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public abstract class

Writer

extends Object
implements Closeable Flushable Appendable
java.lang.Object
   ↳ java.io.Writer
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

Writer is an Abstract class for writing Character Streams. Subclasses of writer must implement the methods write(char[], int, int), close() and flush().

See Also

Summary

Fields
protected Object lock The object used to synchronize access to the writer.
Protected Constructors
Writer()
Constructs a new character stream Writer using this as the Object to synchronize critical regions around.
Writer(Object lock)
Constructs a new character stream Writer using lock as the Object to synchronize critical regions around.
Public Methods
Writer append(CharSequence csq)
Append a CharSequence csq to the Writer.
Writer append(CharSequence csq, int start, int end)
Append a subsequence of a CharSequence csq to the Writer.
Writer append(char c)
Append a char cto the Writer.
abstract void close()
Close this Writer.
abstract void flush()
Flush this Writer.
abstract void write(char[] buf, int offset, int count)
Writes count characters starting at offset in buf to this Writer.
void write(String str, int offset, int count)
Writes count number of characters starting at offset from the String str to this Writer.
void write(int oneChar)
Writes the specified character oneChar to this Writer.
void write(char[] buf)
Writes the entire character buffer buf to this Writer.
void write(String str)
Writes the characters from the String str to this Writer.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.io.Closeable
From interface java.io.Flushable
From interface java.lang.Appendable

Fields

protected Object lock

The object used to synchronize access to the writer.

Protected Constructors

protected Writer ()

Constructs a new character stream Writer using this as the Object to synchronize critical regions around.

protected Writer (Object lock)

Constructs a new character stream Writer using lock as the Object to synchronize critical regions around.

Parameters
lock the Object to synchronize critical regions around.

Public Methods

public Writer append (CharSequence csq)

Append a CharSequence csq to the Writer. The Writer.append(csq) works the same way as Writer.write(csq.toString()). If csq is null, then "null" will be substituted for csq.

Parameters
csq The CharSequence appended to the Writer.
Returns
  • The Writer.
Throws
IOException If any IOException raises during the procedure.

public Writer append (CharSequence csq, int start, int end)

Append a subsequence of a CharSequence csq to the Writer. The first char and the last char of the subsequnce is specified by the parameter start and end. The Writer.append(csq) works the same way as Writer.write (csqcsq.subSequence(start,end).toString). If csq is null, then "null" will be substituted for csq.

Parameters
csq The CharSequence appended to the Writaer.
start The index of the first char in the CharSequence appended to the Writer.
end The index of the char after the last one in the CharSequence appended to the Writer.
Returns
  • The Writer.
Throws
IndexOutOfBoundsException If start is less than end, end is greater than the length of the CharSequence, or start or end is negative.
IOException If any IOException raises during the procedure.

public Writer append (char c)

Append a char cto the Writer. The Writer.append(c) works the same as Writer.write(c).

Parameters
c The character appended to the Writer.
Returns
  • The Writer.
Throws
IOException If any IOException raises during the procedure.

public abstract void close ()

Close this Writer. This must be implemented by any concrete subclasses. The implementation should free any resources associated with the Writer.

Throws
IOException If an error occurs attempting to close this Writer.

public abstract void flush ()

Flush this Writer. This must be implemented by any concrete subclasses. The implementation should ensure all buffered characters are written out.

Throws
IOException If an error occurs attempting to flush this Writer.

public abstract void write (char[] buf, int offset, int count)

Writes count characters starting at offset in buf to this Writer. This abstract method must be implemented by concrete subclasses.

Parameters
buf the non-null array containing characters to write.
offset offset in buf to retrieve characters
count maximum number of characters to write
Throws
IOException If this Writer has already been closed or some other IOException occurs.
ArrayIndexOutOfBoundsException If offset or count are outside of bounds.

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

Writes count number of characters starting at offset from the String str to this Writer.

Parameters
str the non-null String containing the characters to write.
offset the starting point to retrieve characters.
count the number of characters to retrieve and write.
Throws
IOException If this Writer has already been closed or some other IOException occurs.
ArrayIndexOutOfBoundsException If offset or count are outside of bounds.

public void write (int oneChar)

Writes the specified character oneChar to this Writer. This implementation writes the low order two bytes of oneChar to the Stream.

Parameters
oneChar The character to write
Throws
IOException If this Writer has already been closed or some other IOException occurs.

public void write (char[] buf)

Writes the entire character buffer buf to this Writer.

Parameters
buf the non-null array containing characters to write.
Throws
IOException If this Writer has already been closed or some other IOException occurs.

public void write (String str)

Writes the characters from the String str to this Writer.

Parameters
str the non-null String containing the characters to write.
Throws
IOException If this Writer has already been closed or some other IOException occurs.