I don’t understand the difference between setAttribute( ) and addAttribute( ) in GraphStream1.3. In GraphStream’s Element API 1.3 it’s explained that setAttribute is Like addAttribute() but for consistency. what does it means? Answer It is most likely that they mean api consistency with this…
Tag: java
Which choice is better for generating equals() and hashCode() methods in Hibernate?
I create equals() and hashCode() methods in each Hibernate entity (if there is no inheritance) in my Java app. However, I am a little bit confused and wanted to be sure if I define it properly. Could you please clarify the following issues? In IntelliJ, when I use the “Generate” feature (via Alt +…
Why the constructor is invoked?
I am new to Spring. Recently I encountered something weird, I was using @Autowired for Auto Injecting Name, Emotion in Person class(I have a different class for each Name, Emotion, Person). I encountered that the Person constructor was getting invoked even if I have not used @Autowired with it. Can anyone exp…
Spring Boot & Thymeleaf – Localized text does not appear
I am currently working on the localization of my (second) Spring Boot project. However, I have come to a halt after several hours of struggling: I am unable to get a user-editable Session localization. The problem appears to occur as soon as the user sends a GET request with the lang parameter. (travel down b…
Adding external jar dependency in JAR file
Backgorund : I am trying to add UserStorageSPI for my legacy application, so that we can use existing user credentials to log in. I have followed this tutorial, and the full source code for the sample application is available here. This application is storing plaintext passwords and compares them directly. Ho…
Refreshing configurations of microservices based on messaging topic
I have a spring cloud configserver in place and we are using s3 as a version control. I have activemq for sending topics which will later be consumed by the microservices. Now we need to refresh the configuration of microservices depending upon the value of the topic which we send in activemq. Lets say we onl…
Why assigning instance variable to local variable?
This is something I see in Spring Boot code for example (in the catch block with webServer variable): Why not just doing this.webServer.stop()? What is the purpose of local variable webServer? Answer The main purpose of the assignment is to avoid producing a NullPointerException when the this.webServer is set…
JPA Using Composite Fields To Store Multiple @Column On An @Entity
I have a user table and I am using Hibernate to read it into User instances. I want to collect a number of related columns under a composite object to pass it around. So, I want to do something like this: Now I want to read some of the columns in the same user table into the fields in my
No qualifying bean of type ‘org.springframework.boot.actuate.metrics.MetricsEndpoint’
I upgraded spring.version from 5.0.18.RELEASE to 5.3.21 and spring.boot.version from 2.1.18.RELEASE to 2.7.0 spring-boot-starter-actuator ${spring.boot.version} In my Healthcheck class I use: After upgrade I’ve got: Why Spring doesn’t see org.springframework.boot.actuate.metrics.MetricsEndpoint ? …
Json deserialization Java
i have a simple question, let’s say I have this json Mapped this way: I was wondering if it was possible to just save an outer field in the inner object like this by using some custom setter/annotation or something: PS: using a custom deserialization is my last resort due to the complexity of the json A…