Encoding html in java

Содержание

Class URLEncoder
Method Summary
Methods declared in class java.lang.Object
Method Details
encode
encode
encode
Java Escape HTML – Encode String to HTML
Class URLEncoder
Method Summary
Methods declared in class java.lang.Object
Method Details
encode
encode
encode

Class URLEncoder

Utility class for HTML form encoding. This class contains static methods for converting a String to the application/x-www-form-urlencoded MIME format. For more information about HTML form encoding, consult the HTML specification.

The alphanumeric characters » a » through » z «, » A » through » Z » and » 0 » through » 9 » remain the same.
The special characters » . «, » — «, » * «, and » _ » remain the same.
The space character » » is converted into a plus sign » + «.
All other characters are unsafe and are first converted into one or more bytes using some encoding scheme. Then each byte is represented by the 3-character string » %xy «, where xy is the two-digit hexadecimal representation of the byte. The recommended encoding scheme to use is UTF-8. However, for compatibility reasons, if an encoding is not specified, then the default charset is used.

For example using UTF-8 as the encoding scheme the string «The string ü@foo-bar» would get converted to «The+string+%C3%BC%40foo-bar» because in UTF-8 the character ü is encoded as two bytes C3 (hex) and BC (hex), and the character @ is encoded as one byte 40 (hex).

Method Summary

Methods declared in class java.lang.Object

Method Details

encode

The resulting string may vary depending on the default charset. Instead, use the encode(String,String) method to specify the encoding.

Translates a string into x-www-form-urlencoded format. This method uses the default charset as the encoding scheme to obtain the bytes for unsafe characters.

encode

Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme. This method behaves the same as encode(String s, Charset charset) except that it will look up the charset using the given encoding name.

encode

Translates a string into application/x-www-form-urlencoded format using a specific Charset. This method uses the supplied charset to obtain the bytes for unsafe characters. Note: The World Wide Web Consortium Recommendation states that UTF-8 should be used. Not doing so may introduce incompatibilities.

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Java Escape HTML – Encode String to HTML

Java examples of escaping the characters in a String using HTML entities. The encoding process converts a Java String to equivalent HTML content browsers can print.

1. Using StringEscapeUtils.escapeHtml4()

The StringEscapeUtils class is part of Apache common-text library. It takes a raw string as a parameter and then escapes the characters using HTML entities. It supports all known HTML 4.0 entities.

Note that Apostrophe escape character (') is not a legal entity and so is not supported.

To use StringEscapeUtils , import the lastest version of commons-text dependency.

 org.apache.commons commons-text 1.4

Now we use StringEscapeUtils.escapeHtml4() method as follows:

String unEscapedString ; String escapedHTML = StringEscapeUtils.escapeHtml4(unEscapedString); System.out.println(escapedHTML); //Browser can now parse this and print

<java>public static void main(String[] args) < . ></java>

2. Custom StringUtils.encodeHtml()

If we have certain requirements where we need to modify the logic provided by library methods, the we can write our own method. Mostly this approach should be avoided, but it may be handy when requirements arises.

String unEscapedString ; String escapedHTML = StringUtils.encodeHtml(unEscapedString); System.out.println(escapedHTML); //Browser can now parse this and print

The StringUtils class is as follows. We can add, modify or remove entries from the htmlEncodeChars map to customize the behavior of the encoding function.

import java.util.HashMap; public class StringUtils < private static final HashMaphtmlEncodeChars = new HashMap<>(); static < // Special characters for HTML htmlEncodeChars.put('\u0026', "&"); htmlEncodeChars.put('\u003C', "<"); htmlEncodeChars.put('\u003E', ">"); htmlEncodeChars.put('\u0022', """); htmlEncodeChars.put('\u0152', "Œ"); htmlEncodeChars.put('\u0153', "œ"); htmlEncodeChars.put('\u0160', "Š"); htmlEncodeChars.put('\u0161', "š"); htmlEncodeChars.put('\u0178', "Ÿ"); htmlEncodeChars.put('\u02C6', "ˆ"); htmlEncodeChars.put('\u02DC', "˜"); htmlEncodeChars.put('\u2002', " "); htmlEncodeChars.put('\u2003', " "); htmlEncodeChars.put('\u2009', " "); htmlEncodeChars.put('\u200C', "‌"); htmlEncodeChars.put('\u200D', "‍"); htmlEncodeChars.put('\u200E', "‎"); htmlEncodeChars.put('\u200F', "‏"); htmlEncodeChars.put('\u2013', "–"); htmlEncodeChars.put('\u2014', "—"); htmlEncodeChars.put('\u2018', "‘"); htmlEncodeChars.put('\u2019', "’"); htmlEncodeChars.put('\u201A', "‚"); htmlEncodeChars.put('\u201C', "“"); htmlEncodeChars.put('\u201D', "”"); htmlEncodeChars.put('\u201E', "„"); htmlEncodeChars.put('\u2020', "†"); htmlEncodeChars.put('\u2021', "‡"); htmlEncodeChars.put('\u2030', "‰"); htmlEncodeChars.put('\u2039', "‹"); htmlEncodeChars.put('\u203A', "›"); htmlEncodeChars.put('\u20AC', "€"); // Character entity references for ISO 8859-1 characters htmlEncodeChars.put('\u00A0', " "); htmlEncodeChars.put('\u00A1', "¡"); htmlEncodeChars.put('\u00A2', "¢"); htmlEncodeChars.put('\u00A3', "£"); htmlEncodeChars.put('\u00A4', "¤"); htmlEncodeChars.put('\u00A5', "¥"); htmlEncodeChars.put('\u00A6', "¦"); htmlEncodeChars.put('\u00A7', "§"); htmlEncodeChars.put('\u00A8', "¨"); htmlEncodeChars.put('\u00A9', "©"); htmlEncodeChars.put('\u00AA', "ª"); htmlEncodeChars.put('\u00AB', "«"); htmlEncodeChars.put('\u00AC', "¬"); htmlEncodeChars.put('\u00AD', ""); htmlEncodeChars.put('\u00AE', "®"); htmlEncodeChars.put('\u00AF', "¯"); htmlEncodeChars.put('\u00B0', "°"); htmlEncodeChars.put('\u00B1', "±"); htmlEncodeChars.put('\u00B2', "²"); htmlEncodeChars.put('\u00B3', "³"); htmlEncodeChars.put('\u00B4', "´"); htmlEncodeChars.put('\u00B5', "µ"); htmlEncodeChars.put('\u00B6', "¶"); htmlEncodeChars.put('\u00B7', "·"); htmlEncodeChars.put('\u00B8', "¸"); htmlEncodeChars.put('\u00B9', "¹"); htmlEncodeChars.put('\u00BA', "º"); htmlEncodeChars.put('\u00BB', "»"); htmlEncodeChars.put('\u00BC', "¼"); htmlEncodeChars.put('\u00BD', "½"); htmlEncodeChars.put('\u00BE', "¾"); htmlEncodeChars.put('\u00BF', "¿"); htmlEncodeChars.put('\u00C0', "À"); htmlEncodeChars.put('\u00C1', "Á"); htmlEncodeChars.put('\u00C2', "Â"); htmlEncodeChars.put('\u00C3', "Ã"); htmlEncodeChars.put('\u00C4', "Ä"); htmlEncodeChars.put('\u00C5', "Å"); htmlEncodeChars.put('\u00C6', "Æ"); htmlEncodeChars.put('\u00C7', "Ç"); htmlEncodeChars.put('\u00C8', "È"); htmlEncodeChars.put('\u00C9', "É"); htmlEncodeChars.put('\u00CA', "Ê"); htmlEncodeChars.put('\u00CB', "Ë"); htmlEncodeChars.put('\u00CC', "Ì"); htmlEncodeChars.put('\u00CD', "Í"); htmlEncodeChars.put('\u00CE', "Î"); htmlEncodeChars.put('\u00CF', "Ï"); htmlEncodeChars.put('\u00D0', "Ð"); htmlEncodeChars.put('\u00D1', "Ñ"); htmlEncodeChars.put('\u00D2', "Ò"); htmlEncodeChars.put('\u00D3', "Ó"); htmlEncodeChars.put('\u00D4', "Ô"); htmlEncodeChars.put('\u00D5', "Õ"); htmlEncodeChars.put('\u00D6', "Ö"); htmlEncodeChars.put('\u00D7', "×"); htmlEncodeChars.put('\u00D8', "Ø"); htmlEncodeChars.put('\u00D9', "Ù"); htmlEncodeChars.put('\u00DA', "Ú"); htmlEncodeChars.put('\u00DB', "Û"); htmlEncodeChars.put('\u00DC', "Ü"); htmlEncodeChars.put('\u00DD', "Ý"); htmlEncodeChars.put('\u00DE', "Þ"); htmlEncodeChars.put('\u00DF', "ß"); htmlEncodeChars.put('\u00E0', "à"); htmlEncodeChars.put('\u00E1', "á"); htmlEncodeChars.put('\u00E2', "â"); htmlEncodeChars.put('\u00E3', "ã"); htmlEncodeChars.put('\u00E4', "ä"); htmlEncodeChars.put('\u00E5', "å"); htmlEncodeChars.put('\u00E6', "æ"); htmlEncodeChars.put('\u00E7', "ç"); htmlEncodeChars.put('\u00E8', "è"); htmlEncodeChars.put('\u00E9', "é"); htmlEncodeChars.put('\u00EA', "ê"); htmlEncodeChars.put('\u00EB', "ë"); htmlEncodeChars.put('\u00EC', "ì"); htmlEncodeChars.put('\u00ED', "í"); htmlEncodeChars.put('\u00EE', "î"); htmlEncodeChars.put('\u00EF', "ï"); htmlEncodeChars.put('\u00F0', "ð"); htmlEncodeChars.put('\u00F1', "ñ"); htmlEncodeChars.put('\u00F2', "ò"); htmlEncodeChars.put('\u00F3', "ó"); htmlEncodeChars.put('\u00F4', "ô"); htmlEncodeChars.put('\u00F5', "õ"); htmlEncodeChars.put('\u00F6', "ö"); htmlEncodeChars.put('\u00F7', "÷"); htmlEncodeChars.put('\u00F8', "ø"); htmlEncodeChars.put('\u00F9', "ù"); htmlEncodeChars.put('\u00FA', "ú"); htmlEncodeChars.put('\u00FB', "û"); htmlEncodeChars.put('\u00FC', "ü"); htmlEncodeChars.put('\u00FD', "ý"); htmlEncodeChars.put('\u00FE', "þ"); htmlEncodeChars.put('\u00FF', "ÿ"); // Mathematical, Greek and Symbolic characters for HTML htmlEncodeChars.put('\u0192', "ƒ"); htmlEncodeChars.put('\u0391', "Α"); htmlEncodeChars.put('\u0392', "Β"); htmlEncodeChars.put('\u0393', "Γ"); htmlEncodeChars.put('\u0394', "Δ"); htmlEncodeChars.put('\u0395', "Ε"); htmlEncodeChars.put('\u0396', "Ζ"); htmlEncodeChars.put('\u0397', "Η"); htmlEncodeChars.put('\u0398', "Θ"); htmlEncodeChars.put('\u0399', "Ι"); htmlEncodeChars.put('\u039A', "Κ"); htmlEncodeChars.put('\u039B', "Λ"); htmlEncodeChars.put('\u039C', "Μ"); htmlEncodeChars.put('\u039D', "Ν"); htmlEncodeChars.put('\u039E', "Ξ"); htmlEncodeChars.put('\u039F', "Ο"); htmlEncodeChars.put('\u03A0', "Π"); htmlEncodeChars.put('\u03A1', "Ρ"); htmlEncodeChars.put('\u03A3', "Σ"); htmlEncodeChars.put('\u03A4', "Τ"); htmlEncodeChars.put('\u03A5', "Υ"); htmlEncodeChars.put('\u03A6', "Φ"); htmlEncodeChars.put('\u03A7', "Χ"); htmlEncodeChars.put('\u03A8', "Ψ"); htmlEncodeChars.put('\u03A9', "Ω"); htmlEncodeChars.put('\u03B1', "α"); htmlEncodeChars.put('\u03B2', "β"); htmlEncodeChars.put('\u03B3', "γ"); htmlEncodeChars.put('\u03B4', "δ"); htmlEncodeChars.put('\u03B5', "ε"); htmlEncodeChars.put('\u03B6', "ζ"); htmlEncodeChars.put('\u03B7', "η"); htmlEncodeChars.put('\u03B8', "θ"); htmlEncodeChars.put('\u03B9', "ι"); htmlEncodeChars.put('\u03BA', "κ"); htmlEncodeChars.put('\u03BB', "λ"); htmlEncodeChars.put('\u03BC', "μ"); htmlEncodeChars.put('\u03BD', "ν"); htmlEncodeChars.put('\u03BE', "ξ"); htmlEncodeChars.put('\u03BF', "ο"); htmlEncodeChars.put('\u03C0', "π"); htmlEncodeChars.put('\u03C1', "ρ"); htmlEncodeChars.put('\u03C2', "ς"); htmlEncodeChars.put('\u03C3', "σ"); htmlEncodeChars.put('\u03C4', "τ"); htmlEncodeChars.put('\u03C5', "υ"); htmlEncodeChars.put('\u03C6', "φ"); htmlEncodeChars.put('\u03C7', "χ"); htmlEncodeChars.put('\u03C8', "ψ"); htmlEncodeChars.put('\u03C9', "ω"); htmlEncodeChars.put('\u03D1', "ϑ"); htmlEncodeChars.put('\u03D2', "ϒ"); htmlEncodeChars.put('\u03D6', "ϖ"); htmlEncodeChars.put('\u2022', "•"); htmlEncodeChars.put('\u2026', "…"); htmlEncodeChars.put('\u2032', "′"); htmlEncodeChars.put('\u2033', "″"); htmlEncodeChars.put('\u203E', "‾"); htmlEncodeChars.put('\u2044', "⁄"); htmlEncodeChars.put('\u2118', "℘"); htmlEncodeChars.put('\u2111', "ℑ"); htmlEncodeChars.put('\u211C', "ℜ"); htmlEncodeChars.put('\u2122', "™"); htmlEncodeChars.put('\u2135', "ℵ"); htmlEncodeChars.put('\u2190', "←"); htmlEncodeChars.put('\u2191', "↑"); htmlEncodeChars.put('\u2192', "→"); htmlEncodeChars.put('\u2193', "↓"); htmlEncodeChars.put('\u2194', "↔"); htmlEncodeChars.put('\u21B5', "↵"); htmlEncodeChars.put('\u21D0', "⇐"); htmlEncodeChars.put('\u21D1', "⇑"); htmlEncodeChars.put('\u21D2', "⇒"); htmlEncodeChars.put('\u21D3', "⇓"); htmlEncodeChars.put('\u21D4', "⇔"); htmlEncodeChars.put('\u2200', "∀"); htmlEncodeChars.put('\u2202', "∂"); htmlEncodeChars.put('\u2203', "∃"); htmlEncodeChars.put('\u2205', "∅"); htmlEncodeChars.put('\u2207', "∇"); htmlEncodeChars.put('\u2208', "∈"); htmlEncodeChars.put('\u2209', "∉"); htmlEncodeChars.put('\u220B', "∋"); htmlEncodeChars.put('\u220F', "∏"); htmlEncodeChars.put('\u2211', "∑"); htmlEncodeChars.put('\u2212', "−"); htmlEncodeChars.put('\u2217', "∗"); htmlEncodeChars.put('\u221A', "√"); htmlEncodeChars.put('\u221D', "∝"); htmlEncodeChars.put('\u221E', "∞"); htmlEncodeChars.put('\u2220', "∠"); htmlEncodeChars.put('\u2227', "∧"); htmlEncodeChars.put('\u2228', "∨"); htmlEncodeChars.put('\u2229', "∩"); htmlEncodeChars.put('\u222A', "∪"); htmlEncodeChars.put('\u222B', "∫"); htmlEncodeChars.put('\u2234', "∴"); htmlEncodeChars.put('\u223C', "∼"); htmlEncodeChars.put('\u2245', "≅"); htmlEncodeChars.put('\u2248', "≈"); htmlEncodeChars.put('\u2260', "≠"); htmlEncodeChars.put('\u2261', "≡"); htmlEncodeChars.put('\u2264', "≤"); htmlEncodeChars.put('\u2265', "≥"); htmlEncodeChars.put('\u2282', "⊂"); htmlEncodeChars.put('\u2283', "⊃"); htmlEncodeChars.put('\u2284', "⊄"); htmlEncodeChars.put('\u2286', "⊆"); htmlEncodeChars.put('\u2287', "⊇"); htmlEncodeChars.put('\u2295', "⊕"); htmlEncodeChars.put('\u2297', "⊗"); htmlEncodeChars.put('\u22A5', "⊥"); htmlEncodeChars.put('\u22C5', "⋅"); htmlEncodeChars.put('\u2308', "⌈"); htmlEncodeChars.put('\u2309', "⌉"); htmlEncodeChars.put('\u230A', "⌊"); htmlEncodeChars.put('\u230B', "⌋"); htmlEncodeChars.put('\u2329', "⟨"); htmlEncodeChars.put('\u232A', "⟩"); htmlEncodeChars.put('\u25CA', "◊"); htmlEncodeChars.put('\u2660', "♠"); htmlEncodeChars.put('\u2663', "♣"); htmlEncodeChars.put('\u2665', "♥"); htmlEncodeChars.put('\u2666', "♦"); >public static String encodeHtml(String source) < return encode(source, htmlEncodeChars); >private static String encode(String source, HashMap encodingTable) < if (null == source) < return null; >if (null == encodingTable) < return source; >StringBuffer encoded_string = null; char[] string_to_encode_array = source.toCharArray(); int last_match = -1; int difference = 0; for (int i = 0; i < string_to_encode_array.length; i++) < char char_to_encode = string_to_encode_array[i]; if (encodingTable.containsKey(char_to_encode)) < if (null == encoded_string) < encoded_string = new StringBuffer(source.length()); >difference = i - (last_match + 1); if (difference > 0) < encoded_string.append(string_to_encode_array, last_match + 1, difference); >encoded_string.append(encodingTable.get(char_to_encode)); last_match = i; > > if (null == encoded_string) < return source; >else < difference = string_to_encode_array.length - (last_match + 1); if (difference >0) < encoded_string.append(string_to_encode_array, last_match + 1, difference); >return encoded_string.toString(); > > >

Источник

Class URLEncoder

The alphanumeric characters » a » through » z «, » A » through » Z » and » 0 » through » 9 » remain the same.
The special characters » . «, » — «, » * «, and » _ » remain the same.
The space character » » is converted into a plus sign » + «.
All other characters are unsafe and are first converted into one or more bytes using some encoding scheme. Then each byte is represented by the 3-character string » %xy «, where xy is the two-digit hexadecimal representation of the byte. The recommended encoding scheme to use is UTF-8. However, for compatibility reasons, if an encoding is not specified, then the default charset is used.

Method Summary

Methods declared in class java.lang.Object

Method Details

encode

The resulting string may vary depending on the default charset. Instead, use the encode(String,String) method to specify the encoding.

Translates a string into x-www-form-urlencoded format. This method uses the default charset as the encoding scheme to obtain the bytes for unsafe characters.

encode

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