使用keycloak-admin-client lib

maven

	<dependency>
			<groupId>org.keycloak</groupId>
			<artifactId>keycloak-admin-client</artifactId>
			<version>12.0.4</version>
	</dependency>

    Keycloak keycloak = Keycloak.getInstance(keycloakserverurl, "master", "admin", "PASSWORD", "demoapp");
        RealmRepresentation realm = keycloak.realm("master").toRepresentation() ;
//          create a user
        UserRepresentation userRepresentation = new UserRepresentation();
        userRepresentation.setUsername("ccc");
        userRepresentation.setFirstName("first name");
        userRepresentation.setEmail("ddd@ccc");
//        userRepresentation.setRequiredActions(Collections.emptyList());
        userRepresentation.setEnabled(true);

        CredentialRepresentation credentialRepresentation = new CredentialRepresentation();
        credentialRepresentation.setType(CredentialRepresentation.PASSWORD);
        credentialRepresentation.setValue("1234");

        userRepresentation.setCredentials(Collections.singletonList(credentialRepresentation));

        Response response = keycloak.realm("master").users().create(userRepresentation);
        System.out.println("response status: " + response.getStatus());

參考

https://www.keycloak.org/docs/latest/server_development/