jsp中如何对数据进行加密

/**
* 类名： MD5Digest

* 说明： 用来进行密码加密的md5公用参数

* 编写日期： 2001/03/05

* 修改者：

* 修改信息：

* @author edgarlo edgarlo@china.com
* @version 1.0

*/

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

public class MD5Digest
{

private MessageDigest __md5 = null;
private StringBuffer __digestBuffer = null;

public MD5Digest()
throws NoSuchAlgorithmException
{
__md5 = MessageDigest.getInstance("MD5");
__digestBuffer = new StringBuffer();
}

public String md5crypt(String s)
{
__digestBuffer.setLength(0);
byte abyte0[] = __md5.digest(s.getBytes());
for(int i = 0; i < abyte0.length; i++)
__digestBuffer.append(toHex(abyte0[i]));

return __digestBuffer.toString();
}
public String toHex(byte one){
String HEX="0123456789ABCDEF";
char[] result=new char[2];
result[0]=HEX.charAt((one & 0xf0) >> 4);
result[1]=HEX.charAt(one & 0x0f);
String mm=new String(result);
return mm;
}
}