import com.ibm.cloud.sdk.core.security.IamAuthenticator;
...
IamAuthenticator iamAuthenticator = new IamAuthenticator.Builder()
        .apikey("<IBM_CLOUD_API_KEY>")
        .build();

import com.ibm.cloud.secrets_manager_sdk.secrets_manager.v1.SecretsManager;
import com.ibm.cloud.secrets_manager_sdk.secrets_manager.v1.model.*;
import com.ibm.cloud.sdk.core.http.Response;
import com.ibm.cloud.sdk.core.security.IamAuthenticator;

import java.util.Collections;

public class main {

    protected static SecretsManager sm;
    protected static IamAuthenticator iamAuthenticator;

    public static void main(String[] args) { 
        iamAuthenticator = new IamAuthenticator.Builder()
              .apikey("IBM_CLOUD_API_KEY")
              .build();
        sm = new SecretsManager("My Secrets-Manager service", iamAuthenticator);
        sm.setServiceUrl("SERVICE_URL");

        // create arbitrary secret
        CollectionMetadata collectionMetadata = new CollectionMetadata.Builder()
                .collectionType("application/vnd.ibm.secrets-manager.secret+json")
                .collectionTotal(Long.parseLong("1"))
                .build();
      ArbitrarySecretResource arbitrarySecretResource = new ArbitrarySecretResource.Builder()
                .name("example-arbitrary-secret")
                .description("Extended description for this secret.")
                .payload("secret-data")
                .build();
        CreateSecretOptions createSecretOptions = new CreateSecretOptions.Builder()
                .secretType("arbitrary")
                .resources(new java.util.ArrayList<>(Collections.singletonList(arbitrarySecretResource)))
                .metadata(collectionMetadata)
                .build();
        Response<CreateSecret> createResp = sm.createSecret(createSecretOptions).execute();

        String secretId = createResp.getResult().resources().get(0).id();

        // get arbitrary secret
        GetSecretOptions getSecretOptions = new GetSecretOptions.Builder()
                .secretType("arbitrary")
                .id(secretId)
                .build();
        Response<GetSecret> getResp = sm.getSecret(getSecretOptions).execute();

        String secretPayload = (String) getResp.getResult().getResources().get(0).secretData().get("payload");

        System.out.println("The arbitrary secret payload is: " + secretPayload);
    }

}