HikariCP Issue#828

Issue828.java

package com.zaxxer.hikari.pool;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.junit.Test;
import org.postgresql.PGConnection;

import com.zaxxer.hikari.HikariDataSource;

public class Issue828
{
   private HikariDataSource hikariDataSource;

   @Test
   public void issue828() throws ClassNotFoundException, SQLException, InterruptedException
   {
      Class.forName("org.postgresql.Driver");
      String url = "jdbc:postgresql://localhost:5432/test";

      // Connection lConn = DriverManager.getConnection(url, "brettw", "");
      Connection lConn = getDBConnection(url).unwrap(Connection.class);

      System.out.println("lConn: " +lConn.toString());

      // Create two threads, one to issue notifications and
      // the other to receive them.
      Listener listener = new Listener(lConn);
      Notifier notifier = new Notifier(lConn);
      listener.start();
      notifier.start();

      notifier.join();
   }

   private Connection getDBConnection(String jdbcUrl) throws SQLException
   {
      hikariDataSource = new HikariDataSource();
      hikariDataSource.setJdbcUrl(jdbcUrl);

      return hikariDataSource.getConnection();
   }

   static class Listener extends Thread {
      private Connection conn;
      private org.postgresql.PGConnection pgconn;

      Listener(Connection conn) throws SQLException {
          this.conn = conn;
          this.pgconn = conn.unwrap(PGConnection.class);
          Statement stmt = conn.createStatement();
          stmt.execute("LISTEN new_facility_added");
          stmt.close();
      }

      public void run() {
          for (int i = 0; i < 40; i++) {
              try {
                  // issue a dummy query to contact the backend
                  // and receive any pending notifications.
                  Statement stmt = conn.createStatement();
                  ResultSet rs = stmt.executeQuery("SELECT 1");
                  rs.close();
                  stmt.close();

                  org.postgresql.PGNotification notifications[] = pgconn.getNotifications();
                  if (notifications == null) {
                      System.out.println("Got no notification");
                  } else {
                      for (int j = 0; j < notifications.length; j++) {
                          System.out.println("Got notification: " + notifications[j].getName());
                      }
                  }

                  // wait a while before checking again for new
                  // notifications
                  Thread.sleep(1000);
              } catch (SQLException sqle) {
                  sqle.printStackTrace();
              } catch (InterruptedException ie) {
                  ie.printStackTrace();
              }
          }
      }
   }

   static class Notifier extends Thread {
      private Connection conn;

      public Notifier(Connection conn) {
          this.conn = conn;
      }

      public void run() {
         for (int i = 0; i < 20; i++) {
              try {
                  Statement stmt = conn.createStatement();
                  stmt.execute("NOTIFY new_facility_added");
                  stmt.close();
                  Thread.sleep(2000);
              } catch (SQLException sqle) {
                  sqle.printStackTrace();
              } catch (Exception ie) {
                  ie.printStackTrace();
              }
          }
      }
   }
}