)(((a & 0x0F) << 12) | ((b & 0x3F) << 6) | (c & 0x3F))
1111xxxx or the pattern
10xxxxxx, then a UTFDataFormatException
is thrown.
If end of file is encountered
at any time during this entire process,
then an EOFException is thrown.
After every group has been converted to
a character by this process, the characters
are gathered, in the same order in which
their corresponding groups were read from
the input stream, to form a String,
which is returned.
The writeUTF
method of interface DataOutput
may be used to write data that is suitable
for reading by this method.
readUTF in interface java.io.DataInputjava.io.EOFException - if this stream reaches the end
before reading all the bytes.
java.io.IOException - if an I/O error occurs.
java.io.UTFDataFormatException - if the bytes do not represent a
valid UTF-8 encoding of a string.
public java.lang.Object readObject()
throws java.lang.ClassNotFoundException,
java.io.IOException
readObject in interface java.io.ObjectInputjava.lang.ClassNotFoundException - If the class of a serialized
object cannot be found.
java.io.IOException - If any of the usual Input/Output
related exceptions occur.public void seek(int newpos)
position.
java.lang.IndexOutOfBoundsException - Raised if the new position in the message exceeds the maximum
length.
public boolean compare(int pos1,
InMessage msg,
int pos2,
int len)
pos1 - starting position in this messagemsg - the meessage to be comparedpos2 - starting position in len - the number of bytes to be compared
public void insert(byte[] data,
int blen)
public int getByteCount()
public int getPosition()
public int getFragmentCount()
public byte[][] getFragments()
public int getPayload()
public int getLastPayload()
public int getHeader()
public int getTrailer()
public java.lang.String toString()
toString in class java.lang.Object
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