Added in API level 1

Summary: Inherited Fields | Ctors | Methods | Inherited Methods

BufferedWriter

public class BufferedWriter
extends Writer

java.lang.Object
↳	java.io.Writer
	↳	java.io.BufferedWriter

Writes text to a character-output stream, buffering characters so as to provide for the efficient writing of single characters, arrays, and strings.

The buffer size may be specified, or the default size may be accepted. The default is large enough for most purposes.

A newLine() method is provided, which uses the platform's own notion of line separator as defined by the system property line.separator. Not all platforms use the newline character ('\n') to terminate lines. Calling this method to terminate each output line is therefore preferred to writing a newline character directly.

In general, a Writer sends its output immediately to the underlying character or byte stream. Unless prompt output is required, it is advisable to wrap a BufferedWriter around any Writer whose write() operations may be costly, such as FileWriters and OutputStreamWriters. For example,

 PrintWriter out
   = new PrintWriter(new BufferedWriter(new FileWriter("foo.out")));

will buffer the PrintWriter's output to the file. Without buffering, each invocation of a print() method would cause characters to be converted into bytes that would then be written immediately to the file, which can be very inefficient.

See also:

Summary

Inherited fields

From class java.io.Writer


    protected
    
    
    Object

lock

The object used to synchronize operations on this stream.

Public constructors
`BufferedWriter(Writer out)` Creates a buffered character-output stream that uses a default-sized output buffer.
`BufferedWriter(Writer out, int sz)` Creates a new buffered character-output stream that uses an output buffer of the given size.

Public methods
`void`	`close()` Closes the stream, flushing it first.
`void`	`flush()` Flushes the stream.
`void`	`newLine()` Writes a line separator.
`void`	`write(int c)` Writes a single character.
`void`	`write(String s, int off, int len)` Writes a portion of a String.
`void`	`write(char[] cbuf, int off, int len)` Writes a portion of an array of characters.

Inherited methods

From class


        
          java.io.Writer

`Writer`	`append(char c)` Appends the specified character to this writer.
`Writer`	`append(CharSequence csq, int start, int end)` Appends a subsequence of the specified character sequence to this writer.
`Writer`	`append(CharSequence csq)` Appends the specified character sequence to this writer.
`abstract void`	`close()` Closes the stream, flushing it first.
`abstract void`	`flush()` Flushes the stream.
`static Writer`	`nullWriter()` Returns a new `Writer` which discards all characters.
`void`	`write(String str)` Writes a string.
`void`	`write(int c)` Writes a single character.
`void`	`write(String str, int off, int len)` Writes a portion of a string.
`abstract void`	`write(char[] cbuf, int off, int len)` Writes a portion of an array of characters.
`void`	`write(char[] cbuf)` Writes an array of characters.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.lang.Appendable

`abstract Appendable`	`append(char c)` Appends the specified character to this `Appendable`.
`abstract Appendable`	`append(CharSequence csq, int start, int end)` Appends a subsequence of the specified character sequence to this `Appendable`.
`abstract Appendable`	`append(CharSequence csq)` Appends the specified character sequence to this `Appendable`.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.io.Flushable


      flush()

Flushes this stream by writing any buffered output to the underlying stream.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Public constructors

BufferedWriter

Added in API level 1

public BufferedWriter (Writer out)

Creates a buffered character-output stream that uses a default-sized output buffer.

Parameters
`out`	`Writer`: A Writer

BufferedWriter

Added in API level 1

public BufferedWriter (Writer out, 
                int sz)

Creates a new buffered character-output stream that uses an output buffer of the given size.

Parameters
`out`	`Writer`: A Writer
`sz`	`int`: Output-buffer size, a positive integer

Throws
`IllegalArgumentException`	If `sz <= 0`

Public methods

close

Added in API level 1

public void close ()

Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect.

Throws
`IOException`

flush

Added in API level 1

public void flush ()

Flushes the stream.

Throws
`IOException`	If an I/O error occurs

newLine

Added in API level 1

public void newLine ()

Writes a line separator. The line separator string is defined by the system property line.separator, and is not necessarily a single newline ('\n') character.

Throws
`IOException`	If an I/O error occurs

write

Added in API level 1

public void write (int c)

Writes a single character.

Parameters
`c`	`int`: int specifying a character to be written

Throws
`IOException`	If an I/O error occurs

write

Added in API level 1

public void write (String s, 
                int off, 
                int len)

Writes a portion of a String.

Implementation Requirements:

While the specification of this method in the superclass recommends that an IndexOutOfBoundsException be thrown if len is negative or off + len is negative, the implementation in this class does not throw such an exception in these cases but instead simply writes no characters.

Parameters
`s`	`String`: String to be written
`off`	`int`: Offset from which to start reading characters
`len`	`int`: Number of characters to be written

Throws
`IndexOutOfBoundsException`	If `off` is negative, or `off + len` is greater than the length of the given string
`IOException`	If an I/O error occurs

write

Added in API level 1

public void write (char[] cbuf, 
                int off, 
                int len)

Writes a portion of an array of characters.

Ordinarily this method stores characters from the given array into this stream's buffer, flushing the buffer to the underlying stream as needed. If the requested length is at least as large as the buffer, however, then this method will flush the buffer and write the characters directly to the underlying stream. Thus redundant BufferedWriters will not copy data unnecessarily.

Parameters
`cbuf`	`char`: A character array
`off`	`int`: Offset from which to start reading characters
`len`	`int`: Number of characters to write

Throws
`IndexOutOfBoundsException`	If `off` is negative, or `len` is negative, or `off + len` is negative or greater than the length of the given array
`IOException`	If an I/O error occurs