download：Spring Cloud Alibaba 大型互联网领域多场景最佳实践
private static final char[] HEX_CHAR = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
/** 获取签名的MD5摘要 */
public String[] signatureDigest() {
pkgInfo = mContext.getPackageManager().getPackageInfo(
mContext.getPackageName(), PackageManager.GET_SIGNATURES);
int length = pkgInfo.signatures.length;
String[] digests = new String[length];
for (int i = 0; i < length; ++i) {
Signature sign = mPkgInfo.signatures[i];
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
byte[] digest = md5.digest(sign.toByteArray()); // get digest with md5 algorithm
digests[i] = toHexString(digest);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
digests[i] = null;
}
}
return digests;
}
/** 将字节数组转化为对应的十六进制字符串 */
private String toHexString(byte[] rawByteArray) {
char[] chars = new char[rawByteArray.length * 2];
for (int i = 0; i < rawByteArray.length; ++i) {
byte b = rawByteArray[i];
chars[i*2] = HEX_CHAR[(b >>> 4 & 0x0F)];
chars[i*2+1] = HEX_CHAR[(b & 0x0F)];
}
return new String(chars);
}