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Added in API level 1

BufferedWriter

public class BufferedWriter
extends Writer

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


Wraps an existing Writer and buffers the output. Expensive interaction with the underlying reader is minimized, since most (smaller) requests can be satisfied by accessing the buffer alone. The drawback is that some extra space is required to hold the buffer and that copying takes place when filling that buffer, but this is usually outweighed by the performance benefits.

A typical application pattern for the class looks like this:

 BufferedWriter buf = new BufferedWriter(new FileWriter("file.java"));
 

See also:

Summary

Inherited fields

From class java.io.Writer

Public constructors

BufferedWriter(Writer out)

Constructs a new BufferedWriter, providing out with a buffer of 8192 chars.

BufferedWriter(Writer out, int size)

Constructs a new BufferedWriter, providing out with size chars of buffer.

Public methods

void close()

Closes this writer.

void flush()

Flushes this writer.

void newLine()

Writes a newline to this writer.

void write(char[] buffer, int offset, int count)

Writes count characters starting at offset in buffer to this writer.

void write(String str, int offset, int count)

Writes count characters starting at offset in str to this writer.

void write(int oneChar)

Writes the character oneChar to this writer.

Inherited methods

From class java.io.Writer
From class java.lang.Object
From interface java.lang.Appendable
From interface java.io.Closeable
From interface java.io.Flushable
From interface java.lang.AutoCloseable

Public constructors

BufferedWriter

Added in API level 1
BufferedWriter (Writer out)

Constructs a new BufferedWriter, providing out with a buffer of 8192 chars.

Parameters
out Writer: the Writer the buffer writes to.

BufferedWriter

Added in API level 1
BufferedWriter (Writer out, 
                int size)

Constructs a new BufferedWriter, providing out with size chars of buffer.

Parameters
out Writer: the OutputStream the buffer writes to.
size int: the size of buffer in chars.
Throws
IllegalArgumentException if size <= 0.

Public methods

close

Added in API level 1
void close ()

Closes this writer. The contents of the buffer are flushed, the target writer is closed, and the buffer is released. Only the first invocation of close has any effect.

Throws
IOException if an error occurs while closing this writer.

flush

Added in API level 1
void flush ()

Flushes this writer. The contents of the buffer are committed to the target writer and it is then flushed.

Throws
IOException if an error occurs while flushing this writer.

newLine

Added in API level 1
void newLine ()

Writes a newline to this writer. On Android, this is "\n". The target writer may or may not be flushed when a newline is written.

Throws
IOException if an error occurs attempting to write to this writer.

write

Added in API level 1
void write (char[] buffer, 
                int offset, 
                int count)

Writes count characters starting at offset in buffer to this writer. If count is greater than this writer's buffer, then the buffer is flushed and the characters are written directly to the target writer.

Parameters
buffer char: the array containing characters to write.
offset int: the start position in buffer for retrieving characters.
count int: the maximum number of characters to write.
Throws
IndexOutOfBoundsException if offset < 0 or count < 0, or if offset + count is greater than the size of buffer.
IOException if this writer is closed or another I/O error occurs.

write

Added in API level 1
void write (String str, 
                int offset, 
                int count)

Writes count characters starting at offset in str to this writer. If count is greater than this writer's buffer, then this writer is flushed and the remaining characters are written directly to the target writer. If count is negative no characters are written to the buffer. This differs from the behavior of the superclass.

Parameters
str String: the non-null String containing characters to write.
offset int: the start position in str for retrieving characters.
count int: maximum number of characters to write.
Throws
IOException if this writer has already been closed or another I/O error occurs.
IndexOutOfBoundsException if offset < 0 or offset + count is greater than the length of str.

write

Added in API level 1
void write (int oneChar)

Writes the character oneChar to this writer. If the buffer gets full by writing this character, this writer is flushed. Only the lower two bytes of the integer oneChar are written.

Parameters
oneChar int: the character to write.
Throws
IOException if this writer is closed or another I/O error occurs.
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