CSV Plugin¶

The gt-csv module is a plugin which provides a CSVDataStore. It is pluggable into GeoServer’s importer, allowing read/write capabilities for .csv files. The plugin supports three strategies: AttributesOnly, LatLon, and SpecifiedWKT. Essentially, each strategy will read and store data in a slightly different way.

Maven:

<dependency>
   <groupId>org.geotools</groupId>
   <artifactId>gt-csv</artifactId>
   <version>${geotools.version}</version>
 </dependency>

Connection Parameters¶

The following connection parameters are available:

Parameter	Description
`url`	A URL of the file ending in `csv`
`strategy`	The strategy to use in processing the input file `guess` - try to figure out best strategy `AttributesOnly` - read in all fields as is `specify` - use the specified lat/lon columns `wkt` - use a field containing WKT
`latField`	The field containing the latitude value in `specify` strategy.
`lngField`	The field containing the longitude value in `specify` strategy.
`wktField`	The field containing the WKT value in `WKT` strategy.
`writeprj`	write out a `.prj` file with the CRS (Optional)
`quoteAll`	Should all fields be quoted when writing, default is false (Optional).
`quoteChar`	Character to use to quote field, default is `"` (Optional).
`separator`	Character to use to separate fields, default is `,` (Optional).
`lineSeperator`	String used to separate lines, default is the system line ending (Optional).
`escapeChar`	Character used to escape quotes in fields, default `\\` (Optional).
`namespace`	URI to the namespace (Optional).

Strategies¶

LatLon Strategy¶

This strategy uses the two field names set in latField and lngField and converts the values in these fields into a Point object in the feature called location.

Guess Strategy¶

This strategy looks through the field names and picks one that is equal to longitude, lon, long or lng to use for longitude. For latitude it looks for fields called latitude or lat. It then converts the values in these fields into a Point object in the feature called location.

WKT Strategy¶

This strategy parses the value in the field specified in wktField into a WGS84 geometry object in the features with the same name as the field.

AttributesOnly Strategy¶

This strategy reads all the fields in the file in unmodified.

Access¶

Reading in an existing file:

Map<String, Serializable> params = new HashMap<String, Serializable>();
params.put("file", "locations.csv");
params.put(CSVDataStoreFactory.STRATEGYP.key, CSVDataStoreFactory.SPECIFC_STRATEGY);
params.put(CSVDataStoreFactory.LATFIELDP.key, "LAT");
params.put(CSVDataStoreFactory.LnGFIELDP.key, "LON");
DataStore store = DataStoreFinder.getDataStore(params);

String typeName = dataStore.getTypeNames()[0];

FeatureSource<SimpleFeatureType, SimpleFeature> source =
        dataStore.getFeatureSource(typeName);
Filter filter = Filter.INCLUDE; // ECQL.toFilter("BBOX(THE_GEOM, 10,20,30,40)")

FeatureCollection<SimpleFeatureType, SimpleFeature> collection = source.getFeatures(filter);
try (FeatureIterator<SimpleFeature> features = collection.features()) {
    while (features.hasNext()) {
        SimpleFeature feature = features.next();
        System.out.print(feature.getID());
        System.out.print(": ");
        System.out.println(feature.getDefaultGeometryProperty().getValue());
    }
}

Writing¶

To write to a CSV file:

File file2 = File.createTempFile("CSVTest", ".csv");
Map<String, Serializable> params2 = new HashMap<String, Serializable>();
params2.put("file", file2);
params2.put(CSVDataStoreFactory.STRATEGYP.key, CSVDataStoreFactory.WKT_STRATEGY);
params2.put(CSVDataStoreFactory.WKTP.key, "the_geom_wkt");

CSVDataStoreFactory factory = new CSVDataStoreFactory();
DataStore datastore = factory.createNewDataStore(params2);
SimpleFeatureType featureType = store.getSchema();

datastore.createSchema(featureType);
SimpleFeatureSource source = datastore.getFeatureSource();
if (source instanceof SimpleFeatureStore) {
    SimpleFeatureStore outStore = (SimpleFeatureStore) source;
    outStore.addFeatures(store.getFeatureSource().getFeatures());
} else {
    fail("Can't write to new CSVDatastore");
}

GeoTools

OSGeo