SHA256加密示例代码(JAVA)

import org.apache.commons.lang.StringUtils;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA256Utils {
    /**
     * 利用java原生的类实现SHA256加密
     *
     * @param str 加密后的报文
     * @return
     */
    public static String getSHA256(String str) {
        if (StringUtils.isNotEmpty(str) && str.length() == 64) {
            return 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;
    }
    /**
     * 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) {
                // 1得到一位的进行补0操作
                stringBuffer.append("0");
            }
            stringBuffer.append(temp);
        }
        return stringBuffer.toString();
    }
}