Package java.io

Class CharArrayWriter

java.lang.Object
java.io.Writer
java.io.CharArrayWriter
All Implemented Interfaces:
Closeable, Flushable, Appendable, AutoCloseable
public class CharArrayWriter
extends Writer
A specialized Writer for class for writing content to an (internal) char array. As bytes are written to this writer, the char array may be expanded to hold more characters. When the writing is considered to be finished, a copy of the char array can be requested from the class.
See Also:
CharArrayReader

  • Field Summary

    Fields
    Modifier and Type Field Description
    protected char[] buf
    The buffer for characters.
    protected int count
    The ending index of the buffer.

    Fields inherited from class java.io.Writer

    lock

  • Constructor Summary

    Constructors
    Constructor Description
    CharArrayWriter()
    Constructs a new CharArrayWriter which has a buffer allocated with the default size of 32 characters.
    CharArrayWriter​(int initialSize)
    Constructs a new CharArrayWriter which has a buffer allocated with the size of initialSize characters.

  • Method Summary

    Modifier and Type Method Description
    CharArrayWriter append​(char c)
    Appends a char c to the CharArrayWriter.
    CharArrayWriter append​(CharSequence csq)
    Appends a CharSequence to the CharArrayWriter.
    CharArrayWriter append​(CharSequence csq, int start, int end)
    Append a subsequence of a CharSequence to the CharArrayWriter.
    void close()
    Closes this writer.
    void flush()
    Flushes this writer.
    void reset()
    Resets this writer.
    int size()
    Returns the size of this writer, that is the number of characters it stores.
    char[] toCharArray()
    Returns the contents of the receiver as a char array.
    String toString()
    Returns the contents of this CharArrayWriter as a string.
    void write​(char[] buffer, int offset, int len)
    Writes count characters starting at offset in c to this writer.
    void write​(int oneChar)
    Writes the specified character oneChar to this writer.
    void write​(String str, int offset, int count)
    Writes count characters starting at offset from the string str to this CharArrayWriter.
    void writeTo​(Writer out)
    Writes the contents of this CharArrayWriter to another Writer.

    Methods inherited from class java.io.Writer

    write, write

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • buf

      protected char[] buf
      The buffer for characters.

    • count

      protected int count
      The ending index of the buffer.

  • Constructor Details

    • CharArrayWriter

      public CharArrayWriter()
      Constructs a new CharArrayWriter which has a buffer allocated with the default size of 32 characters. This buffer is also used as the lock to synchronize access to this writer.

    • CharArrayWriter

      public CharArrayWriter​(int initialSize)
      Constructs a new CharArrayWriter which has a buffer allocated with the size of initialSize characters. The buffer is also used as the lock to synchronize access to this writer.
      Parameters:
      initialSize - the initial size of this CharArrayWriters buffer.
      Throws:
      IllegalArgumentException - if initialSize < 0.

  • Method Details

    • close

      public void close()
      Closes this writer. The implementation in CharArrayWriter does nothing.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in class Writer

    • flush

      public void flush()
      Flushes this writer. The implementation in CharArrayWriter does nothing.
      Specified by:
      flush in interface Flushable
      Specified by:
      flush in class Writer

    • reset

      public void reset()
      Resets this writer. The current write position is reset to the beginning of the buffer. All written characters are lost and the size of this writer is set to 0.

    • size

      public int size()
      Returns the size of this writer, that is the number of characters it stores. This number changes if this writer is reset or when more characters are written to it.
      Returns:
      this CharArrayWriter's current size in characters.

    • toCharArray

      public char[] toCharArray()
      Returns the contents of the receiver as a char array. The array returned is a copy and any modifications made to this writer after calling this method are not reflected in the result.
      Returns:
      this CharArrayWriter's contents as a new char array.

    • toString

      public String toString()
      Returns the contents of this CharArrayWriter as a string. The string returned is a copy and any modifications made to this writer after calling this method are not reflected in the result.
      Overrides:
      toString in class Object
      Returns:
      this CharArrayWriters contents as a new string.

    • write

      public void write​(char[] buffer, int offset, int len)
      Writes count characters starting at offset in c to this writer.
      Specified by:
      write in class Writer
      Parameters:
      buffer - the non-null array containing characters to write.
      offset - the index of the first character in buf to write.
      len - maximum number of characters to write.
      Throws:
      IndexOutOfBoundsException - if offset < 0 or len < 0, or if offset + len is bigger than the size of c.

    • write

      public void write​(int oneChar)
      Writes the specified character oneChar to this writer. This implementation writes the two low order bytes of the integer oneChar to the buffer.
      Overrides:
      write in class Writer
      Parameters:
      oneChar - the character to write.

    • write

      public void write​(String str, int offset, int count)
      Writes count characters starting at offset from the string str to this CharArrayWriter.
      Overrides:
      write in class Writer
      Parameters:
      str - the non-null string containing the characters to write.
      offset - the index of the first character in str to write.
      count - the number of characters from str to write.
      Throws:
      NullPointerException - if str is null.
      StringIndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is bigger than the length of str.

    • writeTo

      public void writeTo​(Writer out) throws IOException
      Writes the contents of this CharArrayWriter to another Writer. The output is all the characters that have been written to the receiver since the last reset or since it was created.
      Parameters:
      out - the non-null Writer on which to write the contents.
      Throws:
      NullPointerException - if out is null.
      IOException - if an error occurs attempting to write out the contents.

    • append

      public CharArrayWriter append​(char c)
      Appends a char c to the CharArrayWriter. The method works the same way as write(c).
      Specified by:
      append in interface Appendable
      Overrides:
      append in class Writer
      Parameters:
      c - the character appended to the CharArrayWriter.
      Returns:
      this CharArrayWriter.

    • append

      public CharArrayWriter append​(CharSequence csq)
      Appends a CharSequence to the CharArrayWriter. The method works the same way as write(csq.toString()). If csq is null, then it will be substituted with the string "null".
      Specified by:
      append in interface Appendable
      Overrides:
      append in class Writer
      Parameters:
      csq - the CharSequence appended to the CharArrayWriter, may be null.
      Returns:
      this CharArrayWriter.

    • append

      public CharArrayWriter append​(CharSequence csq, int start, int end)
      Append a subsequence of a CharSequence to the CharArrayWriter. The first and last characters of the subsequence are specified by the parameters start and end. A call to CharArrayWriter.append(csq) works the same way as CharArrayWriter.write(csq.subSequence(start, end).toString). If csq is null, then it will be substituted with the string "null".
      Specified by:
      append in interface Appendable
      Overrides:
      append in class Writer
      Parameters:
      csq - the CharSequence appended to the CharArrayWriter, may be null.
      start - the index of the first character in the CharSequence appended to the CharArrayWriter.
      end - the index of the character after the last one in the CharSequence appended to the CharArrayWriter.
      Returns:
      this CharArrayWriter.
      Throws:
      IndexOutOfBoundsException - if start < 0, end < 0, start > end, or if end is greater than the length of csq.