导入：

import org.apache.commons.codec.digest.DigestUtils;

　　代码：

public static String md5(String src) {
        return DigestUtils.md5Hex(src);
    }
    
    private static final String salt = "1a2b3c4d";
    
    public static String inputPassToFormPass(String inputPass) {
        String str = ""+salt.charAt(0)+salt.charAt(2) + inputPass +salt.charAt(5) + salt.charAt(4);
        System.out.println(str);
        return md5(str);
    }
    
    public static String formPassToDBPass(String formPass, String salt) {
        String str = ""+salt.charAt(0)+salt.charAt(2) + formPass +salt.charAt(5) + salt.charAt(4);
        return md5(str);
    }
    
    public static String inputPassToDbPass(String inputPass, String saltDB) {
        String formPass = inputPassToFormPass(inputPass);
        String dbPass = formPassToDBPass(formPass, saltDB);
        return dbPass;
    }

　　md5：帮助类

import java.io.File;
import java.io.FileInputStream;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;

/**
 * MD5加密工具类
 */
public class MD5Util {
    private static final char DIGITS[] = { '0', '1', '2', '3', '4', '5', '6',
        '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

    /**
     * 获取文件的MD5码
     * 
     * @param absPath
     *            文件路径
     * @return 文件的MD5码
     */
    public final static String getFileMD5(String absPath) {
    try {
        File file = new File(absPath);
        MessageDigest mdTemp = MessageDigest.getInstance("MD5");
        FileInputStream fis = new FileInputStream(file);
        FileChannel filechannel = fis.getChannel();
        MappedByteBuffer mbb = filechannel
            .map(FileChannel.MapMode.READ_ONLY, 0, file.length());
        mdTemp.update(mbb);
        byte[] md = mdTemp.digest();
        int j = md.length;
        char str[] = new char[j * 2];
        int k = 0;
        for (int i = 0; i < j; i++) {
        byte byte0 = md[i];
        str[k++] = DIGITS[byte0 >>> 4 & 0xf];
        str[k++] = DIGITS[byte0 & 0xf];
        }
        fis.close();
        return new String(str);
    } catch (Exception e) {
        return "";
    }
    }

    /**
     * 获取指定字符串的MD5码
     * 
     * @param s
     *            字符串
     * @return 字符串的MD5码
     */
    public final static String getMD5(String s) {
    char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
        'a', 'b', 'c', 'd', 'e', 'f' };
    try {
        byte[] strTemp = s.getBytes();
        MessageDigest mdTemp = MessageDigest.getInstance("MD5");
        mdTemp.update(strTemp);
        byte[] md = mdTemp.digest();
        int j = md.length;
        char str[] = new char[j * 2];
        int k = 0;
        for (int i = 0; i < j; i++) {
        byte byte0 = md[i];
        str[k++] = hexDigits[byte0 >>> 4 & 0xf];
        str[k++] = hexDigits[byte0 & 0xf];
        }
        return new String(str);
    } catch (Exception e) {
        return null;
    }
    }
    
    public static void main(String[] args) {
    System.out.println(getMD5("admin"));
    }
}