Quickstart¶
Here we’ll briefly tour basic features of ADBC with Java JNI driver manager and the PostgreSQL driver.
Installation¶
To include ADBC in your Maven project, add the following dependency:
<dependency>
<groupId>org.apache.arrow.adbc</groupId>
<artifactId>adbc-driver-jni</artifactId>
<version>${adbc.version}</version>
</dependency>
Installing Drivers¶
See Installing Drivers for instructions on installing ADBC drivers for the database you want to connect to. For the example below, you could install dbc and then install the PostgreSQL driver with:
dbc install postgresql
Imports¶
For the examples in this section, the following imports are required:
import java.util.HashMap;
import java.util.Map;
import org.apache.arrow.adbc.core.AdbcConnection;
import org.apache.arrow.adbc.core.AdbcDatabase;
import org.apache.arrow.adbc.core.AdbcDriver;
import org.apache.arrow.adbc.core.AdbcException;
import org.apache.arrow.adbc.core.AdbcStatement;
import org.apache.arrow.adbc.driver.jni.JniDriver;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.memory.RootAllocator;
Basic Usage¶
Map<String, Object> parameters = new HashMap<>();
JniDriver.PARAM_DRIVER.set(parameters, "postgresql");
AdbcDriver.PARAM_URI.set(parameters, "postgresql://localhost:5432/postgres");
try (
BufferAllocator allocator = new RootAllocator();
AdbcDatabase db = new JniDriver(allocator).open(parameters);
AdbcConnection adbcConnection = db.connect();
AdbcStatement stmt = adbcConnection.createStatement();
) {
stmt.setSqlQuery("select * from foo");
try (AdbcStatement.QueryResult queryResult = stmt.executeQuery()) {
while (queryResult.getReader().loadNextBatch()) {
// process batch
}
}
} catch (AdbcException e) {
// throw
}
In application code, the connection must be closed after usage or memory may leak. It is recommended to wrap the connection in a try-with-resources block for automatic resource management. In this example, we are connecting to a PostgreSQL database, specifically the default database “postgres”.
Note that creating a statement is also wrapped in the try-with-resources block. Assuming we have a table “foo” in the database, an example for setting and executing the query is also provided.
Next Steps¶
Check out the Java API documentation for more details
See the drivers to see which databases are supported
Explore more examples in the adbc-quickstarts repository
Explore the Java source code for additional examples