keystoreファイルから

keystoreファイルがある場所へ移動し、下記を打ち込む。
keytool -list -keystore [file name]

$ keytool -list -keystore my-upload-key.keystore
Enter keystore password:
Keystore type: jks
Keystore provider: SUN

Your keystore contains 1 entry

my-key-alias, Aug 28, 2019, PrivateKeyEntry,
Certificate fingerprint (SHA1): F5:A5:7E:6F:C2:CE:08

Warning:
The JKS keystore uses a proprietary format. It is recommended to migrate to PKCS12 which is an industry standard format using "keytool -importkeystore -srckeystore my-upload-key.keystore -destkeystore my-upload-key.keystore -deststoretype pkcs12".

apkファイルから

apkファイルがある場所へ移動し、下記を打ち込む。
keytool -list -printcert -jarfile [file name]

$ keytool -list -printcert -jarfile app-release.apk
Signer #1:

Signature:

Owner: CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
Issuer: CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
Serial number: 2085
Valid from: Mon Sep 02 19:52:00 PST 2019 until: Fri Jan 18 19:52:00 PST 2047
Certificate fingerprints:
	 MD5:  26:D0:0D:AA:71:7C:E4:30:D1
	 SHA1: 93:A2:2C:38:3B:AF:A9:2F:82
	 SHA256: F3:A4:38:06:2C:A5:6C:8A:54:4F:36:E6:23:A0:8E:38:50:DF
Signature algorithm name: SHA256