java 驗證郵箱格式怎么實現(xiàn)

public class Test{

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public static void main(String[] args){

Test t = new Test();

String email = "test@sina.com" ;

boolean isEmail = t.isEmail(email);

if(isEmail){

System.out.println(email +" is a right email!!!");

}else{

System.out.println("error");

}

}

public boolean isEmail(String email){

//正則表達式

/*

String regex = "^[A-Za-z]{1,40}@[A-Za-z0-9]{1,40}\\.[A-Za-z]{2,3}$";

return email.matches(regex);

*/

//不適用正則

if(email==null||"".equals(email)) return false ;

if(!containsOneWord('@',email)||!containsOneWord('.',email)) return false;

String prefix = email.substring(0,email.indexOf("@"));

String middle = email.substring(email.indexOf("@")+1,email.indexOf("."));

String subfix = email.substring(email.indexOf(".")+1);

System.out.println("prefix="+prefix +" middle="+middle+" subfix="+subfix);

if(prefix==null||prefix.length()40||prefix.length()==0) return false ;

if(!isAllWords(prefix)) return false ;

if(middle==null||middle.length()40||middle.length()==0) return false ;

if(!isAllWordsAndNo(middle)) return false ;

if(subfix==null||subfix.length()3||subfix.length()2) return false ;

if(!isAllWords(subfix)) return false ;

return true ;

}

//判斷字符串只包含指定的一個字符c

private boolean containsOneWord(char c , String word){

char[] array = word.toCharArray();

int count = 0 ;

for(Character ch : array){

if(c == ch) {

count++;

}

}

return count==1 ;

}

//檢查一個字符串是否全部是字母

private boolean isAllWords(String prefix){

char[] array = prefix.toCharArray();

for(Character ch : array){

if(ch'A' || ch'z' || (ch'a' ch'Z')) return false ;

}

return true;

}

//檢查一個字符串是否包含字母和數(shù)字

private boolean isAllWordsAndNo(String middle){

char[] array = middle.toCharArray();

for(Character ch : array){

if(ch'0' || ch 'z') return false ;

else if(ch '9' ch 'A') return false ;

else if(ch 'Z' ch 'a') return false ;

}

return true ;

}

}

java如何驗證一個email地址是否真實有效。

首先使用java提供的格式類判斷email是否格式有誤，然后使用開源框架，驗證郵箱是否有用，示例如下：

public?static?boolean?checkEmail(String?email)?{

if?(!email.matches("[\\w\\.\\-]+@([\\w\\-]+\\.)+[\\w\\-]+"))?{

return?false;

}

String?host?=?"";

String?hostName?=?email.split("@")[1];

Record[]?result?=?null;

SMTPClient?client?=?new?SMTPClient();

try?{

//?查找MX記錄

Lookup?lookup?=?new?Lookup(hostName,?Type.MX);

lookup.run();

if?(lookup.getResult()?!=?Lookup.SUCCESSFUL)?{

return?false;

}?else?{

result?=?lookup.getAnswers();

}

//?連接到郵箱服務(wù)器

for?(int?i?=?0;?i??result.length;?i++)?{

host?=?result[i].getAdditionalName().toString();

client.connect(host);

if?(!SMTPReply.isPositiveCompletion(client.getReplyCode()))?{

client.disconnect();

continue;

}?else?{

break;

}

}

//以下2項自己填寫快速的，有效的郵箱

client.login("163.com");

client.setSender("sxgkwei@163.com");

client.addRecipient(email);

if?(250?==?client.getReplyCode())?{

return?true;

}

}?catch?(Exception?e)?{

e.printStackTrace();

}?finally?{

try?{

client.disconnect();

}?catch?(IOException?e)?{

}

}

return?false;

}

需要的jar支持：commons-net-2.2.jar，dnsjava-2.1.1.jar

JAVA 用流實現(xiàn)郵箱驗證

郵箱驗證的實現(xiàn)，不過是用正則表達式子實現(xiàn)的，能夠滿足你上面提出的7條要求 String email = "dfbv423@163.com"; Pattern pattern = Pattern .compile("^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$"); Matcher matcher = pattern.matcher(email); if (true == matcher.matches()) { if (email.indexOf("@163.com") 0) System.out.println("是網(wǎng)易郵箱"); else System.out.println("不是網(wǎng)易郵箱"); } else System.out.println("根本就不是郵箱"); }