字符串生成64位hash字符串

使用sha-256生成32位byte數組，基本很難重復，再轉化為64位16進制數字字符串。

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA256Util {
	public static void main(String[] args) {
		System.out.println(getSHA256StrJava("130"));
		System.out.println(getSHA256StrJava("13034234324weweasxwsqszASxsadreqq	scdzsd"));
		System.out.println(getSHA256StrJava("13034234324weweasxwsqszASxsadreq{ww=bb,see=2ss}"));

	}

	public static String getSHA256StrJava(String str) {

		MessageDigest messageDigest;
		String encodeStr = "";
		try {
			messageDigest = MessageDigest.getInstance("SHA-256");
			messageDigest.update(str.getBytes("UTF-8"));
			encodeStr = byte2Hex(messageDigest.digest());
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return encodeStr;
	}

	private static String byte2Hex(byte[] bytes) {
		System.out.println(bytes.length);
		StringBuffer stringBuffer = new StringBuffer();
		String temp = null;
		for (int i = 0; i < bytes.length; i++) {
			temp = Integer.toHexString(bytes[i] & 0xFF);
			if (temp.length() == 1) {
				// 1得到一位的進行補0操作
				stringBuffer.append("0");
			}
			stringBuffer.append(temp);
		}
		return stringBuffer.toString();
	}

}