org.apache.xerces.util

## Class XMLChar

- java.lang.Object
- - org.apache.xerces.util.XMLChar

-     public class XMLChar
      extends java.lang.Object

  This class defines the basic XML character properties. The data in this class can be used to verify that a character is a valid XML character or if the character is a space, name start, or name character.

  A series of convenience methods are supplied to ease the burden of the developer. Because inlining the checks can improve per character performance, the tables of character properties are public. Using the character as an index into the `CHARS` array and applying the appropriate mask flag (e.g. `MASK_VALID`), yields the same results as calling the convenience methods. There is one exception: check the comments for the `isValid` method for details.

  Version:
    $Id: XMLChar.java 674379 2008-07-07 00:53:05Z mrglavas $
  Author:
    Glenn Marcy, IBM, Andy Clark, IBM, Eric Ye, IBM, Arnaud Le Hors, IBM, Michael Glavassevich, IBM, Rahul Srivastava, Sun Microsystems Inc.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `MASK_CONTENT` Content character mask.
    `static int` | `MASK_NAME` Name character mask.
    `static int` | `MASK_NAME_START` Name start character mask.
    `static int` | `MASK_NCNAME` NCName character mask.
    `static int` | `MASK_NCNAME_START` NCName start character mask.
    `static int` | `MASK_PUBID` Pubid character mask.
    `static int` | `MASK_SPACE` Space character mask.
    `static int` | `MASK_VALID` Valid character mask.

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `XMLChar()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static char` | `highSurrogate(int c)` Returns the high surrogate of a supplemental character
    `static boolean` | `isContent(int c)` Returns true if the specified character can be considered content.
    `static boolean` | `isHighSurrogate(int c)` Returns whether the given character is a high surrogate
    `static boolean` | `isInvalid(int c)` Returns true if the specified character is invalid.
    `static boolean` | `isLowSurrogate(int c)` Returns whether the given character is a low surrogate
    `static boolean` | `isMarkup(int c)` Returns true if the specified character can be considered markup.
    `static boolean` | `isName(int c)` Returns true if the specified character is a valid name character as defined by production [4] in the XML 1.0 specification.
    `static boolean` | `isNameStart(int c)` Returns true if the specified character is a valid name start character as defined by production [5] in the XML 1.0 specification.
    `static boolean` | `isNCName(int c)` Returns true if the specified character is a valid NCName character as defined by production [5] in Namespaces in XML recommendation.
    `static boolean` | `isNCNameStart(int c)` Returns true if the specified character is a valid NCName start character as defined by production [4] in Namespaces in XML recommendation.
    `static boolean` | `isPubid(int c)` Returns true if the specified character is a valid Pubid character as defined by production [13] in the XML 1.0 specification.
    `static boolean` | `isSpace(int c)` Returns true if the specified character is a space character as defined by production [3] in the XML 1.0 specification.
    `static boolean` | `isSupplemental(int c)` Returns true if the specified character is a supplemental character.
    `static boolean` | `isValid(int c)` Returns true if the specified character is valid.
    `static boolean` | `isValidIANAEncoding(java.lang.String ianaEncoding)` Returns true if the encoding name is a valid IANA encoding.
    `static boolean` | `isValidJavaEncoding(java.lang.String javaEncoding)` Returns true if the encoding name is a valid Java encoding.
    `static boolean` | `isValidName(java.lang.String name)` Check to see if a string is a valid Name according to [5] in the XML 1.0 Recommendation
    `static boolean` | `isValidNCName(java.lang.String ncName)` Check to see if a string is a valid NCName according to [4] from the XML Namespaces 1.0 Recommendation
    `static boolean` | `isValidNmtoken(java.lang.String nmtoken)` Check to see if a string is a valid Nmtoken according to [7] in the XML 1.0 Recommendation
    `static char` | `lowSurrogate(int c)` Returns the low surrogate of a supplemental character
    `static int` | `supplemental(char h, char l)` Returns true the supplemental character corresponding to the given surrogates.
    `static java.lang.String` | `trim(java.lang.String value)` Trims space characters as defined by production [3] in the XML 1.0 specification from both ends of the given string.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### MASK_VALID

          public static final int MASK_VALID

      Valid character mask.
      See Also:
        Constant Field Values

    - #### MASK_SPACE

          public static final int MASK_SPACE

      Space character mask.
      See Also:
        Constant Field Values

    - #### MASK_NAME_START

          public static final int MASK_NAME_START

      Name start character mask.
      See Also:
        Constant Field Values

    - #### MASK_NAME

          public static final int MASK_NAME

      Name character mask.
      See Also:
        Constant Field Values

    - #### MASK_PUBID

          public static final int MASK_PUBID

      Pubid character mask.
      See Also:
        Constant Field Values

    - #### MASK_CONTENT

          public static final int MASK_CONTENT

      Content character mask. Special characters are those that can be considered the start of markup, such as '<' and '&'. The various newline characters are considered special as well. All other valid XML characters can be considered content.

      This is an optimization for the inner loop of character scanning.

      See Also:
        Constant Field Values

    - #### MASK_NCNAME_START

          public static final int MASK_NCNAME_START

      NCName start character mask.
      See Also:
        Constant Field Values

    - #### MASK_NCNAME

          public static final int MASK_NCNAME

      NCName character mask.
      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### XMLChar

          public XMLChar()

  - ### Method Detail

    - #### isSupplemental

          public static boolean isSupplemental(int c)

      Returns true if the specified character is a supplemental character.
      Parameters:
        `c` - The character to check.

    - #### supplemental

          public static int supplemental(char h,
                         char l)

      Returns true the supplemental character corresponding to the given surrogates.
      Parameters:
        `h` - The high surrogate.
        `l` - The low surrogate.

    - #### highSurrogate

          public static char highSurrogate(int c)

      Returns the high surrogate of a supplemental character
      Parameters:
        `c` - The supplemental character to "split".

    - #### lowSurrogate

          public static char lowSurrogate(int c)

      Returns the low surrogate of a supplemental character
      Parameters:
        `c` - The supplemental character to "split".

    - #### isHighSurrogate

          public static boolean isHighSurrogate(int c)

      Returns whether the given character is a high surrogate
      Parameters:
        `c` - The character to check.

    - #### isLowSurrogate

          public static boolean isLowSurrogate(int c)

      Returns whether the given character is a low surrogate
      Parameters:
        `c` - The character to check.

    - #### isValid

          public static boolean isValid(int c)

      Returns true if the specified character is valid. This method also checks the surrogate character range from 0x10000 to 0x10FFFF.

      If the program chooses to apply the mask directly to the `CHARS` array, then they are responsible for checking the surrogate character range.

      Parameters:
        `c` - The character to check.

    - #### isInvalid

          public static boolean isInvalid(int c)

      Returns true if the specified character is invalid.
      Parameters:
        `c` - The character to check.

    - #### isContent

          public static boolean isContent(int c)

      Returns true if the specified character can be considered content.
      Parameters:
        `c` - The character to check.

    - #### isMarkup

          public static boolean isMarkup(int c)

      Returns true if the specified character can be considered markup. Markup characters include '<', '&', and '%'.
      Parameters:
        `c` - The character to check.

    - #### isSpace

          public static boolean isSpace(int c)

      Returns true if the specified character is a space character as defined by production [3] in the XML 1.0 specification.
      Parameters:
        `c` - The character to check.

    - #### isNameStart

          public static boolean isNameStart(int c)

      Returns true if the specified character is a valid name start character as defined by production [5] in the XML 1.0 specification.
      Parameters:
        `c` - The character to check.

    - #### isName

          public static boolean isName(int c)

      Returns true if the specified character is a valid name character as defined by production [4] in the XML 1.0 specification.
      Parameters:
        `c` - The character to check.

    - #### isNCNameStart

          public static boolean isNCNameStart(int c)

      Returns true if the specified character is a valid NCName start character as defined by production [4] in Namespaces in XML recommendation.
      Parameters:
        `c` - The character to check.

    - #### isNCName

          public static boolean isNCName(int c)

      Returns true if the specified character is a valid NCName character as defined by production [5] in Namespaces in XML recommendation.
      Parameters:
        `c` - The character to check.

    - #### isPubid

          public static boolean isPubid(int c)

      Returns true if the specified character is a valid Pubid character as defined by production [13] in the XML 1.0 specification.
      Parameters:
        `c` - The character to check.

    - #### isValidName

          public static boolean isValidName(java.lang.String name)

      Check to see if a string is a valid Name according to [5] in the XML 1.0 Recommendation
      Parameters:
        `name` - string to check
      Returns:
        true if name is a valid Name

    - #### isValidNCName

          public static boolean isValidNCName(java.lang.String ncName)

      Check to see if a string is a valid NCName according to [4] from the XML Namespaces 1.0 Recommendation
      Parameters:
        `ncName` - string to check
      Returns:
        true if name is a valid NCName

    - #### isValidNmtoken

          public static boolean isValidNmtoken(java.lang.String nmtoken)

      Check to see if a string is a valid Nmtoken according to [7] in the XML 1.0 Recommendation
      Parameters:
        `nmtoken` - string to check
      Returns:
        true if nmtoken is a valid Nmtoken

    - #### isValidIANAEncoding

          public static boolean isValidIANAEncoding(java.lang.String ianaEncoding)

      Returns true if the encoding name is a valid IANA encoding. This method does not verify that there is a decoder available for this encoding, only that the characters are valid for an IANA encoding name.
      Parameters:
        `ianaEncoding` - The IANA encoding name.

    - #### isValidJavaEncoding

          public static boolean isValidJavaEncoding(java.lang.String javaEncoding)

      Returns true if the encoding name is a valid Java encoding. This method does not verify that there is a decoder available for this encoding, only that the characters are valid for an Java encoding name.
      Parameters:
        `javaEncoding` - The Java encoding name.

    - #### trim

          public static java.lang.String trim(java.lang.String value)

      Trims space characters as defined by production [3] in the XML 1.0 specification from both ends of the given string.
      Parameters:
        `value` - the string to be trimmed
      Returns:
        the given string with the space characters trimmed from both ends

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