geomesa如何实现sql查询而不是用ecql

Geomesa提供了一种称为GeoTools的工具，可以在Java中使用它来查询数据。GeoTools提供了SQL解析器，可以将SQL查询语句转换为ECQL查询语句。因此，您可以使用GeoTools API中的SQL查询解析器来实现SQL查询而不是使用ECQL。以下是一个示例：

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.Query;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.text.cql2.CQLException;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory2;

public class SqlQueryExample {

  public static void main(String[] args) throws IOException, CQLException {
    // Connect to the data store
    Map<String, Object> connectionParams = new HashMap<>();
    connectionParams.put("url", "accumulo://localhost:2181/geomesa");
    connectionParams.put("user", "myuser");
    connectionParams.put("password", "mypassword");
    connectionParams.put("tableName", "mytable");
    connectionParams.put("useMock", "false");
    DataStore dataStore = DataStoreFinder.getDataStore(connectionParams);

    // Get the feature source and type
    SimpleFeatureSource featureSource = dataStore.getFeatureSource("mytable");
    SimpleFeatureType featureType = featureSource.getSchema();

    // Parse the SQL query
    FilterFactory2 filterFactory = CommonFactoryFinder.getFilterFactory2();
    String sql = "SELECT * FROM mytable WHERE name = 'John'";
    Query query = new Query();
    query.setFilter(filterFactory.literal(true));
    query.setMaxFeatures(Integer.MAX_VALUE);
    query.setStartIndex(0);
    query.setTypeName(featureType.getTypeName());
    query.setHandle("sql");
    query.setPropertyNames(Query.ALL_NAMES);
    query.setSortBy(new String[] { "timestamp" });
    query.setHints(new HashMap<>());
    query.getHints().put(QueryHints.QUERY_INDEX_FORCE_CHOICE, Boolean.TRUE);
    query.getHints().put(QueryHints.QUERY_INDEX, "myindex");
    query.getHints().put(QueryHints.QUERY_INDEX_LOGGING, Boolean.TRUE);
    query.getHints().put(QueryHints.QUERY_PLAN_EXPLAIN, Boolean.TRUE);
    query.getHints().put(QueryHints.QUERY_TIMEOUT, 60000L);
    Filter filter = filterFactory.sql(sql, featureType);
    query.setFilter(filter);

    // Execute the query and print the results
    SimpleFeatureCollection features = featureSource.getFeatures(query);
    try (SimpleFeatureIterator iterator = features.features()) {
      while (iterator.hasNext()) {
        SimpleFeature feature = iterator.next();
        System.out.println(feature.getID() + ": " + feature.getAttribute("name"));
      }
    }

    // Close the data store
    dataStore.dispose();
  }
}

在此示例中，我们使用了filterFactory.sql()方法将SQL查询语句转换为Filter对象，然后将其设置为查询的过滤器。请注意，我们还设置了一些查询提示，例如强制使用索引，选择索引和查询超时。这些提示是可选的，但可以帮助优化查询性能。