# Class CharChunk

java.lang.Object
org.apache.tomcat.util.buf.AbstractChunk
org.apache.tomcat.util.buf.CharChunk

All Implemented Interfaces:
  `Serializable, CharSequence, Cloneable`

public final class CharChunk extends AbstractChunk implements CharSequence
Utilities to manipulate char chunks. While String is the easiest way to manipulate chars ( search, substrings, etc), it is known to not be the most efficient solution - Strings are designed as immutable and secure objects.

See Also:
  - Serialized Form

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static interface`
  `CharChunk.CharInputChannel`
  Input interface, used when the buffer is empty.
  `static interface`
  `CharChunk.CharOutputChannel`
  When we need more space we'll either grow the buffer ( up to the limit ) or send it to a channel.

- ## Field Summary

  ### Fields inherited from class AbstractChunk

  `ARRAY_MAX_SIZE, end, hasHashCode, isSet, sm, start`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `CharChunk()`
  Creates a new, uninitialized CharChunk object.
  `CharChunk(int initial)`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `allocate(int initial, int limit)`
  `void`
  `append(char c)`
  `void`
  `append(char[] src, int off, int len)`
  Add data to the buffer.
  `void`
  `append(String s)`
  Append a string to the buffer.
  `void`
  `append(String s, int off, int len)`
  Append a string to the buffer.
  `void`
  `append(CharChunk src)`
  `char`
  `charAt(int index)`
  `Object`
  `clone()`
  `boolean`
  `endsWith(String s)`
  `boolean`
  `equals(char[] b2, int off2, int len2)`
  `boolean`
  `equals(Object obj)`
  `boolean`
  `equals(String s)`
  Compares the message bytes to the specified String object.
  `boolean`
  `equals(CharChunk cc)`
  `boolean`
  `equalsIgnoreCase(String s)`
  Compares the message bytes to the specified String object.
  `void`
  `flushBuffer()`
  Send the buffer to the sink.
  `char[]`
  `getBuffer()`
  `protected int`
  `getBufferElement(int index)`
  `char[]`
  `getChars()`
  `int`
  `indexOf(char c)`
  `static int`
  `indexOf(char[] chars, int start, int end, char s)`
  Returns the first instance of the given character in the given char array between the specified start and end.
  `int`
  `indexOf(char c, int starting)`
  Returns the first instance of the given character in this CharChunk starting at the specified char.
  `int`
  `length()`
  `void`
  `makeSpace(int count)`
  Make space for len chars.
  `void`
  `setCharInputChannel(CharChunk.CharInputChannel in)`
  When the buffer is empty, read the data from the input channel.
  `void`
  `setCharOutputChannel(CharChunk.CharOutputChannel out)`
  When the buffer is full, write the data to the output channel.
  `void`
  `setChars(char[] c, int off, int len)`
  Sets the buffer to the specified sub array of characters.
  `void`
  `setOptimizedWrite(boolean optimizedWrite)`
  Deprecated.
  Unused code.
  `boolean`
  `startsWith(String s)`
  `boolean`
  `startsWithIgnoreCase(String s, int pos)`
  Returns true if the buffer starts with the specified string.
  `CharSequence`
  `subSequence(int start, int end)`
  `int`
  `substract()`
  Deprecated.
  `int`
  `substract(char[] dest, int off, int len)`
  Deprecated.
  `int`
  `subtract()`
  `int`
  `subtract(char[] dest, int off, int len)`
  `String`
  `toString()`
  `String`
  `toStringInternal()`

  ### Methods inherited from class AbstractChunk

  `getEnd, getLength, getLimit, getLimitInternal, getOffset, getStart, hash, hashCode, indexOf, isNull, recycle, setEnd, setLimit, setOffset, setStart`

  ### Methods inherited from class Object

  `finalize, getClass, notify, notifyAll, wait, wait, wait`

  ### Methods inherited from interface CharSequence

  `chars, codePoints, getChars, isEmpty`

- ## Constructor Details

  - ### CharChunk

    public CharChunk()
    Creates a new, uninitialized CharChunk object.

  - ### CharChunk

    public CharChunk(int initial)

- ## Method Details

  - ### clone

    public Object clone() throws CloneNotSupportedException
    Overrides:
      `clone` in class `Object`
    Throws:
      `CloneNotSupportedException`

  - ### allocate

    public void allocate(int initial, int limit)

  - ### setChars

    public void setChars(char[] c, int off, int len)
    Sets the buffer to the specified sub array of characters.
    Parameters:
      `c` - the characters
      `off` - the start offset of the characters
      `len` - the length of the characters

  - ### getChars

    public char[] getChars()
    Returns:
      the buffer.

  - ### getBuffer

    public char[] getBuffer()
    Returns:
      the buffer.

  - ### setCharInputChannel

    public void setCharInputChannel(CharChunk.CharInputChannel in)
    When the buffer is empty, read the data from the input channel.
    Parameters:
      `in` - The input channel

  - ### setCharOutputChannel

    public void setCharOutputChannel(CharChunk.CharOutputChannel out)
    When the buffer is full, write the data to the output channel. Also used when large amount of data is appended. If not set, the buffer will grow to the limit.
    Parameters:
      `out` - The output channel

  - ### append

    public void append(char c) throws IOException
    Throws:
      `IOException`

  - ### append

    public void append(CharChunk src) throws IOException
    Throws:
      `IOException`

  - ### append

    public void append(char[] src, int off, int len) throws IOException
    Add data to the buffer.
    Parameters:
      `src` - Char array
      `off` - Offset
      `len` - Length
    Throws:
      `IOException` - Writing overflow data to the output channel failed

  - ### append

    public void append(String s) throws IOException
    Append a string to the buffer.
    Parameters:
      `s` - The string
    Throws:
      `IOException` - Writing overflow data to the output channel failed

  - ### append

    public void append(String s, int off, int len) throws IOException
    Append a string to the buffer.
    Parameters:
      `s` - The string
      `off` - Offset
      `len` - Length
    Throws:
      `IOException` - Writing overflow data to the output channel failed

  - ### substract

    @Deprecated public int substract() throws IOException
    Deprecated.
    Throws:
      `IOException`

  - ### subtract

    public int subtract() throws IOException
    Throws:
      `IOException`

  - ### substract

    @Deprecated public int substract(char[] dest, int off, int len) throws IOException
    Deprecated.
    Throws:
      `IOException`

  - ### subtract

    public int subtract(char[] dest, int off, int len) throws IOException
    Throws:
      `IOException`

  - ### flushBuffer

    public void flushBuffer() throws IOException
    Send the buffer to the sink. Called by append() when the limit is reached. You can also call it explicitly to force the data to be written.
    Throws:
      `IOException` - Writing overflow data to the output channel failed

  - ### makeSpace

    public void makeSpace(int count)
    Make space for len chars. If len is small, allocate a reserve space too. Never grow bigger than the limit or `AbstractChunk.ARRAY_MAX_SIZE`.
    Parameters:
      `count` - The size

  - ### toString

    public String toString()
    Specified by:
      `toString` in interface `CharSequence`
    Overrides:
      `toString` in class `Object`

  - ### toStringInternal

    public String toStringInternal()

  - ### equals

    public boolean equals(Object obj)
    Overrides:
      `equals` in class `Object`

  - ### equals

    public boolean equals(String s)
    Compares the message bytes to the specified String object.
    Parameters:
      `s` - the String to compare
    Returns:
      `true` if the comparison succeeded, `false` otherwise

  - ### equalsIgnoreCase

    public boolean equalsIgnoreCase(String s)
    Compares the message bytes to the specified String object.
    Parameters:
      `s` - the String to compare
    Returns:
      `true` if the comparison succeeded, `false` otherwise

  - ### equals

    public boolean equals(CharChunk cc)

  - ### equals

    public boolean equals(char[] b2, int off2, int len2)

  - ### startsWith

    public boolean startsWith(String s)
    Parameters:
      `s` - The string
    Returns:
      `true` if the message bytes starts with the specified string.

  - ### startsWithIgnoreCase

    public boolean startsWithIgnoreCase(String s, int pos)
    Returns true if the buffer starts with the specified string.
    Parameters:
      `s` - the string
      `pos` - The position
    Returns:
      `true` if the start matches

  - ### endsWith

    public boolean endsWith(String s)
    Parameters:
      `s` - The string
    Returns:
      `true` if the message bytes end with the specified string.

  - ### getBufferElement

    protected int getBufferElement(int index)
    Specified by:
      `getBufferElement` in class `AbstractChunk`
    Parameters:
      `index` - the element location in the buffer
    Returns:
      the element

  - ### indexOf

    public int indexOf(char c)

  - ### indexOf

    public int indexOf(char c, int starting)
    Returns the first instance of the given character in this CharChunk starting at the specified char. If the character is not found, -1 is returned.
    Parameters:
      `c` - The character
      `starting` - The start position
    Returns:
      The position of the first instance of the character or -1 if the character is not found.

  - ### indexOf

    public static int indexOf(char[] chars, int start, int end, char s)
    Returns the first instance of the given character in the given char array between the specified start and end.
    Parameters:
      `chars` - The array to search
      `start` - The point to start searching from in the array
      `end` - The point to stop searching in the array
      `s` - The character to search for
    Returns:
      The position of the first instance of the character or -1 if the character is not found.

  - ### charAt

    public char charAt(int index)
    Specified by:
      `charAt` in interface `CharSequence`

  - ### subSequence

    public CharSequence subSequence(int start, int end)
    Specified by:
      `subSequence` in interface `CharSequence`

  - ### length

    public int length()
    Specified by:
      `length` in interface `CharSequence`

  - ### setOptimizedWrite

    @Deprecated public void setOptimizedWrite(boolean optimizedWrite)
    Deprecated.
    Unused code. This is now a NO-OP and will be removed without replacement in Tomcat 10.
    NO-OP.
    Parameters:
      `optimizedWrite` - Ignored