java获取字符串MD5值

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

/**
 * 获取字符串MD5值
 * 
 * @author tangbincheng
 * 
 */
public class Str2MD5 {

	/**
	 * 获取字符串的16位md5值
	 * @param sourceStr
	 * @return
	 */
	public static String MD5_16(String sourceStr) {
		String md5 = MD5_32(sourceStr).substring(8, 24);
		return md5;
	}

	/**
	 * 获取字符串的32位md5值
	 * @param sourceStr
	 * @return
	 */
	public static String MD5_32(String sourceStr) {
		String result = "";
		try {
			MessageDigest md = MessageDigest.getInstance("MD5");
			md.update(sourceStr.getBytes());
			byte b[] = md.digest();
			int i;
			StringBuffer buf = new StringBuffer("");
			for (int offset = 0; offset < b.length; offset++) {
				i = b[offset];
				if (i < 0)
					i += 256;
				if (i < 16)
					buf.append("0");
				buf.append(Integer.toHexString(i));
			}
			result = buf.toString();
		} catch (NoSuchAlgorithmException e) {
			System.out.println(e);
		}
		return result;
	}
}