import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.util.HashMap;
import java.util.Map;

public class SHA {
	public static final String KEY_SHA = "SHA";   
	public static final String ra="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

	/**
	 * 字串sha加密
	 * @param s 要加密的字串
	 * @return 加密後的字串
	 */
	public static String sha(String s)
	{
	    BigInteger sha =null;
	    byte[] bys = s.getBytes();   
	    try {
	         MessageDigest messageDigest = MessageDigest.getInstance(KEY_SHA);  
	         messageDigest.update(bys);
	         sha = new BigInteger(messageDigest.digest());
	    } catch (Exception e) {
	    	e.printStackTrace();
	    }
	    return sha.toString(32);
	}
	
	/**
	 * 字串+隨機鹽 sha加密
	 * @param s 要加密的字串
	 * @return 鹽和加密後的字串
	 */	
	public static Map<String,String> getResult(String s){
		Map<String,String> map=new HashMap<String,String>();
		String salt=getSalt();
		map.put("salt", salt);//鹽
		map.put("password", sha(s+salt));//加密後的密碼
 	    return map;
	}
	
	/**
	 * 生成隨機鹽
	 * @return 隨機生成的鹽
	 */
	private static String getSalt() {
		SecureRandom random=new SecureRandom();
		int length=random.nextInt(5)+8;//鹽的長度，這裡是8-12可自行調整
        char[] text = new char[length];
        for (int i = 0; i < length; i++) {
            text[i] = ra.charAt(random.nextInt(ra.length()));
        }
        return new String(text);
    }
	
	/**
	 * 測試方法
	 * @param args
	 */
	public static void main(String[] args) {
		System.out.println(getResult("12345678"));
	}