{"record":{"id":"a179c5941bf09ab9","repo":"flowable/flowable-engine","slug":"must-specify-a-process-instance-id-to-migrate-a179c5","errorCode":null,"errorMessage":"Must specify a process instance id to migrate","messagePattern":"Must specify a process instance id to migrate","errorType":"validation","errorClass":"FlowableException","httpStatus":null,"severity":"error","filePath":"modules/flowable-engine/src/main/java/org/flowable/engine/impl/cmd/ProcessInstanceMigrationValidationCmd.java","lineNumber":35,"sourceCode":"import org.flowable.common.engine.impl.interceptor.Command;\nimport org.flowable.common.engine.impl.interceptor.CommandContext;\nimport org.flowable.engine.impl.util.CommandContextUtil;\nimport org.flowable.engine.migration.ProcessInstanceMigrationDocument;\nimport org.flowable.engine.migration.ProcessInstanceMigrationManager;\nimport org.flowable.engine.migration.ProcessInstanceMigrationValidationResult;\n\npublic class ProcessInstanceMigrationValidationCmd implements Command<ProcessInstanceMigrationValidationResult> {\n    \n    protected String processInstanceId;\n    protected String processDefinitionId;\n    protected String processDefinitionKey;\n    protected int processDefinitionVersion;\n    protected String processDefinitionTenantId;\n    protected ProcessInstanceMigrationDocument processInstanceMigrationDocument;\n\n    public ProcessInstanceMigrationValidationCmd(String processInstanceId, ProcessInstanceMigrationDocument processInstanceMigrationDocument) {\n        if (processInstanceId == null) {\n            throw new FlowableException(\"Must specify a process instance id to migrate\");\n        }\n        \n        if (processInstanceMigrationDocument == null) {\n            throw new FlowableException(\"Must specify a process migration document to migrate\");\n        }\n\n        this.processInstanceId = processInstanceId;\n        this.processInstanceMigrationDocument = processInstanceMigrationDocument;\n    }\n\n    public ProcessInstanceMigrationValidationCmd(ProcessInstanceMigrationDocument processInstanceMigrationDocument, String processDefinitionId) {\n        if (processDefinitionId == null) {\n            throw new FlowableException(\"Must specify a process definition id to migrate\");\n        }\n        \n        if (processInstanceMigrationDocument == null) {\n            throw new FlowableException(\"Must specify a process migration document to migrate\");\n        }","sourceCodeStart":17,"sourceCodeEnd":53,"githubUrl":"https://github.com/flowable/flowable-engine/blob/d6d39ce1c69ff244f2d9dc6af756a9b95e865586/modules/flowable-engine/src/main/java/org/flowable/engine/impl/cmd/ProcessInstanceMigrationValidationCmd.java#L17-L53","documentation":"ProcessInstanceMigrationValidationCmd validates a migration plan against a specific process instance. Its constructor throws when the processInstanceId argument is null, because validation cannot determine which running instance the migration map applies to. This fail-fast check mirrors the migration command's own precondition.","triggerScenarios":"Calling new ProcessInstanceMigrationValidationCmd(null, document) directly, or invoking a validation API path where the process instance id variable is null (e.g. it was never fetched or a lookup returned null).","commonSituations":"Id obtained from a query that returned no row and was not null-checked; hardcoded refactoring where the id placeholder was left null; scripting the internal command classes directly instead of managementService.createProcessInstanceMigrationBuilder().validateMigration(...).","solutions":["Ensure a valid, non-null process instance id is resolved (e.g. from runtimeService.createProcessInstanceQuery()) before validating","Use the public API: managementService.createProcessInstanceMigrationBuilder().migrateToProcessDefinition(...).validateMigration(processInstanceId)","Add a null/empty assertion on the instance id at the call site"],"exampleFix":"// before\nProcessInstance pid = query.singleResult(); // may be null\nnew ProcessInstanceMigrationValidationCmd(pid.getId(), doc); // NPE / throws\n// after\nProcessInstance pid = query.singleResult();\nif (pid != null) {\n    new ProcessInstanceMigrationValidationCmd(pid.getId(), doc);\n}","handlingStrategy":"validation","validationCode":"if (processInstanceId == null || processInstanceId.trim().isEmpty()) {\n    throw new IllegalArgumentException(\"processInstanceId is required for validation\");\n}","typeGuard":"boolean isValidInstanceId(String id) { return id != null && !id.trim().isEmpty(); }","tryCatchPattern":"try {\n    new ProcessInstanceMigrationValidationCmd(instanceId, doc).execute(commandContext);\n} catch (FlowableException e) {\n    if (e.getMessage().contains(\"Must specify a process instance id\")) {\n        // resolve id via runtimeService query and retry once\n    }\n    throw e;\n}","preventionTips":["Resolve the instance id via runtimeService.createProcessInstanceQuery() and null-check the result","Prefer builder.validateMigration(instanceId) over direct command construction","Validate ids at service boundaries before entering migration code"],"tags":["flowable","process-migration","null-argument","validation"],"backgroundTag":"null-argument","analyzedSha":"d6d39ce1c69ff244f2d9dc6af756a9b95e865586","analyzedAt":"2026-09-11T06:41:19.413Z","contentChangedAt":"2026-09-11T06:41:19.413Z","schemaVersion":2},"datasetVersion":"2026-09-18T11:17:12.947Z"}