add postgresql listener

This commit is contained in:
Jörg Prante 2023-04-27 16:37:07 +02:00
parent 6127f11914
commit c6e4c7e940
2 changed files with 54 additions and 0 deletions

View file

@ -4,6 +4,7 @@ import org.xbib.jdbc.postgresql.Postgresql;
module org.xbib.jdbc.postgresql {
requires org.xbib.jdbc.query;
requires java.sql;
requires org.postgresql.jdbc;
uses Flavor;
exports org.xbib.jdbc.postgresql;
provides Flavor with Postgresql;

View file

@ -0,0 +1,53 @@
package org.xbib.jdbc.postgresql;
import org.postgresql.PGNotification;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.function.Consumer;
public class Listener implements Runnable {
private final Connection connection;
private final org.postgresql.PGConnection pgConnection;
private final Consumer<PGNotification> notificationConsumer;
private final Consumer<Throwable> errorConsumer;
public Listener(Connection connection,
Consumer<PGNotification> notificationConsumer,
Consumer<Throwable> errorConsumer) throws SQLException {
this.connection = connection;
this.pgConnection = (org.postgresql.PGConnection) connection;
this.errorConsumer = errorConsumer;
this.notificationConsumer = notificationConsumer;
try (Statement stmt = connection.createStatement()) {
stmt.execute("LISTEN event");
}
}
@Override
public void run() {
while (true) {
try (Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT 1")) {
} catch (SQLException e) {
errorConsumer.accept(e);
}
try {
PGNotification[] notifications = pgConnection.getNotifications();
if (notifications != null) {
for (PGNotification notification : notifications) {
notificationConsumer.accept(notification);
}
}
} catch (SQLException e) {
errorConsumer.accept(e);
}
}
}
}