4.2.4.6.1. Pessimistic Lock of Nablarch Batch Application¶

This section shows an implementation example to perform pessimistic lock in the Nablarch batch application. By implementing with reference to the examples shown below, the lock duration can be reduced and the effect on other processes can be reduced.

Points

The data reader fetches only the primary key of the record to be processed.
Perform pessimistic lock with handle method. For information on pessimistic lock using Universal DAO, see Pessimistic locking.

public class SampleAction extends BatchAction<SqlRow> {

    @Override
    public DataReader<SqlRow> createReader(final ExecutionContext ctx) {
        final DatabaseRecordReader reader = new DatabaseRecordReader();
        final SqlPStatement statement = DbConnectionContext.getConnection()
                .prepareParameterizedSqlStatementBySqlId(
                        Project.class.getName() + "#GET_ID");

        // Omit search condition acquisition process

        reader.setStatement(statement, condition);
        return reader;
    }

    @Override
    public Result handle(final SqlRow inputData, final ExecutionContext ctx) {
        final Project project =
                UniversalDao.findBySqlFile(Project.class, "FIND_BY_ID_WITH_LOCK", inputData);

        // Omitted for business process

        UniversalDao.update(project);
        return new Success();
    }
}