Java String Unescape unEscapeString(String str)

Description

Unescape commas in the string using the default escape char

License

Open Source License

Parameter

Parameter	Description
str	a string

Return

an unescaped string

Declaration

public static String unEscapeString(String str) 

Method Source Code

//package com.java2s;

public class Main {
    final public static char COMMA = ',';
    final public static char ESCAPE_CHAR = '\\';

    /**/*from www . ja va 2s  .  c o m*/
     * Unescape commas in the string using the default escape char
     * 
     * @param str
     *            a string
     * @return an unescaped string
     */
    public static String unEscapeString(String str) {
        return unEscapeString(str, ESCAPE_CHAR, COMMA);
    }

    /**
     * Unescape <code>charToEscape</code> in the string with the escape char <code>escapeChar</code>
     * 
     * @param str
     *            string
     * @param escapeChar
     *            escape char
     * @param charToEscape
     *            the escaped char
     * @return an unescaped string
     */
    public static String unEscapeString(String str, char escapeChar, char charToEscape) {
        return unEscapeString(str, escapeChar, new char[] { charToEscape });
    }

    /**
     * @param charsToEscape
     *            array of characters to unescape
     */
    public static String unEscapeString(String str, char escapeChar, char[] charsToEscape) {
        if (str == null) {
            return null;
        }
        StringBuilder result = new StringBuilder(str.length());
        boolean hasPreEscape = false;
        for (int i = 0; i < str.length(); i++) {
            char curChar = str.charAt(i);
            if (hasPreEscape) {
                if (curChar != escapeChar && !hasChar(charsToEscape, curChar)) {
                    // no special char
                    throw new IllegalArgumentException(
                            "Illegal escaped string " + str + " unescaped " + escapeChar + " at " + (i - 1));
                }
                // otherwise discard the escape char
                result.append(curChar);
                hasPreEscape = false;
            } else {
                if (hasChar(charsToEscape, curChar)) {
                    throw new IllegalArgumentException(
                            "Illegal escaped string " + str + " unescaped " + curChar + " at " + i);
                } else if (curChar == escapeChar) {
                    hasPreEscape = true;
                } else {
                    result.append(curChar);
                }
            }
        }
        if (hasPreEscape) {
            throw new IllegalArgumentException(
                    "Illegal escaped string " + str + ", not expecting " + escapeChar + " in the end.");
        }
        return result.toString();
    }

    private static boolean hasChar(char[] chars, char character) {
        for (char target : chars) {
            if (character == target) {
                return true;
            }
        }
        return false;
    }

    public static String toString(String[] content, String sign) {
        if (null == content) {
            return null;
        }

        sign = null == sign ? "," : sign;
        StringBuilder strBuilder = new StringBuilder();
        for (int i = 0; i < content.length; i++) {
            strBuilder.append(content[i]);
            if (i < content.length - 1) {
                strBuilder.append(sign);
            }
        }

        return strBuilder.toString();
    }
}

Related

1. unescapeString(String oldstr)
2. unescapeString(String s)
3. unescapeString(String s)
4. unescapeString(String s)
5. unescapeString(String s, char enclosed)
6. unEscapeString(String str)
7. unescapeString(String str)
8. unEscapeString(String str)
9. unescapeString(String string)