Enum HtmlEscapeLevel

java.lang.Object
java.lang.Enum<HtmlEscapeLevel>
org.unbescape.html.HtmlEscapeLevel
All Implemented Interfaces:
Serializable, Comparable<HtmlEscapeLevel>, java.lang.constant.Constable

public enum HtmlEscapeLevel extends Enum<HtmlEscapeLevel>

Levels defined for HTML escape/unescape operations:

  • Level 0: Escape only markup-significant characters, excluding the apostrophe. Therefore <, >, & and " will be escaped. This level can be used for escaping texts and also tag attributes that are always surrounded by double quotes, whenever the apostrophe (') is considered a safe character and the user prefers it not to be escaped for legibility reasons (e.g. might denote literals in expression languages like OGNL). Note the result of a level-0 escape operation might still contain non-ASCII characters if they existed in input, and therefore you will still need to correctly manage your input/output character encoding settings.
  • Level 1: Escape only markup-significant characters (including the apostrophe). Therefore <, >, &, " and ' will be escaped. This level is sometimes called XML escape or XML-style escape, though it is not exactly equivalent to XML due to some HTML specificities. It is equivalent to the JSP escape configured by the escapeXml attribute in JSTL's <c:out ... /> tags, and safe for use in texts and also tag attributes that are always quoted —be it with single (apostrophe) or double quotes. Note the result of a level-1 escape operation might still contain non-ASCII characters if they existed in input, and therefore you will still need to correctly manage your input/output character encoding settings.
  • Level 2: Escape all markup-significant characters (as defined in level 1), plus all non-ASCII characters. The result of a level-2 escape operation is therefore always ASCII-only text, and safer to use in complex scenarios with mixed input/output character encodings. This level can be used for escaping texts and also tag attributes that are always quoted —be it with single (apostrophe) or double quotes.
  • Level 3: Escape all non-alphanumeric characters, this is, all but those in the A-Z, a-z and 0-9 ranges. This level can be safely used for escaping texts and also tag attributes, even when these tag attributes are unquoted.
  • Level 4: Escape all characters, even alphanumeric ones.

For further information, see the Glossary and the References sections at the documentation for the HtmlEscape class.

Since:
1.0.0
  • Enum Constant Details

    • LEVEL_0_ONLY_MARKUP_SIGNIFICANT_EXCEPT_APOS

      public static final HtmlEscapeLevel LEVEL_0_ONLY_MARKUP_SIGNIFICANT_EXCEPT_APOS
      Level 0 escape: escape only markup-significant characters, excluding the apostrophe: <, >, & and "
    • LEVEL_1_ONLY_MARKUP_SIGNIFICANT

      public static final HtmlEscapeLevel LEVEL_1_ONLY_MARKUP_SIGNIFICANT
      Level 1 escape (XML-style): escape only markup-significant characters (including the apostrophe): <, >, &, " and '
    • LEVEL_2_ALL_NON_ASCII_PLUS_MARKUP_SIGNIFICANT

      public static final HtmlEscapeLevel LEVEL_2_ALL_NON_ASCII_PLUS_MARKUP_SIGNIFICANT
      Level 2 escape: escape markup-significant characters plus all non-ASCII characters (result will always be ASCII).
    • LEVEL_3_ALL_NON_ALPHANUMERIC

      public static final HtmlEscapeLevel LEVEL_3_ALL_NON_ALPHANUMERIC
      Level 3 escape: escape all non-alphanumeric characteres (escape all but those in the A-Z, a-z and 0-9 ranges).
    • LEVEL_4_ALL_CHARACTERS

      public static final HtmlEscapeLevel LEVEL_4_ALL_CHARACTERS
      Level 4 escape: escape all characters, including alphanumeric.
  • Field Details

    • escapeLevel

      private final int escapeLevel
  • Constructor Details

    • HtmlEscapeLevel

      private HtmlEscapeLevel(int escapeLevel)
  • Method Details

    • values

      public static HtmlEscapeLevel[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared
    • valueOf

      public static HtmlEscapeLevel valueOf(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null
    • forLevel

      public static HtmlEscapeLevel forLevel(int level)

      Utility method for obtaining an enum value from its corresponding int level value.

      Parameters:
      level - the level
      Returns:
      the escape level enum constant, or IllegalArgumentException if level does not exist.
    • getEscapeLevel

      public int getEscapeLevel()
      Return the int escape level.
      Returns:
      the escape level.