get md5

gistfile1.java

import java.security.*;
import java.util.*;

public class MD5
{

    int limit_position_number;

    public MD5()
    {
	limit_position_number = 30;
    }

    public int getLimitPositionNumber()
    {
	return this.limit_position_number;

    }

    public void setLimitPositionNumber(int limit_postion_num)
    {
	this.limit_position_number = limit_postion_num; 
    }

    public String encryptData(String str)
    { 
	StringBuilder sb = new StringBuilder();

	try
	{ 
	    MessageDigest md5 = MessageDigest.getInstance("MD5");
	    md5.update(str.getBytes());
	    byte[] md5encrypt = md5.digest();

	    for (int i = 0; i < md5encrypt.length; i++)
	    {
		sb.append(Integer.toHexString((int) md5encrypt[i] & 0xFF));
	    } 
	}
	catch (Exception e)
	{
	    e.printStackTrace();
	}

	return assemlyMD5(sb);
    }

    public String assemlyMD5(StringBuilder ori_md5)
    {
	for (;;)
	{
	    int current_md5_len = ori_md5.toString().length();
	    if (current_md5_len > this.limit_position_number)
	    {
		int last_index = current_md5_len - 1;
		ori_md5.deleteCharAt(last_index);
	    }
	    else if (current_md5_len < this.limit_position_number)
	    {
		Random random = new Random();

		int gen_rand_vaule = random.nextInt(10);
		ori_md5.append(gen_rand_vaule);
	    }
	    else
	    {
		break;
	    }

	}

	return ori_md5.toString();
    }
}