java.lang.Object | |
↳ | java.io.Writer |
Known Direct Subclasses |
Known Indirect Subclasses |
The base class for all writers. A writer is a means of writing data to a
target in a character-wise manner. Most output streams expect the
flush()
method to be called before closing the stream, to ensure all
data is actually written out.
This abstract class does not provide a fully working implementation, so it
needs to be subclassed, and at least the
write(char[], int, int)
,
close()
and
flush()
methods needs to be overridden.
Overriding some of the non-abstract methods is also often advised, since it
might result in higher efficiency.
Many specialized readers for purposes like reading from a file already exist in this package.
Fields | |||||||||||
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lock | The object used to synchronize access to the writer. |
Protected Constructors | |||||||||||
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Constructs a new
Writer
with
this
as the object used to
synchronize critical sections.
|
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|
Constructs a new
Writer
with
lock
used to synchronize
critical sections.
|
Public Methods | |||||||||||
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|
Appends the character sequence
csq
to the target.
|
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|
Appends a subsequence of the character sequence
csq
to the
target.
|
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|
Appends the character
c
to the target.
|
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|
Closes this writer.
|
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|
Flushes this writer.
|
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|
Writes the entire character buffer
buf
to the target.
|
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|
Writes the characters from the specified string to the target.
|
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|
Writes
count
characters starting at
offset
in
buf
to the target.
|
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|
Writes
count
characters from
str
starting at
offset
to the target.
|
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|
Writes one character to the target.
|
[Expand]
Inherited Methods
|
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From class
java.lang.Object
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From interface
java.io.Closeable
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From interface
java.io.Flushable
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From interface
java.lang.Appendable
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From interface
java.lang.AutoCloseable
|
Constructs a new
Writer
with
this
as the object used to
synchronize critical sections.
Constructs a new
Writer
with
lock
used to synchronize
critical sections.
lock |
the
Object
used to synchronize critical sections.
|
---|
NullPointerException |
if
lock
is
null
.
|
---|
Appends the character sequence
csq
to the target. This method
works the same way as
Writer.write(csq.toString())
. If
csq
is
null
, then the string "null" is written to the target
stream.
csq | the character sequence appended to the target. |
---|
IOException | if this writer is closed or another I/O error occurs. |
---|
Appends a subsequence of the character sequence
csq
to the
target. This method works the same way as
Writer.writer(csq.subsequence(start, end).toString())
. If
csq
is
null
, then the specified subsequence of the string "null"
will be written to the target.
csq | the character sequence appended to the target. |
---|---|
start | the index of the first char in the character sequence appended to the target. |
end | the index of the character following the last character of the subsequence appended to the target. |
IOException | if this writer is closed or another I/O error occurs. |
---|---|
IndexOutOfBoundsException |
if
start > end
,
start < 0
,
end < 0
or
either
start
or
end
are greater or equal than
the length of
csq
.
|
Appends the character
c
to the target. This method works the same
way as
write(int)
.
c | the character to append to the target stream. |
---|
IOException | if this writer is closed or another I/O error occurs. |
---|
Closes this writer. Implementations of this method should free any resources associated with the writer.
IOException | if an error occurs while closing this writer. |
---|
Flushes this writer. Implementations of this method should ensure that all buffered characters are written to the target.
IOException | if an error occurs while flushing this writer. |
---|
Writes the entire character buffer
buf
to the target.
buf | the non-null array containing characters to write. |
---|
IOException | if this writer is closed or another I/O error occurs. |
---|
Writes the characters from the specified string to the target.
str | the non-null string containing the characters to write. |
---|
IOException | if this writer is closed or another I/O error occurs. |
---|
Writes
count
characters starting at
offset
in
buf
to the target.
buf | the non-null character array to write. |
---|---|
offset |
the index of the first character in
buf
to write.
|
count | the maximum number of characters to write. |
IndexOutOfBoundsException |
if
offset < 0
or
count < 0
, or if
offset + count
is greater than the size of
buf
.
|
---|---|
IOException | if this writer is closed or another I/O error occurs. |
Writes
count
characters from
str
starting at
offset
to the target.
str | the non-null string containing the characters to write. |
---|---|
offset |
the index of the first character in
str
to write.
|
count |
the number of characters from
str
to write.
|
IOException | if this writer is closed or another I/O error occurs. |
---|---|
IndexOutOfBoundsException |
if
offset < 0
or
count < 0
, or if
offset + count
is greater than the length of
str
.
|
Writes one character to the target. Only the two least significant bytes
of the integer
oneChar
are written.
oneChar | the character to write to the target. |
---|
IOException | if this writer is closed or another I/O error occurs. |
---|