package common;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class GetEmail {

?public static int MAXEMAILLEN = 256;
?
?/**
? * 從指定的字符串中提取Email
? *
? */
?public static String parse(String content) {
??String email = null;
??if (content==null || content.length()<1) {
???return email;
??}
??//找出含有@
??int beginPos;
??int i;
??String token = "@";
??String preHalf="";
??String sufHalf = "";
??
??beginPos = content.indexOf(token);
??if (beginPos>-1) {
???//前項掃描
???String s = null;
???i= beginPos;
???while(i>0) {
????s = content.substring(i-1,i);
????if (isLetter(s))
?????preHalf = s+preHalf;
????else
?????break;
????i--;
???}
???//后項掃描
???i= beginPos+1;
???while( i<content.length()) {
????s = content.substring(i,i+1);
????if (isLetter(s))
?????sufHalf =? sufHalf +s;
????else
?????break;
????i++;??
???}
???//判斷合法性
???email = preHalf + "@" + sufHalf;
???if (email.length()>MAXEMAILLEN) {
????return null;
???}
??}
??return email;
?}
?/**
? * 判斷是不是合法Email
? *
? */
?public static String isEmail(String email) {
??try {
???
???if (email==null || email.length()<1) {
????return null;
???}
???String check = "^([0-9a-zA-Z]+[_.0-9a-zA-Z-]+)@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2,3})$";
???Pattern regex = Pattern.compile(check);
???Matcher matcher = regex.matcher(email);
???boolean isMatched = matcher.matches();
???if(isMatched) {
????return email;
???} else {
????return null;
???}
??} catch (RuntimeException e) {
???return null;
??}
?}
?/**
? * 判斷是不是合法字符
? *
? */
?public static boolean isLetter(String c) {
??boolean result = false;
??
??if (c==null || c.length()<0)
???return false;
??//a-z?
??if (c.compareToIgnoreCase("a")>=0 && c.compareToIgnoreCase("z")<=0)
???return true;
??//0-9
??if (c.compareToIgnoreCase("0")>=0 && c.compareToIgnoreCase("9")<=0)
???return true;
??//. - _
??if (c.equals(".") || c.equals("-") || c.equals("_") )
???return true;

??return result;?
?}?
}