Java String Unescape unescape(String string)

Description

This method unescapes special characters in the given string.

License

Open Source License

Parameter

Parameter	Description
string	The string to unescape.

Return

A string with special characters unescaped.

Declaration

public static final String unescape(String string) 

Method Source Code

//package com.java2s;

public class Main {
    /**//from   ww w .ja  v  a 2s  . c  o  m
     * This method unescapes special characters in the given string.
     * @param string The string to unescape.
     * @return A string with special characters unescaped.
     */
    public static final String unescape(String string) {
        StringBuilder sb = new StringBuilder();
        boolean wasEscape = false;
        boolean unicode = false;
        int count = 0;
        for (char c : string.toCharArray()) {
            if (unicode) {
                sb.append(c);
                if (++count == 4) {
                    int s = sb.length() - 4;
                    String code = sb.substring(s);
                    sb.setLength(s);
                    try {
                        int ncode = Integer.parseInt(code, 16);
                        sb.append((char) ncode);
                    } catch (NumberFormatException e) {
                        sb.append("\\u");
                        sb.append(code);
                    }
                    unicode = false;
                }
            } else if (wasEscape) {
                switch (c) {
                case '0':
                    sb.append('\0');
                    break;
                case 'b':
                    sb.append('\b');
                    break;
                case 'f':
                    sb.append('\f');
                    break;
                case 't':
                    sb.append('\t');
                    break;
                case 'r':
                    sb.append('\r');
                    break;
                case 'n':
                    sb.append('\n');
                    break;
                case '\\':
                    sb.append('\\');
                    break;
                case '\'':
                    sb.append('\'');
                    break;
                case '"':
                    sb.append('"');
                    break;
                case 'u':
                    unicode = true;
                    count = 0;
                    break;
                default:
                    sb.append('\\');
                    sb.append(c);
                }
                wasEscape = false;
            } else if (c == '\\') {
                wasEscape = true;
            } else {
                sb.append(c);
            }
        }
        if (unicode) {
            int s = sb.length() - count;
            String code = sb.substring(s);
            sb.setLength(s);
            sb.append("\\u");
            sb.append(code);
        }
        if (wasEscape)
            sb.append('\\');
        return sb.toString();
    }
}

Related

1. unescape(String str)
2. unescape(String str)
3. unescape(String str)
4. unescape(String str, char escapeChar, char[] targetChars, char[] escapedChars)
5. unescape(String string)
6. unescape(String string)
7. unescape(String string)
8. unescape(String string)
9. unescape(String string, int escape)