Movatterモバイル変換

Class Writer

java.lang.Object
- java.io.Writer

All Implemented Interfaces:
Closeable,Flushable,Appendable,AutoCloseable
Direct Known Subclasses:
BufferedWriter,CharArrayWriter,FilterWriter,OutputStreamWriter,PipedWriter,PrintWriter,StringWriter
```
public abstract classWriterextendsObjectimplementsAppendable,Closeable,Flushable
```
Abstract class for writing to character streams. The only methods that a subclass must implement are write(char[], int, int), flush(), and close(). Most subclasses, however, will override some of the methods defined here in order to provide higher efficiency, additional functionality, or both.
Since:
1.1
See Also:
BufferedWriter,CharArrayWriter,FilterWriter,OutputStreamWriter,FileWriter,PipedWriter,PrintWriter,StringWriter,Reader

Field Summary
Fields
Modifier and Type Field Description
protectedObject lock
The object used to synchronize operations on this stream.

Fields
Modifier and Type	Field	Description
`protectedObject`	`lock`	The object used to synchronize operations on this stream.

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`Writer()`	Creates a new character-stream writer whose critical sections will synchronize on the writer itself.
`protected`	`Writer(Object lock)`	Creates a new character-stream writer whose critical sections will synchronize on the given object.

Method Summary

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

Methods declared in class java.lang.Object
clone,equals,finalize,getClass,hashCode,notify,notifyAll,toString,wait,wait,wait

- 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 thanthis 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
  - nullWriter
```
public static Writer nullWriter()
```
    Returns a newWriter which discards all characters. The returned stream is initially open. The stream is closed by calling theclose() method. Subsequent calls toclose() have no effect.
    While the stream is open, theappend(char), append(CharSequence),append(CharSequence, int, int),flush(),write(int),write(char[]), andwrite(char[], int, int) methods do nothing. After the stream has been closed, these methods all throwIOException.
    Theobject used to synchronize operations on the returnedWriter is not specified.
    Returns:
    aWriter which discards all characters
    Since:
    11
  - write
```
public void write(int c)           throwsIOException
```
    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)           throwsIOException
```
    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)                    throwsIOException
```
    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:
    IndexOutOfBoundsException - Implementations should throw this exception ifoff is negative, orlen is negative, oroff + len is negative or greater than the length of the given array
    IOException - If an I/O error occurs
  - write
```
public void write(String str)           throwsIOException
```
    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)           throwsIOException
```
    Writes a portion of a string.
    Implementation Requirements:
    The implementation in this class throws anIndexOutOfBoundsException for the indicated conditions; overriding methods may choose to do otherwise.
    Parameters:
    str - A String
    off - Offset from which to start writing characters
    len - Number of characters to write
    Throws:
    IndexOutOfBoundsException - Implementations should throw this exception ifoff is negative, orlen is negative, oroff + 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)              throwsIOException
```
    Appends the specified character sequence to this writer.
    An invocation of this method of the formout.append(csq) behaves in exactly the same way as the invocation
    out.write(csq.toString())
    Depending on the specification oftoString for the character sequencecsq, the entire sequence may not be appended. For instance, invoking thetoString 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. Ifcsq isnull, 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)              throwsIOException
```
    Appends a subsequence of the specified character sequence to this writer.Appendable.
    An invocation of this method of the formout.append(csq, start, end) whencsq is notnull 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. Ifcsq isnull, then characters will be appended as ifcsq 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 - Ifstart orend are negative,start is greater thanend, orend is greater thancsq.length()
    IOException - If an I/O error occurs
    Since:
    1.5
  - append
```
public Writer append(char c)              throwsIOException
```
    Appends the specified character to this writer.
    An invocation of this method of the formout.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()                    throwsIOException
```
    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()                    throwsIOException
```
    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 AutoCloseable
    Specified by:
    close in interface Closeable
    Throws:
    IOException - If an I/O error occurs

Movatterモバイル変換

Class Writer

Field Summary

Constructor Summary

Method Summary

Methods declared in class java.lang.Object

Field Detail

lock

Constructor Detail

Writer

Writer

Method Detail

nullWriter

write

write

write

write

write

append

append

append

flush

close