Java compact1, compact2, compact3 java.io Class Writer（JDK8）

Field Detail

• lock

  protected Object lock

  The object used to synchronize operations on this stream. For efficiency, a character-stream object may use an object other than itself to protect critical sections. A subclass should therefore use the object in this field rather than this or a synchronized method.

Constructor Detail

• Writer

  protected Writer()

  Creates a new character-stream writer whose critical sections will synchronize on the writer itself.

• Writer

  protected Writer(Object lock)

  Creates a new character-stream writer whose critical sections will synchronize on the given object.

  Parameters:

  lock - Object to synchronize on

Method Detail

• write

  public void write(int c)
             throws IOException

  Writes a single character. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored.

  Subclasses that intend to support efficient single-character output should override this method.

  Parameters:

  c - int specifying a character to be written

  Throws:

  IOException - If an I/O error occurs

• write

  public void write(char[] cbuf)
             throws IOException

  Writes an array of characters.

  Parameters:

  cbuf - Array of characters to be written

  Throws:

  IOException - If an I/O error occurs

• write

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

  Writes a portion of an array of characters.

  Parameters:

  cbuf - Array of characters

  off - Offset from which to start writing characters

  len - Number of characters to write

  Throws:

  IOException - If an I/O error occurs

• write

  public void write(String str)
             throws IOException

  Writes a string.

  Parameters:

  str - String to be written

  Throws:

  IOException - If an I/O error occurs

• write

  public void write(String str,
                    int off,
                    int len)
             throws IOException

  Writes a portion of a string.

  Parameters:

  str - A String

  off - Offset from which to start writing characters

  len - 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 string

  IOException - If an I/O error occurs

• append

  public Writer append(CharSequence csq)
                throws IOException

  Appends the specified character sequence to this writer.

  An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

       out.write(csq.toString()) 

  Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

  Specified by:

  append in interface Appendable

  Parameters:

  csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.

  Returns:

  This writer

  Throws:

  IOException - If an I/O error occurs

  Since:

  1.5

• append

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

  Appends a subsequence of the specified character sequence to this writer. Appendable.

  An invocation of this method of the form out.append(csq, start, end) when csq is not null behaves in exactly the same way as the invocation

       out.write(csq.subSequence(start, end).toString()) 

  Specified by:

  append in interface Appendable

  Parameters:

  csq - The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".

  start - The index of the first character in the subsequence

  end - The index of the character following the last character in the subsequence

  Returns:

  This writer

  Throws:

  IndexOutOfBoundsException - If start or end are negative, start is greater than end, or end is greater than csq.length()

  IOException - If an I/O error occurs

  Since:

  1.5

• append

  public Writer append(char c)
                throws IOException

  Appends the specified character to this writer.

  An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation

       out.write(c) 

  Specified by:

  append in interface Appendable

  Parameters:

  c - The 16-bit character to append

  Returns:

  This writer

  Throws:

  IOException - If an I/O error occurs

  Since:

  1.5

• flush

  public abstract void flush()
                      throws IOException

  Flushes the stream. If the stream has saved any characters from the various write() methods in a buffer, write them immediately to their intended destination. Then, if that destination is another character or byte stream, flush it. Thus one flush() invocation will flush all the buffers in a chain of Writers and OutputStreams.

  If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.

  Specified by:

  flush in interface Flushable

  Throws:

  IOException - If an I/O error occurs

• close

  public abstract void close()
                      throws IOException

  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.

  Specified by:

  close in interface Closeable

  Specified by:

  close in interface AutoCloseable

  Throws:

  IOException - If an I/O error occurs