jdbc

AGE AGType parser and driver support for Java

AGType parser and driver support for Apache AGE, graph extension for PostgreSQL.

Prerequisites

You should have installed following jar files and packages.

• gradle build tool
• postgres JDBC driver
• antlr4-4.9.2-complete
• common-lang3
• commons-text-1.6

Kindly unzip the jars if they are zipped before using them.

Build from source

git clone https://github.com/apache/age.git
cd age/drivers/jdbc

gradle assemble

After the build completes successfully, a jar file will be created at path age/drivers/jdbc/lib/build/libs/lib.jar. Now add this JAR file to class path for your java project.

Getting Started

• Install AGE on your machine. https://age.apache.org/age-manual/master/index.html
• Add the downloaded jar files to class path.
• Connect to the postgres server using pg JDBC drivers.

Lets say we have a graph named demo_graph having some nodes. In order to extract its nodes we can try following steps. To create some more graphs. https://github.com/apache/age#quick-start. Following sample code shows how to return query result as Agtype.

import org.apache.age.jdbc.base.Agtype;
import org.postgresql.jdbc.PgConnection;

import java.sql.*;

public class Sample {
    static final String DB_URL = "jdbc:postgresql://localhost:5432/demo";
    static final String USER = "postgres";
    static final String PASS = "pass";

    public static void main(String[] args) {

        // Open a connection
        try {

            PgConnection connection = DriverManager.getConnection(DB_URL, USER, PASS).unwrap(PgConnection.class);
            connection.addDataType("agtype", Agtype.class);

            // configure AGE
            Statement stmt = connection.createStatement();
            stmt.execute("CREATE EXTENSION IF NOT EXISTS age;");
            stmt.execute("LOAD 'age'");
            stmt.execute("SET search_path = ag_catalog, \"$user\", public;");

            // Run cypher
            ResultSet rs = stmt.executeQuery("SELECT * from cypher('demo_graph', $$ MATCH (n) RETURN n $$) as (n agtype);");

            while (rs.next()) {

                // Returning Result as Agtype
                Agtype returnedAgtype = rs.getObject(1, Agtype.class);

                String nodeLabel = returnedAgtype.getMap().getObject("label").toString();
                String nodeProp =  returnedAgtype.getMap().getObject("properties").toString();

                System.out.println("Vertex : " + nodeLabel + ", \tProps : " + nodeProp);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Output

Vertex : Person, 	Props : {bornIn=Pakistan, name=imran}
Vertex : Person, 	Props : {bornIn=Pakistan, name=ali}
Vertex : Person, 	Props : {bornIn=US, name=james}
Vertex : Person, 	Props : {bornIn=Pakistan, name=ali}
Vertex : Person, 	Props : {bornIn=Pakistan, name=usama}
Vertex : Person, 	Props : {bornIn=Pakistan, name=akabr}
Vertex : Country, 	Props : {name=Pakistan}
Vertex : Country, 	Props : {name=US}

For more information about Apache AGE

• Apache Age : https://age.apache.org/
• GitHub : https://github.com/apache/age
• Document : https://age.apache.org/age-manual/master/index.html