java的正则表达式实例

用正则表达式检查邮箱和密码的实例。

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {

	/**
	 * @param args
	 * @throws IOException
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		String ln;
		BufferedReader rd = new BufferedReader(new InputStreamReader(System.in));
		while ((ln = rd.readLine()) != null) {
			boolean psswd, email;
			psswd = isLegalPassword(ln);
			email = isValidEmail(ln);
			System.out.println("input=<" + ln + "> passwd? " + psswd
					+ ", email? " + email);
		}
	}

	static boolean isValidEmail(String email) {
		String regex = "([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((\\.[a-zA-Z0-9_-]{2,3}){1,2})";
		Pattern pattern = Pattern.compile(regex);
		Matcher mat = pattern.matcher(email);
		return mat.matches();
	}

	static boolean isLegalPassword(String pswd) {
		boolean ret = false;

		String ftmt = "[0-9a-zA-Z_]{5,10}";
		Pattern pattern = Pattern.compile(ftmt);
		Matcher mat = pattern.matcher(pswd);
		ret = mat.matches();
		return ret;
	}
}

 

参考http://outofmemory.cn/code-snippet/1255/java-regular-expression-review-string-shifou-match