flowable/flowable-engine · error · FlowableIllegalArgumentException

groupId is null

Error message

groupId is null

What it means

CreateGroupCmd's constructor throws FlowableIllegalArgumentException when the groupId is null. This command backs IdentityService.newGroup(...)/createGroup; constructing it without a group id can never succeed, so validation happens at construction time, before any command execution.

Source

Thrown at modules/flowable-idm-engine/src/main/java/org/flowable/idm/engine/impl/cmd/CreateGroupCmd.java:35

import org.flowable.common.engine.api.FlowableIllegalArgumentException;
import org.flowable.common.engine.impl.interceptor.Command;
import org.flowable.common.engine.impl.interceptor.CommandContext;
import org.flowable.idm.api.Group;
import org.flowable.idm.engine.impl.util.CommandContextUtil;

/**
 * @author Tom Baeyens
 */
public class CreateGroupCmd implements Command<Group>, Serializable {

    private static final long serialVersionUID = 1L;

    protected String groupId;

    public CreateGroupCmd(String groupId) {
        if (groupId == null) {
            throw new FlowableIllegalArgumentException("groupId is null");
        }
        this.groupId = groupId;
    }

    @Override
    public Group execute(CommandContext commandContext) {
        return CommandContextUtil.getGroupEntityManager(commandContext).createNewGroup(groupId);
    }

}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Pass a non-null, unique group id string when creating the command.
2. Generate an id before construction (e.g. UUID.randomUUID().toString()) if the source record has none.
3. Validate inputs at the service boundary before invoking IdentityService group-creation APIs.

Example fix

// before
Group g = identityService.newGroup(sourceGroup.getName()); // getName() is null
// after
String groupId = sourceGroup.getName() != null ? sourceGroup.getName() : UUID.randomUUID().toString();
Group g = identityService.newGroup(groupId);

Objects.requireNonNull(groupId, "groupId must not be null"); identityService.newGroup(groupId);

boolean validGroupId(String id) { return id != null && !id.isBlank(); }

try { identityService.newGroup(groupId); } catch (FlowableIllegalArgumentException e) { throw new IllegalArgumentException("Group id required", e); }

When it happens

Trigger: Calling new CreateGroupCmd(null), typically indirectly via an API path that passes a null id into group creation.

Common situations: Programmatic group provisioning where the id is generated or read from an upstream record that has no id yet.

Related errors

• Provided groupId is null
• Provided groupIds is null
• groupId is null
• Privilege name is null
• group is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/8afb5a0dc6bb5370. Report an issue: GitHub.