java计算文本MD5值

java计算文本MD5值,用于加密

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


public class GetMd5 { 

	
	public static void main(String[] args) {
		String a="123";

	System.out.println(getMd5(a));	
	}

	/**
	 * 获取文本字段的MD5值
	 * @param txt
	 * @return
	 */
	public static String getMd5(String txt){
		String rs = "";
		String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "8","9", "a", "b", "c", "d", "e", "f" };
		try {
			MessageDigest messageDigest = MessageDigest.getInstance("MD5");
			byte[] b = messageDigest.digest(txt.getBytes());
			StringBuffer resultSb = new StringBuffer();
			for (int i = 0; i < b.length; i++) {
				int n = b[i];
				if (n < 0)
					n = 256 + n;
				int d1 = n / 16;
				int d2 = n % 16;
				resultSb.append(hexDigits[d1] + hexDigits[d2]);
			}
			rs = resultSb.toString();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		return rs;
	}
}

输出值:   202cb962ac59075b964b07152d234b70