1-SecurityRealm.java

public interface SecurityRealm {
    RealmIdentity createRealmIdentity(String name) throws RealmUnavailableException;
    CredentialSupport getCredentialSupport(Class<?> credentialType, String algorithmName) throws RealmUnavailableException;
}

2-RealmIdentity.java

public interface RealmIdentity {
    String getName();
    CredentialSupport getCredentialSupport(Class<?> credentialType, String algorithmName) throws RealmUnavailableException;
    <C> C getCredential(Class<C> credentialType, final String algorithmName) throws RealmUnavailableException;
    boolean verifyCredential(Object credential) throws RealmUnavailableException;
    boolean exists() throws RealmUnavailableException;
    default void dispose() {}
    AuthorizationIdentity getAuthorizationIdentity() throws RealmUnavailableException;
}