java中实现 MD5加密算法加密用户密码

package tools;
/* * 创建日期 2005-8-15 * MD5 */
import java.security.MessageDigest;

public class StringUtil {
private final static String[] hexDigits = {
"0", "1", "2", "3", "4", "5", "6", "7",
"8", "9", "a", "b", "c", "d", "e", "f"};
/**
*
* 转换字节数组为16进制字串
* @param b 字节数组
* * @return 16进制字串
* */
public static String byteArrayToHexString(byte[] b) {
StringBuffer resultSb = new StringBuffer();
for (int i = 0; i < b.length; i++) {
resultSb.append(byteToHexString(b[i]));
}
return resultSb.toString();
}
private static String byteToHexString(byte b) {
int n = b;
int d1 = 0;
int d2 = 0;
if (n < 0){
n = 256 + n;
d1 = n / 16;
d2 = n % 16;

}
return hexDigits[d1] + hexDigits[d2];
}
public static String MD5Encode(String origin) {
String resultString = null;
try {
resultString=new String(origin);
MessageDigest md = MessageDigest.getInstance("MD5");
resultString=byteArrayToHexString(md.digest(resultString.getBytes()));
}catch (Exception ex) {

}
return resultString;
}
/*
public static void main(String[] args){
System.err.println(MD5Encode("chinaccnetAdmin"));
}
*/
}