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Classe Java.io.Writer en Java

Aquesta classe abstracta per escriure en fluxos de caràcters. Els únics mètodes que ha d'implementar una subclasse són write(char[] int int) flush() i close(). Tanmateix, la majoria de les subclasses anul·laran alguns dels mètodes definits aquí per tal de proporcionar una funcionalitat addicional més eficient o ambdues. Constructor
    protegit Writer():Crea un escriptor nou de flux de personatges les seccions crítiques del qual es sincronitzaran amb el propi escriptor. Escriptor protegit (bloqueig d'objectes):Crea un escriptor nou de flux de personatges les seccions crítiques del qual es sincronitzaran amb l'objecte donat.
Mètodes:
    Writer append (car c): 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)
      Syntax :  public Writer append(char c) throws IOException   Parameters:   c - The 16-bit character to append   Returns:   This writer   Throws:   IOException
    Writer append (CharSequence csq): 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.
      Syntax :  public Writer append(CharSequence csq) throws IOException   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
    Writer append(CharSequence csq int start int end): Appends a subsequence of the specified character sequence to this writer.Appends a subsequence of the specified character sequence to this writer
      Syntax :  public Writer append(CharSequence csq int start int end) throws IOException   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 IOException
    abstract void close(): 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.
      Syntax :  public abstract void close() throws IOException   Throws:   IOException 
    abstract void flush(): 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.
      Syntax :  public abstract void flush() throws IOException   Throws:   IOException
    void write(char[] cbuf): Writes an array of characters.
      Syntax :  public void write(char[] cbuf) throws IOException   Parameters:   cbuf - Array of characters to be written   Throws:   IOException - If an I/O error occurs
    abstract void write(char[] cbuf int off int len): Writes a portion of an array of characters.
      Syntax :  public abstract void write(char[] cbuf int off int len) throws IOException   Parameters:   cbuf - Array of characters off - Offset from which to start writing characters len - Number of characters to write   Throws:   IOException
    void write(int c): 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.
      Syntax :  public void write(int c) throws IOException   Parameters:   c - int specifying a character to be written   Throws:   IOException
    void write(String str): Writes a string.
      Syntax :  public void write(String str) throws IOException   Parameters:   str - String to be written   Throws:   IOException
    void write(String str int off int len): Writes a portion of a string.
      Syntax :  public void write(String str int off int len) throws IOException   Parameters:   str - A String off - Offset from which to start writing characters len - Number of characters to write   Throws:   IndexOutOfBoundsException 
Programa: Java
//Java program demonstrating Writer methods import java.io.IOException; import java.io.PrintWriter; import java.io.Writer; class WriterDemo {  public static void main(String[] args) throws IOException  {  Writer wr=new PrintWriter(System.out);  char c[] = {'B''C''D''E''F'};  CharSequence cs = 'JKL';  String str = 'GHI';  //illustrating write(int c)  wr.write(65);    //flushing the stream  wr.flush();    //illustrating write(char[] cint offint len)  wr.write(c);  wr.flush();    //illustrating write(String strint offint len)  wr.write(str);  wr.flush();    //illustrating append(Charsequence csint startint end)  wr.append(cs);  wr.flush();    //illustrating append(int ch)  wr.append('M');  wr.flush();  //closing the stream  wr.close();  } } 
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