mailaddress.java

java 开发的邮件服务器平台。支持以下协议。 协议可以修改为自己的专门标识

     */
    public int hashCode() {
        return toString().toLowerCase(Locale.US).hashCode();
    }

    private String parseQuotedLocalPart(String address) throws ParseException {
        StringBuffer resultSB = new StringBuffer();
        resultSB.append('\"');
        pos++;
        //<quoted-string> ::=  """ <qtext> """
        //<qtext> ::=  "\" <x> | "\" <x> <qtext> | <q> | <q> <qtext>
        while (true) {
            if (address.charAt(pos) == '\"') {
                resultSB.append('\"');
                //end of quoted string... move forward
                pos++;
                break;
            }
            if (address.charAt(pos) == '\\') {
                resultSB.append('\\');
                pos++;
                //<x> ::= any one of the 128 ASCII characters (no exceptions)
                char x = address.charAt(pos);
                if (x < 0 || x > 127) {
                    throw new ParseException("Invalid \\ syntaxed character at position " + (pos + 1));
                }
                resultSB.append(x);
                pos++;
            } else {
                //<q> ::= any one of the 128 ASCII characters except <CR>,
                //<LF>, quote ("), or backslash (\)
                char q = address.charAt(pos);
                if (q <= 0 || q == '\n' || q == '\r' || q == '\"' || q == '\\') {
                    throw new ParseException("Unquoted local-part (user account) must be one of the 128 ASCI characters exception <CR>, <LF>, quote (\"), or backslash (\\) at position " + (pos + 1));
                }
                resultSB.append(q);
                pos++;
            }
        }
        return resultSB.toString();
    }

    private String parseUnquotedLocalPart(String address) throws ParseException {
        StringBuffer resultSB = new StringBuffer();
        //<dot-string> ::= <string> | <string> "." <dot-string>
        boolean lastCharDot = false;
        while (true) {
            //<string> ::= <char> | <char> <string>
            //<char> ::= <c> | "\" <x>
            if (address.charAt(pos) == '\\') {
                resultSB.append('\\');
                pos++;
                //<x> ::= any one of the 128 ASCII characters (no exceptions)
                char x = address.charAt(pos);
                if (x < 0 || x > 127) {
                    throw new ParseException("Invalid \\ syntaxed character at position " + (pos + 1));
                }
                resultSB.append(x);
                pos++;
                lastCharDot = false;
            } else if (address.charAt(pos) == '.') {
                resultSB.append('.');
                pos++;
                lastCharDot = true;
            } else if (address.charAt(pos) == '@') {
                //End of local-part
                break;
            } else {
                //<c> ::= any one of the 128 ASCII characters, but not any
                //    <special> or <SP>
                //<special> ::= "<" | ">" | "(" | ")" | "[" | "]" | "\" | "."
                //    | "," | ";" | ":" | "@"  """ | the control
                //    characters (ASCII codes 0 through 31 inclusive and
                //    127)
                //<SP> ::= the space character (ASCII code 32)
                char c = address.charAt(pos);
                if (c <= 31 || c >= 127 || c == ' ') {
                    throw new ParseException("Invalid character in local-part (user account) at position " + (pos + 1));
                }
                for (int i = 0; i < SPECIAL.length; i++) {
                    if (c == SPECIAL[i]) {
                        throw new ParseException("Invalid character in local-part (user account) at position " + (pos + 1));
                    }
                }
                resultSB.append(c);
                pos++;
                lastCharDot = false;
            }
        }
        if (lastCharDot) {
            throw new ParseException("local-part (user account) ended with a \".\", which is invalid.");
        }
        return resultSB.toString();
    }

    private String parseNumber(String address) throws ParseException {
        //<number> ::= <d> | <d> <number>

        StringBuffer resultSB = new StringBuffer();
        //We keep the position from the class level pos field
        while (true) {
            if (pos >= address.length()) {
                break;
            }
            //<d> ::= any one of the ten digits 0 through 9
            char d = address.charAt(pos);
            if (d == '.') {
                break;
            }
            if (d < '0' || d > '9') {
                throw new ParseException("In domain, did not find a number in # address at position " + (pos + 1));
            }
            resultSB.append(d);
            pos++;
        }
        return resultSB.toString();
    }

    private String parseDotNum(String address) throws ParseException {
        //throw away all irrelevant '\' they're not necessary for escaping of '.' or digits, and are illegal as part of the domain-literal
        while(address.indexOf("\\")>-1){
             address= address.substring(0,address.indexOf("\\")) + address.substring(address.indexOf("\\")+1);
        }
        StringBuffer resultSB = new StringBuffer();
        //we were passed the string with pos pointing the the [ char.
        // take the first char ([), put it in the result buffer and increment pos
        resultSB.append(address.charAt(pos));
        pos++;

        //<dotnum> ::= <snum> "." <snum> "." <snum> "." <snum>
        for (int octet = 0; octet < 4; octet++) {
            //<snum> ::= one, two, or three digits representing a decimal
            //                      integer value in the range 0 through 255
            //<d> ::= any one of the ten digits 0 through 9
            StringBuffer snumSB = new StringBuffer();
            for (int digits = 0; digits < 3; digits++) {
                char d = address.charAt(pos);
                if (d == '.') {
                    break;
                }
                if (d == ']') {
                    break;
                }
                if (d < '0' || d > '9') {
                    throw new ParseException("Invalid number at position " + (pos + 1));
                }
                snumSB.append(d);
                pos++;
            }
            if (snumSB.toString().length() == 0) {
                throw new ParseException("Number not found at position " + (pos + 1));
            }
            try {
                int snum = Integer.parseInt(snumSB.toString());
                if (snum > 255) {
                    throw new ParseException("Invalid number at position " + (pos + 1));
                }
            } catch (NumberFormatException nfe) {
                throw new ParseException("Invalid number at position " + (pos + 1));
            }
            resultSB.append(snumSB.toString());
            if (address.charAt(pos) == ']') {
                if (octet < 3) {
                    throw new ParseException("End of number reached too quickly at " + (pos + 1));
                } else {
                    break;
                }
            }
            if (address.charAt(pos) == '.') {
                resultSB.append('.');
                pos++;
            }
        }
        if (address.charAt(pos) != ']') {
            throw new ParseException("Did not find closing bracket \"]\" in domain at position " + (pos + 1));
        }
        resultSB.append(']');
        pos++;
        return resultSB.toString();
    }

    private String parseDomainName(String address) throws ParseException {
        StringBuffer resultSB = new StringBuffer();
        //<name> ::= <a> <ldh-str> <let-dig>
        //<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
        //<let-dig> ::= <a> | <d>
        //<let-dig-hyp> ::= <a> | <d> | "-"
        //<a> ::= any one of the 52 alphabetic characters A through Z
        //  in upper case and a through z in lower case
        //<d> ::= any one of the ten digits 0 through 9

        // basically, this is a series of letters, digits, and hyphens,
        // but it can't start with a digit or hypthen
        // and can't end with a hyphen

        // in practice though, we should relax this as domain names can start
        // with digits as well as letters.  So only check that doesn't start
        // or end with hyphen.
        while (true) {
            if (pos >= address.length()) {
                break;
            }
            char ch = address.charAt(pos);
            if ((ch >= '0' && ch <= '9') || 
                (ch >= 'a' && ch <= 'z') || 
                (ch >= 'A' && ch <= 'Z') ||
                (ch == '-')) {
                resultSB.append(ch);
                pos++;
                continue;
            }
            if (ch == '.') {
                break;
            }
            throw new ParseException("Invalid character at " + pos);
        }
        String result = resultSB.toString();
        if (result.startsWith("-") || result.endsWith("-")) {
            throw new ParseException("Domain name cannot begin or end with a hyphen \"-\" at position " + (pos + 1));
        }
        return result;
    }
}