一个检查email合法字符的问题

Question

org.apache.commons.validator.GenericValidator
这个里面有。

Answer 1

这个是它的源码。包含了org.apache.oro.text.perl.Perl5Util;这个你在找找看吧。
    /**
     * <p>Checks if a field has a valid e-mail address.</p>
     * <p>Based on a script by Sandeep V. Tamhankar ([email protected]), 
     * http://javascript.internet.com</p>
     *
     * @param  value  The value validation is being performed on.
    */
    public static boolean isEmail(String value) {
        boolean bValid = true;        try {
            String specialChars = "\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
            String validChars = "[^\\s" + specialChars + "]";
            String quotedUser = "(\"[^\"]*\")";
            String atom = validChars + '+';
            String word = "(" + atom + "|" + quotedUser + ")";            // Each pattern must be surrounded by /
            String legalAsciiPat = getDelimittedRegexp("^[\\000-\\177]+$");
            String emailPat = getDelimittedRegexp("^(.+)@(.+)$");
            String ipDomainPat =
                getDelimittedRegexp("^(\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})$");
            String userPat = getDelimittedRegexp("^" + word + "(\\." + word + ")*$");
            String domainPat =
                getDelimittedRegexp("^" + atom + "(\\." + atom + ")*$");
            String atomPat = getDelimittedRegexp("(" + atom + ")");            Perl5Util matchEmailPat = new Perl5Util();
            Perl5Util matchUserPat = new Perl5Util();
            Perl5Util matchIPPat = new Perl5Util();
            Perl5Util matchDomainPat = new Perl5Util();
            Perl5Util matchAtomPat = new Perl5Util();
            Perl5Util matchAsciiPat = new Perl5Util();            boolean ipAddress = false;
            boolean symbolic = false;            if (!matchAsciiPat.match(legalAsciiPat, value)) {
                return false;
            }            // Check the whole email address structure
            bValid = matchEmailPat.match(emailPat, value);            if (value.endsWith(".")) {
                bValid = false;
            }            // Check the user component of the email address
            if (bValid) {                String user = matchEmailPat.group(1);                // See if "user" is valid 
                bValid = matchUserPat.match(userPat, user);
            }            // Check the domain component of the email address
            if (bValid) {
                String domain = matchEmailPat.group(2);                // check if domain is IP address or symbolic
                ipAddress = matchIPPat.match(ipDomainPat, domain);                if (ipAddress) {
                    // this is an IP address so check components
                    for (int i = 1; i <= 4; i++) {
                        String ipSegment = matchIPPat.group(i);
                        if (ipSegment != null && ipSegment.length() > 0) {
                            int iIpSegment = 0;
                            try {
                                iIpSegment = Integer.parseInt(ipSegment);
                            } catch (Exception e) {
                                bValid = false;
                            }                            if (iIpSegment > 255) {
                                bValid = false;
                            }
                        } else {
                            bValid = false;
                        }
                    }
                } else {
                    // Domain is symbolic name
                    symbolic = matchDomainPat.match(domainPat, domain);
                }                if (symbolic) {
                    // this is a symbolic domain so check components
                    String[] domainSegment = new String[10];
                    boolean match = true;
                    int i = 0;
                    int l = 0;                    while (match) {
                        match = matchAtomPat.match(atomPat, domain);
                        if (match) {
                            domainSegment[i] = matchAtomPat.group(1);
                            l = domainSegment[i].length() + 1;
                            domain =
                                (l >= domain.length()) ? "" : domain.substring(l);
                            i++;
                        }
                    }                    int len = i;
                    if (domainSegment[len - 1].length() < 2
                        || domainSegment[len - 1].length() > 4) {
                        bValid = false;
                    }                    // Make sure there's a host name preceding the domain.
                    if (len < 2) {
                        bValid = false;
                    }                } else {
                    bValid = false;
                }
            }
        } catch (Exception e) {
            bValid = false;
        }        return bValid;
    }

Answer 2

才接触java和jsp不久，望请各位老大说明白点，谢谢了，先

Answer 3

用javascript 收集的好东西<script langauge="Javascript">
  // 如果输入值为空，函数返回false
function checkEmail(emailStr) {
               if (emailStr.length == 0) {
                   alert("Email地址不正确");
                   return false;
               }
               var emailPat=/^(.+)@(.+)$/;
               var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
               var validChars="\[^\\s" + specialChars + "\]";
               var quotedUser="(\"[^\"]*\")";
               var ipDomainPat=/^(\d{1,3})[.](\d{1,3})[.](\d{1,3})[.](\d{1,3})$/;
               var atom=validChars + '+';
               var word="(" + atom + "|" + quotedUser + ")";
               var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
               var domainPat=new RegExp("^" + atom + "(\\." + atom + ")*$");
               var matchArray=emailStr.match(emailPat);
               if (matchArray == null) {
                   alert("Email地址不正确");
                   return false;
               }
               var user=matchArray[1];
               var domain=matchArray[2];
               if (user.match(userPat) == null) {
                  alert("Email地址不正确"); 
                  return false;
               }
               var IPArray = domain.match(ipDomainPat);
               if (IPArray != null) {
                   for (var i = 1; i <= 4; i++) {
                      if (IPArray[i] > 255) {
                         alert("Email地址不正确");
                         return false;
                      }
                   }
                   return true;
               }
               var domainArray=domain.match(domainPat);
               if (domainArray == null) {
                     alert("Email地址不正确");
                     return false;
               }
               var atomPat=new RegExp(atom,"g");
               var domArr=domain.match(atomPat);
               var len=domArr.length;
               if ((domArr[domArr.length-1].length < 2) ||
                   (domArr[domArr.length-1].length > 3)) {
                   alert("Email地址不正确");
                   return false;
               }
               if (len < 2) {
                  alert("Email地址不正确"); 
                  return false;
               }
               return true;
            }
 </script>

Answer 4

好的，收到，但是有没有简单一点的，我只想用StringTokenizer去分割@,我的要求是在一个email地址中不会出现2个或2个以上的@,并且@两边不能有空格就行了，谢谢