MD5加密算法示例

工具類代碼示例：

package com.mischen.it.util;

import java.security.MessageDigest;

/**
 * 
 */
public class MD5Util {

    /**
     * 私有構造方法,將該工具類設爲單例模式.
     */
    private MD5Util() {
    }

    private static final String[] hex = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    public static String encode(String password) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            byte[] byteArray = md5.digest(password.getBytes("utf-8"));
            String passwordMD5 = byteArrayToHexString(byteArray);
            return passwordMD5;
        } catch (Exception e) {
            e.fillInStackTrace();
        }
        return password;
    }

    private static String byteArrayToHexString(byte[] byteArray) {
        StringBuffer sb = new StringBuffer();
        for (byte b : byteArray) {
            sb.append(byteToHexChar(b));
        }
        return sb.toString();
    }

    private static Object byteToHexChar(byte b) {
        int n = b;
        if (n < 0) {
            n = 256 + n;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hex[d1] + hex[d2];
    }
}

 

調用代碼：

 /**
     * 獲取參數簽名
     * @param paramMap  簽名參數
     * @param paySecret 簽名密鑰
     * @return
     */
    public static String  getSign (Map<String , Object> paramMap , String paySecret){
        SortedMap<String, Object> smap = new TreeMap<String, Object>(paramMap);
        StringBuffer stringBuffer = new StringBuffer();
        for (Map.Entry<String, Object> m : smap.entrySet()) {
            Object value = m.getValue();
            if (value != null && StringUtils.isNotBlank(String.valueOf(value))){
                stringBuffer.append(m.getKey()).append("=").append(m.getValue()).append("&");
            }
        }
        stringBuffer.delete(stringBuffer.length() - 1, stringBuffer.length());

        String argPreSign = stringBuffer.append("&paySecret=").append(paySecret).toString();
        String signStr = MD5Util.encode(argPreSign).toUpperCase();

        return signStr;
    }