17.9. 事务性写入

卡夫卡支持 transactional writes 。GeoMesa通过GeoTool公开此功能 transaction API ：

import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.DefaultTransaction;
import org.geotools.data.FeatureWriter;
import org.geotools.data.Transaction;

DataStore store = DataStoreFinder.getDataStore(params);
// the transaction will contain the Kafka producer, so make sure to close it when finished
try (Transaction transaction = new DefaultTransaction()) {
    // pass the transaction when getting a feature writer
    try (FeatureWriter<SimpleFeatureType, SimpleFeature> writer =
                store.getFeatureWriterAppend("my-type", transaction)) {
         // write some features (elided), then commit the transaction:
        transaction.commit();
        // if you get an error (elided), then rollback the transaction:
        transaction.rollback();
    }
    // re-using the transaction will re-use the Kafka producer
    try (FeatureWriter<SimpleFeatureType, SimpleFeature> writer =
               store.getFeatureWriterAppend("my-type", transaction)) {
        // write some features (elided), then commit the transaction:
        transaction.commit();
    }
}