Writer

java.lang.Object
- java.io.Writer

所有已实现的接口:

Closeable, Flushable, Appendable, AutoCloseable

直接已知子类:

BufferedWriter, CharArrayWriter, FilterWriter, OutputStreamWriter, PipedWriter, PrintWriter, StringWriter
```
public abstract class Writer
extends Object
implements Appendable, 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.

从以下版本开始:

JDK1.1

另请参阅:

Writer, BufferedWriter, CharArrayWriter, FilterWriter, OutputStreamWriter, FileWriter, PipedWriter, PrintWriter, StringWriter, Reader

字段概要

字段
限定符和类型字段说明

protected Object lock
The object used to synchronize operations on this stream.

字段
限定符和类型	字段	说明
`protected Object`	`lock`	The object used to synchronize operations on this stream.

构造器概要

构造器
限定符	构造器	说明
`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.

方法概要

所有方法实例方法抽象方法具体方法
限定符和类型	方法	说明
`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.
`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.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - 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.
- 构造器详细资料
  - 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.
    
    参数:
    
    lock - Object to synchronize on
- 方法详细资料
  - 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.
    
    参数:
    
    c - int specifying a character to be written
    
    抛出:
    
    IOException - If an I/O error occurs
  - write
```
public void write(char[] cbuf)
           throws IOException
```
    Writes an array of characters.
    
    参数:
    
    cbuf - Array of characters to be written
    
    抛出:
    
    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.
    
    参数:
    
    cbuf - Array of characters
    
    off - Offset from which to start writing characters
    
    len - Number of characters to write
    
    抛出:
    
    IOException - If an I/O error occurs
  - write
```
public void write(String str)
           throws IOException
```
    Writes a string.
    
    参数:
    
    str - String to be written
    
    抛出:
    
    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.
    
    参数:
    
    str - A String
    
    off - Offset from which to start writing characters
    
    len - Number of characters to write
    
    抛出:
    
    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.
    指定者:
    
    append 在接口中 Appendable
    
    参数:
    
    csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.
    
    返回:
    
    This writer
    
    抛出:
    
    IOException - If an I/O error occurs
    
    从以下版本开始:
    
    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()) 
```
    指定者:
    
    append 在接口中 Appendable
    
    参数:
    
    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
    
    返回:
    
    This writer
    
    抛出:
    
    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
    
    从以下版本开始:
    
    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) 
```
    指定者:
    
    append 在接口中 Appendable
    
    参数:
    
    c - The 16-bit character to append
    
    返回:
    
    This writer
    
    抛出:
    
    IOException - If an I/O error occurs
    
    从以下版本开始:
    
    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.
    
    指定者:
    
    flush 在接口中 Flushable
    
    抛出:
    
    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.
    
    指定者:
    
    close 在接口中 AutoCloseable
    
    指定者:
    
    close 在接口中 Closeable
    
    抛出:
    
    IOException - If an I/O error occurs

类 Writer

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

lock

构造器详细资料

Writer

Writer

方法详细资料

write

write

write

write

write

append

append

append

flush

close