ByteArrayInputStream
contains
an internal buffer that contains bytes that
may be read from the stream. An internal
counter keeps track of the next byte to
be supplied by the read
method.
Closing a ByteArrayInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.
ByteArrayInputStream
so that it uses buf
as its
buffer array.
The buffer array is not copied.
The initial value of pos
is 0
and the initial value
of count
is the length of
buf
.ByteArrayInputStream
that uses buf
as its
buffer array. The initial value of pos
is offset
and the initial value
of count
is the minimum of offset+length
and buf.length
.
The buffer array is not copied. The buffer's mark is
set to the specified offset.count - pos
,
which is the number of bytes remaining to be read from the input buffer.
The equals
method implements an equivalence relation
on non-null object references:
x
, x.equals(x)
should return
true
.
x
and y
, x.equals(y)
should return true
if and only if
y.equals(x)
returns true
.
x
, y
, and z
, if
x.equals(y)
returns true
and
y.equals(z)
returns true
, then
x.equals(z)
should return true
.
x
and y
, multiple invocations of
x.equals(y) consistently return true
or consistently return false
, provided no
information used in equals
comparisons on the
objects is modified.
x
,
x.equals(null)
should return false
.
The equals method for class Object
implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x
and
y
, this method returns true
if and only
if x
and y
refer to the same object
(x == y
has the value true
).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
java.util.Hashtable
.
The general contract of hashCode
is:
hashCode
method on each of
the two objects must produce the same integer result.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
If no mark has been set, then the value of the mark is the offset passed to the constructor (or 0 if the offset was not supplied).
Note: The readAheadLimit
for this class
has no meaning.
InputStream
supports mark/reset. The
markSupported
method of ByteArrayInputStream
always returns true
.wait
methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized
statement
that synchronizes on the object.
Class,
by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait
methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
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 read
method
cannot block.
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.
If the first byte cannot be read for any reason other than end of
file, then an IOException
is thrown. In particular, an
IOException
is thrown if the input stream has been closed.
The read(b)
method for class InputStream
has the same effect as:
read(b, 0, b.length)
len
bytes of data into an array of bytes
from this input stream.
If pos
equals count
,
then -1
is returned to indicate
end of file. Otherwise, the number k
of bytes read is equal to the smaller of
len
and count-pos
.
If k
is positive, then bytes
buf[pos]
through buf[pos+k-1]
are copied into b[off]
through
b[off+k-1]
in the manner performed
by System.arraycopy
. The
value k
is added into pos
and k
is returned.
This read
method cannot block.
n
bytes of input from this input stream. Fewer
bytes might be skipped if the end of the input stream is reached.
The actual number k
of bytes to be skipped is equal to the smaller
of n
and count-pos
.
The value k
is added into pos
and k
is returned.toString
method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@
', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify
method or the
notifyAll
method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) { while (<condition does not hold>) obj.wait(); ... // Perform action appropriate to condition }This method should only be called by a thread that is the owner of this object's monitor. See the
notify
method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) { while (<condition does not hold>) obj.wait(timeout); ... // Perform action appropriate to condition }(For more information on this topic, see Section 3.2.3 in Doug Lea's "Concurrent Programming in Java (Second Edition)" (Addison-Wesley, 2000), or Item 50 in Joshua Bloch's "Effective Java Programming Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify
method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait
method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify
method
or the notifyAll
method.
timeout
milliseconds plus nanos
nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) { while (<condition does not hold>) obj.wait(timeout, nanos); ... // Perform action appropriate to condition }This method should only be called by a thread that is the owner of this object's monitor. See the
notify
method for a
description of the ways in which a thread can become the owner of
a monitor.