Classe astratta per scrivere flussi di caratteri filtrati. La stessa classe astratta FilterWriter fornisce metodi predefiniti che passano tutte le richieste al flusso contenuto. Le sottoclassi di FilterWriter dovrebbero sovrascrivere alcuni di questi metodi e potrebbero anche fornire metodi e campi aggiuntivi. Costruttore:
protetto FilterWriter(Scrittore in uscita):
Crea un nuovo scrittore filtrato. Metodi:
vuoto vicino() :
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 void close() throws IOException Throws: IOException
svuotamento vuoto() :
Flushes the stream.
Syntax : public void flush() throws IOException Throws: IOException
void write(char[] cbuf int off int len) :
Writes a portion of an array of characters.
Syntax : public void write(char[] cbuf int off int len) throws IOException Parameters: cbuf - Buffer of characters to be written off - Offset from which to start reading characters len - Number of characters to be written Throws: IOException
void write(int c):
Writes a single character.
Syntax : public void write(int c) throws IOException Parameters: c - int specifying a character 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 - String to be written off - Offset from which to start reading characters len - Number of characters to be written Throws: IOException
Programma: Java
//Java program demonstrating FilterWriter methodsimportjava.io.FilterWriter;importjava.io.StringWriter;importjava.io.Writer;classFilterWriterDemo{publicstaticvoidmain(String[]args)throwsException{FilterWriterfr=null;Writerwr=null;wr=newStringWriter();fr=newFilterWriter(wr){};Stringstr='Geeksfor';charc[]={'G''e''e''k'};//illustrating write(String strint offint len)fr.write(str);//illustrating flush()fr.flush();//illustrating write(char[] cffint offint len)fr.write(c);//illustrating write(int c)fr.write('s');System.out.print(wr.toString());//close the streamfr.close();}}