/**
* encode By SHA-256
* @param str
* @return
*/
public static String encodeBySHA256(String str) {
if (str == null) {
return null;}
try {
MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
messageDigest.reset();
messageDigest.update(str.getBytes());
return getFormattedText(messageDigest.digest());
} catch (Exception e) {
throw new RuntimeException(e);}
}
private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5','6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
/**
* Takes the raw bytes from the digest and formats them correct.
* @param bytes the raw bytes from the digest.
* @return the formatted bytes.
*/
private static String getFormattedText(byte[] bytes) {
int len = bytes.length;
StringBuilder buf = new StringBuilder(len * 2);
// 把密文转换成十六进制的字符串形式
for (int j = 0; j < len; j++) {
buf.append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);
buf.append(HEX_DIGITS[bytes[j] & 0x0f]);
}
return buf.toString();
}