SHA-256工具类（非对称加密）

package com.dituhui.egispweb.radar.filter;

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

public class SHA256Util {

    public static String getSHA256String(String str){
        MessageDigest messageDigest;
        String sha256Str = "";
        try {
            messageDigest = MessageDigest.getInstance("SHA-256");
            messageDigest.update(str.getBytes("UTF-8"));
            sha256Str=byte2Hex(messageDigest.digest());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return sha256Str;
    }

    /**
     * 将byte转为16进制
     * @param bytes
     * @return
     */
    private static String byte2Hex(byte[]bytes){
        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){
                stringBuffer.append("0");
            }
            stringBuffer.append(temp);
        }

        return stringBuffer.toString();

    }




}