一个登录密码MD5加密的封装类代码共享

*
* @(#)Encrypter.java 
*      
*
* 
*
* All rights reserved.
*
*  *
*
* 功能描述：
* 公用方法描述：
*
* 修改人：
* 修改日期：
* 修改原因：
*
*/



import java.security.MessageDigest;
import java.security.Security;
import java.security.NoSuchAlgorithmException;
import java.security.Provider;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/** *//**
* <p>
* 加密类，里面封装的是MD5的处理机制 <br>
*
* @author
* @since  */
public class Encrypter
...{

    private static String DEFAULT_JCE = "com.sun.crypto.provider.SunJCE";
    private static String IBM_JCE = "com.ibm.crypto.provider.IBMJCE";
    protected static final Log log = LogFactory.getLog(Encrypter.class);
    /** *//**
     * 初始化系统加密算法提供者
     */
    static
    ...{
       
        try
        ...{
            Security.addProvider((Provider)Class.forName(DEFAULT_JCE).newInstance());
        }
        catch (Exception e)
        ...{
            log.info(e);
            try
            ...{
                Security.addProvider((Provider)Class.forName(IBM_JCE).newInstance());
            }
            catch (Exception ex)
            ...{
                log.info(ex);
            }
        }
    }

    /** *//**
     * get hex string
     *
     * @param x
     * @return
     */
    private static String hexDigit(byte x)
    ...{
        StringBuffer sb = new StringBuffer();
        char c;
        // First nibble
        c = (char) ((x >> 4) & 0xf);
        if (c > 9)
        ...{
            c = (char) ((c - 10) + 'a');
        }
        else
        ...{
            c = (char) (c + '0');
        }
        sb.append(c);
        // Second nibble
        c = (char) (x & 0xf);
        if (c > 9)
        ...{
            c = (char) ((c - 10) + 'a');
        }
        else
        ...{
            c = (char) (c + '0');
        }
        sb.append(c);
        return sb.toString();
    }

    /** *//**
     * 加密
     *
     * @param content
     *            加密内容
     * @return 加密串
     */
    public static String encrypt(String content)
    ...{
        try
        ...{
            MessageDigest algorithm = null;
            algorithm = MessageDigest.getInstance("MD5");
            algorithm.reset();
            if (content != null)
            ...{
                algorithm.reset();
                algorithm.update(content.getBytes());
                byte digest[] = algorithm.digest();
                StringBuffer hexString = new StringBuffer();
                int digestLength = digest.length;
                for (int i = 0; i < digestLength; i++)
                ...{
                    hexString.append(hexDigit(digest[i]));
                    hexString.append(" ");
                }
                return hexString.toString();
            }
            else
            ...{
                return "";
            }
        }
        catch (NoSuchAlgorithmException ex)
        ...{
            //加密过程中出现异常，采用原始的的内容串
            return content;
        }
    }
   
    public static void main(String[] args)...{
        System.out.println("//" +  Encrypter.encrypt("123") + "//");
    }
}



登录Action



//获取用户名,密码
            String userName = request.getParameter("username");
            String passWord = Encrypter.encrypt(request
                    .getParameter("password"));