java实现MD5加密算法的实例代码

package other;

import java.security.messagedigest;
import java.security.nosuchalgorithmexception;
/*
 * md5 算法
*/
public class md5 {

    // 全局数组
    private final static string[] strdigits = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    public md5() {
    }

    // 返回形式为数字跟字符串
    private static string bytetoarraystring(byte bbyte) {
        int iret = bbyte;
        // system.out.println("iret="+iret);
        if (iret < 0) {
            iret += 256;
        }
        int id1 = iret / 16;
        int id2 = iret % 16;
        return strdigits[id1] + strdigits[id2];
    }

    // 返回形式只为数字
    private static string bytetonum(byte bbyte) {
        int iret = bbyte;
        system.out.println("iret1=" + iret);
        if (iret < 0) {
            iret += 256;
        }
        return string.valueof(iret);
    }

    // 转换字节数组为16进制字串
    private static string bytetostring(byte[] bbyte) {
        stringbuffer sbuffer = new stringbuffer();
        for (int i = 0; i < bbyte.length; i++) {
            sbuffer.append(bytetoarraystring(bbyte[i]));
        }
        return sbuffer.tostring();
    }

    public static string getmd5code(string strobj) {
        string resultstring = null;
        try {
            resultstring = new string(strobj);
            messagedigest md = messagedigest.getinstance("md5");
            // md.digest() 该函数返回值为存放哈希值结果的byte数组
            resultstring = bytetostring(md.digest(strobj.getbytes()));
        } catch (nosuchalgorithmexception ex) {
            ex.printstacktrace();
        }
        return resultstring;
    }

    public static void main(string[] args) {
        md5 getmd5 = new md5();
        system.out.println(getmd5.getmd5code("000000"));
    }
}