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