Re: first connection attempt always fails, subsequent always succeed

Rob,

 

If this is obvious apologies, but have you explicitly included an appropriate JDBC driver in your .war build ?  https://jdbc.postgresql.org/download.html   I am currently fighting issues with MacOS apparently not allowing connections to be made (timeout or host not found) and have reverted to a 9.3 build for testing.

 

Are you using NetBeans  as your IDE ?

 

David Gradwell

 

From: Rob Sargent <robjsargent@gmail.com>
Date: Thursday, 12 November 2020 at 18:59
To: "pgsql-jdbc@lists.postgresql.org" <pgsql-jdbc@lists.postgresql.org>
Subject: first connection attempt always fails, subsequent always succeed

 

This is an embedded tomcat application, not full-blown apache server.  Works great when it does...  I haven't wired in a connection supplier yet since (for now) there are few clients and they do two reads and one write, all very large.

java:

java -version
openjdk version "11.0.9" 2020-10-20
OpenJDK Runtime Environment (build 11.0.9+11-Ubuntu-0ubuntu1.20.04)
OpenJDK 64-Bit Server VM (build 11.0.9+11-Ubuntu-0ubuntu1.20.04, mixed mode, sharing)

tomcat: 

version 9.0.39

poostgres:

PostgreSQL 12.4

This is the servlet's connection code:

String templateUrl = System.getProperty("SGSSVR_databaseConnection", "jdbc:postgresql://%s/%s"); //host(with :port) / dbname

String fullurl = String.format(templateUrl, dbhost, dbname);  //will add port to this next

conn = DriverManager.getConnection(fullurl, dbrole, magicPassword);

dsl = DSL.using(conn, SQLDialect.POSTGRES);

which generates this stack trace, showing what looks to me like a good url (and which works later).

java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost/version4007
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:702)

thinking these forums like bottom posting

From my war file (which I explode)

WEB-INF/lib/postgresql-42.2.18.jar

I get the same behaviour running from within IntelliJ and from gradle/command-line, on ubuntu 20.04