java.io

Class CharArrayWriter

  • All Implemented Interfaces:
    Closeable, Flushable, Appendable, AutoCloseable 

    public class CharArrayWriter
extends Writer
    This class implements a character buffer that can be used as an Writer. The buffer automatically grows when data is written to the stream. The data can be retrieved using toCharArray() and toString().

    Note: Invoking close() on this class has no effect, and methods of this class can be called after the stream has closed without generating an IOException.

    Since:
    JDK1.1

    • Field Summary

      Fields

      Modifier and Type Field and Description
      protected char[] buf
      The buffer where data is stored.
      protected int count
      The number of chars in the buffer.

    • Constructor Summary

      Constructors

      Constructor and Description
      CharArrayWriter()
      Creates a new CharArrayWriter.
      CharArrayWriter(int initialSize)
      Creates a new CharArrayWriter with the specified initial size.

    • Method Summary

      Modifier and Type Method and Description
      CharArrayWriter append(char c)
      Appends the specified character to this writer.
      CharArrayWriter append(CharSequence csq)
      Appends the specified character sequence to this writer.
      CharArrayWriter append(CharSequence csq, int start, int end)
      Appends a subsequence of the specified character sequence to this writer.
      void close()
      Close the stream.
      void flush()
      Flush the stream.
      void reset()
      Resets the buffer so that you can use it again without throwing away the already allocated buffer.
      int size()
      Returns the current size of the buffer.
      char[] toCharArray()
      Returns a copy of the input data.
      String toString()
      Converts input data to a string.
      void write(char[] c, int off, int len)
      Writes characters to the buffer.
      void write(int c)
      Writes a character to the buffer.
      void write(String str, int off, int len)
      Write a portion of a string to the buffer.
      void writeTo(Writer out)
      Writes the contents of the buffer to another character stream.

    • Field Detail

      • buf

        protected char[] buf
        The buffer where data is stored.

      • count

        protected int count
        The number of chars in the buffer.

    • Constructor Detail

      • CharArrayWriter

        public CharArrayWriter()
        Creates a new CharArrayWriter.

      • CharArrayWriter

        public CharArrayWriter(int initialSize)
        Creates a new CharArrayWriter with the specified initial size.
        Parameters:
        initialSize - an int specifying the initial buffer size.
        Throws:
        IllegalArgumentException - if initialSize is negative

    • Method Detail

      • write

        public void write(int c)
        Writes a character to the buffer.
        Overrides:
        write in class  Writer
        Parameters:
        c - int specifying a character to be written

      • write

        public void write(char[] c,
                  int off,
                  int len)
        Writes characters to the buffer.
        Specified by:
        write in class  Writer
        Parameters:
        c - the data to be written
        off - the start offset in the data
        len - the number of chars that are written

      • write

        public void write(String str,
                  int off,
                  int len)
        Write a portion of a string to the buffer.
        Overrides:
        write in class  Writer
        Parameters:
        str - String to be written from
        off - Offset from which to start reading characters
        len - Number of characters to be written

      • writeTo

        public void writeTo(Writer out)
             throws IOException
        Writes the contents of the buffer to another character stream.
        Parameters:
        out - the output stream to write to
        Throws:
        IOException - If an I/O error occurs.

      • append

        public CharArrayWriter 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.

        Specified by:
        append in interface  Appendable
        Overrides:
        append in class  Writer
        Parameters:
        csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.
        Returns:
        This writer
        Since:
        1.5

      • append

        public CharArrayWriter append(CharSequence csq,
                              int start,
                              int end)
        Appends a subsequence of the specified character sequence to this writer.

        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
        Overrides:
        append in class  Writer
        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()
        Since:
        1.5

      • append

        public CharArrayWriter append(char 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)
        Specified by:
        append in interface  Appendable
        Overrides:
        append in class  Writer
        Parameters:
        c - The 16-bit character to append
        Returns:
        This writer
        Since:
        1.5

      • reset

        public void reset()
        Resets the buffer so that you can use it again without throwing away the already allocated buffer.

      • toCharArray

        public char[] toCharArray()
        Returns a copy of the input data.
        Returns:
        an array of chars copied from the input data.

      • size

        public int size()
        Returns the current size of the buffer.
        Returns:
        an int representing the current size of the buffer.

      • toString

        public String toString()
        Converts input data to a string.
        Overrides:
        toString in class  Object
        Returns:
        the string.

      • flush

        public void flush()
        Flush the stream.

      • close

        public void close()
        Close the stream. This method does not release the buffer, since its contents might still be required. Note: Invoking this method in this class will have no effect.