I am trying to insert 100,000 rows in a MYSQL table under 5 seconds using Hibernate(JPA). I have tried every trick hibernate offers and still can not do better than 35 seconds. 1st optimisation : I started with IDENTITY sequence generator which was resulting in 60 seconds to insert. I later abandoned the sequence generator and started assigning the @Id
Tag: java
Caused by: java.net.ConnectException: Connection refused: no further information: localhost/127.0.0.1:9300
I am developing a project from the link http://www.mkyong.com/spring-boot/spring-boot-spring-data-elasticsearch-example/ without any custom change yet. My concerns is how we can run this project ? Do I need to install anything ? pom.xml Answer It is pretty clear that you have missed some or all of the steps in section 5.1 of the example that you are following. The last of
Java Get Value from Object by Key Name
I have retrieved an object from Firebase and would like to access the values of it using the name of each field I would like the value for. In javascript, this would be something as simple as myObject.name to retrieve the name in the object. How can I do the equivalent in Java? Answer Try this: If you have a
Hamcrest When to use Is or equalTo
I’m new using hamcrest. While I’m discovering how to use it I have been a doubt about when to use is or equalTo. Is there any difference between is and equalTo, although it is conceptually or ocasionally? It seems to behave the same. Why do you would use one instead of the other? Answer The Javadoc for Matchers is pretty
Change Spring boot folder structure for source code and resources
How can I change the path where spring boot is looking for the source code and resources. I want to move from src/main to src/server/main. In pom I put: Error: Could not find or load main class ema.Application Answer Here is a sample build section of a POM that can be used to configure the directories. Below Sample:
Spring data JPA: how to enable cascading delete without a reference to the child in the parent?
Maybe this is an overly simple question, but I am getting an exception when I try to delete a user entity. The user entity: And I have an entity class which references a user with a foreign key. What I want to happen is that when the user is deleted, any PasswordResetToken objects that reference the user are also deleted.
GKE & Stackdriver: Java logback logging format?
I have a project running Java in a docker image on Kubernetes. Logs are automatically ingested by the fluentd agent and end up in Stackdriver. However, the format of the logs is wrong: Multiline logs get put into separate log lines in Stackdriver, and all logs have “INFO” log level, even though they are really warning, or error. I have
Which collections are supported by Hibernate @ManyToMany annotation
I used @ManyToMany annotation on a Set and it worked fine. When I used ArrayList instead of Set it throws exception: org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: com.kaushik.winnersoft.data.Student.enrolledCourses Is ArrayList not supported? Which all collection are supported by @ManyToMany annotation? Answer The supported interfaces are: You get the exception because you have
Java Collision detection between different classes
I am making a simple game about shooting enemies and avoiding obstacles, but I have a problem with detecting collisions because I’ve got a lot of classes for every type of game object (player,enemy,obstacle,drop,bullet, etc.). And it won’t work because a doesn’t have ‘pos’, etc, so how can I do it so it works for every class? I’ve read about
Performance of JavaFx Gui vs Swing
I wrote two simple programs, both draw the same Sierpinski Triangle: One program was implemented using swing, and one using javafx. There is a very significant performance difference, swing implementation being consistently much faster: (In this test case : Swing over 1 sec. Javafx over 12 seconds) Is it to be expected or is there something very wrong with my