This post provides some experiences from making a simple Java app (well, the actual app does something this is just a demo) that connects to Bitfinex to get the funding rates run as a GraalVM native image.
xChange is one of the most famous Java libraries for integrating with a large number of crypto exchanges. It provides a simple API that Continue reading
When using Infinispan (or any other jBoss library for that matter) and Logback in the same project you may end up getting this warning when running the project:
ERROR StatusLogger No log4j2 configuration file found. Using default configuration: logging only errors to the console
Maybe you log to a persistent storage and you may miss important error messages, because they are logged to the console.
Solution 1: Start the application with specific parameter
One solution is to add the following parameter when starting the application:
-Dorg.jboss.logging.provider=
slf4j
The relevant code is in org.jboss.logging.
Solution 2: Exclude log4j libraries from classpath
Another solution is to exclude all logging related classes from the classpath, as in org.jboss.logging.
When using gradle it is enough to add the following into build.gradle
configurations {
all*.exclude group: ‘org.apache.logging.log4j’
all*.exclude group: ‘org.apache.log4j’
all*.exclude group: ‘org.jboss.logmanager’
}
It’s been ages since I have posted some sample code. It’s mainly because I don’t have time to collect and post sample code anymore. This once was a bit more challenging and googling wasn’t help much, so now that I have some time I though I would post some sample code that achieves batch inserts with spring data.
For example this link:
http://forum.spring.io/forum/spring-projects/data/118203-bulk-insert-with-crudrepository indicated that I had to manually get the session and iterate/flush (which was true when using Spring/Hibernate/JPA). But when using the CRUDRepository it appears it’s much simpler.
Full code sample (maven project) can be found on github: https://github.com/cyrus13/anastasakis-net-sample-code/tree/master/spring-data-batch
You basically need to have the following elements:
@Id @GeneratedValue(generator = "generator") @GenericGenerator(name = "generator", strategy = "increment")
So enabling the query log in MySQL:
SET global general_log = 1; SET global log_output = 'table';
we can see the following mysql code is executed:
SET autocommit=0;
select max(id) from ExampleEntity;
SHOW WARNINGS;
select @@session.tx_read_only;
insert into ExampleEntity (exampleText, id) values
('de32bec8-1cf9-4f14-b816-0ab7a00b1539', 4),
('c0c85b32-eb2d-4a69-ade4-ac70ea94241c', 5);
commit;
SET autocommit=1;
Note: Don’t forget to stop logging statements into MySQL general log!
SET global general_log = 0;
I wanted to add the suffix of the day in Java (i.e. 1st, 2nd, 3rd, etc.). This is a small method that does the Job
public static String daySuffix(int dayOfMonth) {
switch (dayOfMonth) {
case 1:
case 21:
case 31:
return "st";
case 2:
case 22:
return "nd";
case 3:
case 23:
return "rd";
default:
return "th";
}
}
I spend quite a lot of time using Eclipse and the white background is not particularly helpful for my eyes. I wanted a Java theme which is more relaxing for my eyes (e.g. with black background). The solution is Continue reading