emailvalidation.java

这是一个用jsp+Oracle开发的联系人客户关系管理系统！

package com.ideas.parser;

import java.util.regex.*;

/*
 * Checks for invalid characters
 * in email addresses
 */
public class EmailValidation {
  public static void main(String[] args) throws Exception {

    String input = "[e-mail]";
//Checks for email addresses starting with
//inappropriate symbols like dots or @ signs.
    Pattern p = Pattern.compile("^\\.|^\\@");
    Matcher m = p.matcher(input);
    if (m.find()) {
      System.err.println("Email addresses don't start" +
                         " with dots or @ signs.");
//Checks for email addresses that start with
//www. and prints a message if it does.
    }
    p = Pattern.compile("^www\\.");
    m = p.matcher(input);
    if (m.find()) {
      System.out.println("Email addresses don't start" +
                         " with \"www.\", only web pages do.");
    }
    p = Pattern.compile("[^A-Za-z0-9\\.\\@_\\-~#]+");
    m = p.matcher(input);
    StringBuffer sb = new StringBuffer();
    boolean result = m.find();
    boolean deletedIllegalChars = false;

    while (result) {
      deletedIllegalChars = true;
      m.appendReplacement(sb, "");
      result = m.find();
    }

// Add the last segment of input to the new String
    m.appendTail(sb);

    input = sb.toString();

    if (deletedIllegalChars) {
      System.out.println("It contained incorrect characters" +
                         " , such as spaces or commas.");
    }
  }
}