Java写的MD5加密类

import java.security.MessageDigest;

public class MD5 {
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();
}
/** J
* 转换byte到16进制
* @param b
* @return
*/
private static String byteToHexString(byte b)
{
int n=b;
if (n<0)
{
n=256+n;
}
int d1=n/16;
int d2=n%16;
return hexDigits[d1]+hexDigits[d2];
}
/** J
* 编码
* @param origin
* @return
*/

//MessageDigest 为 JDK 提供的加密类
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("123456"));
}
}