This topic is intended to help users quickly build a Ganos development environment for test purposes by coding. After you read this topic, you will learn how to manage Ganos spatio-temporal data, including how to connect to a database, create an index, import data, and query data.
Dependencies:
<dependencies>
<dependency>
<groupId>org.locationtech.geomesa</groupId>
<artifactId>geomesa-hbase-datastore_2.11</artifactId>
<version>${geomesa.version}</version>
<exclusions>
<exclusion>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-server</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-common</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-protocol</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.aliyun.hbase</groupId>
<artifactId>alihbase-client</artifactId>
<version>${hbase.version}</version>
<exclusions>
<exclusion>
<artifactId>com.google.guava</artifactId>
<groupId>guava</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.aliyun.hbase</groupId>
<artifactId>alihbase-server</artifactId>
<version>${hbase.version}</version>
</dependency>
<dependency>
<groupId>com.aliyun.hbase</groupId>
<artifactId>alihbase-common</artifactId>
<version>${hbase.version}</version>
</dependency>
<dependency>
<groupId>com.aliyun.hbase</groupId>
<artifactId>alihbase-protocol</artifactId>
<version>${hbase.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.83</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<inherited>true</inherited>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
Sample code and descriptions
package com.aliyun.tst;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;
import org.geotools.data.DataStore;
import org.geotools.data.DataStoreFinder;
import org.geotools.data.Query;
import org.geotools.data.Transaction;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.simple.SimpleFeatureWriter;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.factory.Hints;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.filter.text.ecql.ECQL;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.locationtech.geomesa.utils.geotools.SimpleFeatureTypes;
import org.opengis.feature.Feature;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.filter.FilterFactory2;
import org.opengis.filter.sort.SortBy;
import org.opengis.filter.sort.SortOrder;
import java.io.BufferedReader;
import java.io.FileReader;
import java.text.SimpleDateFormat;
import java.util.*;
public class Demo {
public static final String ZK = "localhost"; //The ZooKeeper endpoint.
public static void main(String args[]){
try{
DataStore ds=null;
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd' 'HH:mm:ss");
//Configure connection parameters.
Map<String, String> params= new HashMap<>();
params.put("hbase.zookeepers",ZK);
params.put("hbase.catalog","test_catalog");
//Initialize the DataStore.
ds= DataStoreFinder.getDataStore(params);
//Use SimpleFeatureType to define the table schema.
String sft_name="point";
SimpleFeatureType sft=
SimpleFeatureTypes.createType(sft_name, "name:String,dtg:Date,*geom:Point:srid=4326");
//Specify Gzip as the compression algorithm.
sft.getUserData().put("geomesa.table.compression.enabled", "true");
sft.getUserData().put("geomesa.table.compression.type", "gz");
//Create a table.
ds.createSchema(sft);
/*
* Create a GeometryFactory object.
*/
GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
SimpleFeatureBuilder builder = new SimpleFeatureBuilder(sft);
//Construct spatial data (points).
Point point1 = geometryFactory.createPoint(new Coordinate(120.301,35.086));
Point point2 = geometryFactory.createPoint(new Coordinate(120.301,35.076));
Point point3 = geometryFactory.createPoint(new Coordinate(120.301,35.066));
//Construct SimpleFeatures of points.
List<SimpleFeature> features=new ArrayList<>();
features.add(builder.buildFeature("1", new Object[]{"point1",new Date(),point1}));
features.add(builder.buildFeature("2", new Object[]{"point2",new Date(),point2}));
features.add(builder.buildFeature("3", new Object[]{"point3",new Date(),point3}));
//Import SimpleFeature content.
SimpleFeatureWriter writer=(SimpleFeatureWriter)ds.getFeatureWriterAppend(sft_name, Transaction.AUTO_COMMIT);
for(SimpleFeature feature:features){
SimpleFeature toWrite=writer.next();
toWrite.setAttributes(feature.getAttributes());
toWrite.getUserData().putAll(feature.getUserData());
writer.write();
}
writer.close();
//Construct spatio-temporal query conditions.
long t1=format.parse("2019-01-19 11:45:00").getTime();
long t2=format.parse("2019-02-21 12:15:00").getTime();
String sortField="dtg";//Specify the sorting field. In this example, the data is sorted by date.
FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
SortBy[] sort = new SortBy[]{ff.sort(sortField, SortOrder.DESCENDING)};
//Construct a query object.
Query query = new Query(sft_name, ECQL.toFilter( "bbox(geom,120,20,130,40) AND dtg >= "+t1+" AND dtg <= "+t2));
query.setSortBy(sort);
SimpleFeatureCollection result=ds.getFeatureSource(sft_name).getFeatures(query);
SimpleFeatureIterator iterator=result.features();
//Print the query result.
long sum = 0;
while (iterator.hasNext()) {
System.out.println(iterator.next());
sum++;
}
System.out.println("Total number of queries:" + sum);
}
catch (Exception e){
e.printStackTrace();
}
}
}
After you successfully run the preceding script, the three "Point" SimpleFeatures
are printed. The query result is as follows: 