Class StringEscapeUtils


  • public class StringEscapeUtils
    extends Object

    Escapes and unescapes Strings for Java, Java Script, HTML and XML.

    #ThreadSafe#

    This code has been adapted from Apache Commons Lang 3.5.

    Since:
    1.0
    • Field Detail

      • ESCAPE_JAVA

        public static final CharSequenceTranslator ESCAPE_JAVA
        Translator object for escaping Java. While escapeJava(String) is the expected method of use, this object allows the Java escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_JSON

        public static final CharSequenceTranslator ESCAPE_JSON
        Translator object for escaping Json. While escapeJson(String) is the expected method of use, this object allows the Json escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_XML10

        public static final CharSequenceTranslator ESCAPE_XML10
        Translator object for escaping XML 1.0. While escapeXml10(String) is the expected method of use, this object allows the XML escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_XML11

        public static final CharSequenceTranslator ESCAPE_XML11
        Translator object for escaping XML 1.1. While escapeXml11(String) is the expected method of use, this object allows the XML escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_HTML3

        public static final CharSequenceTranslator ESCAPE_HTML3
        Translator object for escaping HTML version 3.0. While escapeHtml3(String) is the expected method of use, this object allows the HTML escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_HTML4

        public static final CharSequenceTranslator ESCAPE_HTML4
        Translator object for escaping HTML version 4.0. While escapeHtml4(String) is the expected method of use, this object allows the HTML escaping functionality to be used as the foundation for a custom translator.
      • ESCAPE_CSV

        public static final CharSequenceTranslator ESCAPE_CSV
        Translator object for escaping individual Comma Separated Values. While escapeCsv(String) is the expected method of use, this object allows the CSV escaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_JAVA

        public static final CharSequenceTranslator UNESCAPE_JAVA
        Translator object for unescaping escaped Java. While unescapeJava(String) is the expected method of use, this object allows the Java unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_JSON

        public static final CharSequenceTranslator UNESCAPE_JSON
        Translator object for unescaping escaped Json. While unescapeJson(String) is the expected method of use, this object allows the Json unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_HTML3

        public static final CharSequenceTranslator UNESCAPE_HTML3
        Translator object for unescaping escaped HTML 3.0. While unescapeHtml3(String) is the expected method of use, this object allows the HTML unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_HTML4

        public static final CharSequenceTranslator UNESCAPE_HTML4
        Translator object for unescaping escaped HTML 4.0. While unescapeHtml4(String) is the expected method of use, this object allows the HTML unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_XML

        public static final CharSequenceTranslator UNESCAPE_XML
        Translator object for unescaping escaped XML. While unescapeXml(String) is the expected method of use, this object allows the XML unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_CSV

        public static final CharSequenceTranslator UNESCAPE_CSV
        Translator object for unescaping escaped Comma Separated Value entries. While unescapeCsv(String) is the expected method of use, this object allows the CSV unescaping functionality to be used as the foundation for a custom translator.
      • UNESCAPE_XSI

        public static final CharSequenceTranslator UNESCAPE_XSI
        Translator object for unescaping escaped XSI Value entries. While unescapeXSI(String) is the expected method of use, this object allows the XSI unescaping functionality to be used as the foundation for a custom translator.
    • Constructor Detail

      • StringEscapeUtils

        public StringEscapeUtils()

        StringEscapeUtils instances should NOT be constructed in standard programming.

        Instead, the class should be used as:

        StringEscapeUtils.escapeJava("foo");

        This constructor is public to permit tools that require a JavaBean instance to operate.

    • Method Detail

      • escapeJava

        public static final String escapeJava​(String input)

        Escapes the characters in a String using Java String rules.

        Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

        So a tab becomes the characters '\\' and 't'.

        The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote and forward-slash (/) are escaped.

        Example:

         input string: He didn't say, "Stop!"
         output string: He didn't say, \"Stop!\"
         
        Parameters:
        input - String to escape values in, may be null
        Returns:
        String with escaped values, null if null string input
      • escapeEcmaScript

        public static final String escapeEcmaScript​(String input)

        Escapes the characters in a String using EcmaScript String rules.

        Escapes any values it finds into their EcmaScript String form. Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

        So a tab becomes the characters '\\' and 't'.

        The only difference between Java strings and EcmaScript strings is that in EcmaScript, a single quote and forward-slash (/) are escaped.

        Note that EcmaScript is best known by the JavaScript and ActionScript dialects.

        Example:

         input string: He didn't say, "Stop!"
         output string: He didn\'t say, \"Stop!\"
         
        Security Note. We only provide backslash escaping in this method. For example, '\"' has the output '\\\"' which could result in potential issues in the case where the string being escaped is being used in an HTML tag like <select onmouseover="..." />. If you wish to have more rigorous string escaping, you may consider the ESAPI Libraries. Further, you can view the ESAPI GitHub Org.
        Parameters:
        input - String to escape values in, may be null
        Returns:
        String with escaped values, null if null string input
      • escapeJson

        public static final String escapeJson​(String input)

        Escapes the characters in a String using Json String rules.

        Escapes any values it finds into their Json String form. Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

        So a tab becomes the characters '\\' and 't'.

        The only difference between Java strings and Json strings is that in Json, forward-slash (/) is escaped.

        See http://www.ietf.org/rfc/rfc4627.txt for further details.

        Example:

         input string: He didn't say, "Stop!"
         output string: He didn't say, \"Stop!\"
         
        Parameters:
        input - String to escape values in, may be null
        Returns:
        String with escaped values, null if null string input
      • unescapeJava

        public static final String unescapeJava​(String input)

        Unescapes any Java literals found in the String. For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        a new unescaped String, null if null string input
      • unescapeEcmaScript

        public static final String unescapeEcmaScript​(String input)

        Unescapes any EcmaScript literals found in the String.

        For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        A new unescaped String, null if null string input
        See Also:
        unescapeJava(String)
      • unescapeJson

        public static final String unescapeJson​(String input)

        Unescapes any Json literals found in the String.

        For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        A new unescaped String, null if null string input
        See Also:
        unescapeJava(String)
      • escapeHtml3

        public static final String escapeHtml3​(String input)

        Escapes the characters in a String using HTML entities.

        Supports only the HTML 3.0 entities.

        Parameters:
        input - the String to escape, may be null
        Returns:
        a new escaped String, null if null string input
      • unescapeHtml4

        public static final String unescapeHtml4​(String input)

        Unescapes a string containing entity escapes to a string containing the actual Unicode characters corresponding to the escapes. Supports HTML 4.0 entities.

        For example, the string "&lt;Fran&ccedil;ais&gt;" will become "<Fran´┐Żais>"

        If an entity is unrecognized, it is left alone, and inserted verbatim into the result string. e.g. "&gt;&zzzz;x" will become ">&zzzz;x".

        Parameters:
        input - the String to unescape, may be null
        Returns:
        a new unescaped String, null if null string input
      • unescapeHtml3

        public static final String unescapeHtml3​(String input)

        Unescapes a string containing entity escapes to a string containing the actual Unicode characters corresponding to the escapes. Supports only HTML 3.0 entities.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        a new unescaped String, null if null string input
      • escapeXml10

        public static String escapeXml10​(String input)

        Escapes the characters in a String using XML entities.

        For example: "bread" & "butter" => &quot;bread&quot; &amp; &quot;butter&quot;.

        Note that XML 1.0 is a text-only format: it cannot represent control characters or unpaired Unicode surrogate codepoints, even after escaping. escapeXml10 will remove characters that do not fit in the following ranges:

        #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]

        Though not strictly necessary, escapeXml10 will escape characters in the following ranges:

        [#x7F-#x84] | [#x86-#x9F]

        The returned string can be inserted into a valid XML 1.0 or XML 1.1 document. If you want to allow more non-text characters in an XML 1.1 document, use escapeXml11(String).

        Parameters:
        input - the String to escape, may be null
        Returns:
        a new escaped String, null if null string input
        See Also:
        unescapeXml(java.lang.String)
      • escapeXml11

        public static String escapeXml11​(String input)

        Escapes the characters in a String using XML entities.

        For example: "bread" & "butter" => &quot;bread&quot; &amp; &quot;butter&quot;.

        XML 1.1 can represent certain control characters, but it cannot represent the null byte or unpaired Unicode surrogate codepoints, even after escaping. escapeXml11 will remove characters that do not fit in the following ranges:

        [#x1-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]

        escapeXml11 will escape characters in the following ranges:

        [#x1-#x8] | [#xB-#xC] | [#xE-#x1F] | [#x7F-#x84] | [#x86-#x9F]

        The returned string can be inserted into a valid XML 1.1 document. Do not use it for XML 1.0 documents.

        Parameters:
        input - the String to escape, may be null
        Returns:
        a new escaped String, null if null string input
        See Also:
        unescapeXml(java.lang.String)
      • unescapeXml

        public static final String unescapeXml​(String input)

        Unescapes a string containing XML entity escapes to a string containing the actual Unicode characters corresponding to the escapes.

        Supports only the five basic XML entities (gt, lt, quot, amp, apos). Does not support DTDs or external entities.

        Note that numerical \\u Unicode codes are unescaped to their respective Unicode characters. This may change in future releases.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        a new unescaped String, null if null string input
        See Also:
        escapeXml10(String), escapeXml11(String)
      • escapeCsv

        public static final String escapeCsv​(String input)

        Returns a String value for a CSV column enclosed in double quotes, if required.

        If the value contains a comma, newline or double quote, then the String value is returned enclosed in double quotes.

        Any double quote characters in the value are escaped with another double quote.

        If the value does not contain a comma, newline or double quote, then the String value is returned unchanged.

        see Wikipedia and RFC 4180.
        Parameters:
        input - the input CSV column String, may be null
        Returns:
        the input String, enclosed in double quotes if the value contains a comma, newline or double quote, null if null string input
      • unescapeCsv

        public static final String unescapeCsv​(String input)

        Returns a String value for an unescaped CSV column.

        If the value is enclosed in double quotes, and contains a comma, newline or double quote, then quotes are removed.

        Any double quote escaped characters (a pair of double quotes) are unescaped to just one double quote.

        If the value is not enclosed in double quotes, or is and does not contain a comma, newline or double quote, then the String value is returned unchanged.

        see Wikipedia and RFC 4180.
        Parameters:
        input - the input CSV column String, may be null
        Returns:
        the input String, with enclosing double quotes removed and embedded double quotes unescaped, null if null string input
      • escapeXSI

        public static final String escapeXSI​(String input)

        Escapes the characters in a String using XSI rules.

        Beware! In most cases you don't want to escape shell commands but use multi-argument methods provided by ProcessBuilder or Runtime.exec(String[]) instead.

        Example:

         input string: He didn't say, "Stop!"
         output string: He\ didn\'t\ say,\ \"Stop!\"
         
        Parameters:
        input - String to escape values in, may be null
        Returns:
        String with escaped values, null if null string input
        See Also:
        Shell Command Language
      • unescapeXSI

        public static final String unescapeXSI​(String input)

        Unescapes the characters in a String using XSI rules.

        Parameters:
        input - the String to unescape, may be null
        Returns:
        a new unescaped String, null if null string input
        See Also:
        escapeXSI(String)