import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.Properties; class JavaConnectorTest { private static final String CREATE_TABLE_SQL = "CREATE TABLE IF NOT EXISTS default.test1 (`age` Int32, `name` String, `int_nullable` Nullable(Int32)) Engine = Memory"; private static final String INSERT_SQL = "INSERT INTO default.test1(`age`, `name`) VALUES(33, 'jdbc'),(44, 'ck')"; private static final String SELECT_SQL = "SELECT * FROM default.test1"; private static final String SELECT_NUMBER_SQL = "SELECT * FROM system.numbers LIMIT 13"; private static final String DROP_TABLE_SQL = "DROP TABLE default.test1"; public static void main(String[] args) { int i = 0; String host = "127.0.0.1"; String port = "5432"; String user = "default"; String password = ""; String database = "default"; while (i < args.length) { switch (args[i]) { case "--host": host = args[++i]; break; case "--port": port = args[++i]; break; case "--user": user = args[++i]; break; case "--password": password = args[++i]; break; case "--database": database = args[++i]; break; default: i++; break; } } String jdbcUrl = String.format("jdbc:postgresql://%s:%s/%s", host, port, database); Connection conn = null; Statement stmt = null; Properties props = new Properties(); props.setProperty("user", user); props.setProperty("password", password); props.setProperty("preferQueryMode", "simple"); props.setProperty("sslmode", "disable"); try { conn = DriverManager.getConnection(jdbcUrl, props); stmt = conn.createStatement(); stmt.executeUpdate(CREATE_TABLE_SQL); stmt.executeUpdate(INSERT_SQL); ResultSet rs = stmt.executeQuery(SELECT_SQL); while (rs.next()) { System.out.print(rs.getString("age")); System.out.print(rs.getString("name")); System.out.print(rs.getString("int_nullable")); System.out.println(); } stmt.executeUpdate(DROP_TABLE_SQL); rs = stmt.executeQuery(SELECT_NUMBER_SQL); while (rs.next()) { System.out.print(rs.getString(1)); System.out.println(); } stmt.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); System.exit(1); } } }