I understand that when the Eden is full, a minor garbage collection is done. Surviving objects go to the survivol spaces. These objects will eventually arrive to the old generation. Does the objects in the survivol spaces get garbage collected as well, or they will just be moved to the tenure generation and b…
Tag: java
delete where all keys of a map are contained in a list in mongodb
I have this: A field which is a map where the keys are UUIDs and the value another object which is not relevant. A list of UUIDs that should be passed as parameter. I want to: delete from the collection all documents where all keys of the map are included in the list of UUIDs The object: With derived queries
type=search_phase_execution_exception, reason=all shards failed when i send ‘/’
I’m using elasticSearch with RestHighLevelClient and Java. When I put query: QueryBuilder qb = new QueryStringQueryBuilder(“” + valueSearch.toLowerCase() + “”). Where valueSearch contain “/” -> example REC2/. The searchResponse = client.search(searchRequest, Reques…
Thread-safety of int field in Java
If class has field with int type (not Atomic Integer and without volatile keyword) and all access to this field happens under read/write locks – will this field thread-safe in this case? Or in some moment some thread can see not real value of this field but something from cache? Answer Get answer from @…
are there any pitfalls when return @Entity from @RestController instead of DTO?
are there any pitfalls when return @Entity from @RestController instead of DTO ? like this: Answer I’d say yes. By returning an entity, you are going to have tight coupling of your response contract and the database entity. So in future if you want to make modifications to either your response/entity, y…
Why do we initially set min and max to the first value in the array when trying to find the minimum and maximum value?
I’ve been learning Java for a while and I’ve run into a problem I can’t figure out. I am currently learning arrays and how to iterate through them using loops. I generally understand how the if statement and the for loop work, but in this case I don’t understand the principle of this l…
Upgrade Jackrabbit 2.1.6 to Jackrabbit 2.20.6
I need to update the jackrabbit version from 2.1.6 to 2.20.6, so I want to know the best way to do that. I saw that there is an option with importing/exporting data to XML ( https://jackrabbit.apache.org/archive/wiki/JCR/BackupAndMigration_115513344.html ), but I’m not sure how to do that. So’ if …
how to pick set joinpoints in specific methods in AspectJ
I’m developing an Advice and I want to make it advise only on field sets in specific methods. I tried cflow(pointcutForSpecificMethod()) && set(* *) pointcut expression but it picks field sets in other methods under control flow of specific methods. Any idea? Answer This is not possible directly…
Is CSRF token require for Rest API in Spring boot
I am creating a Rest API using Spring boot on back-end and React js on frontend . I have a login form on React , should I enable csrf token on login/register form or not . After user logs in that user will get access token which I will store in memory in React and Refresh token in http only
Android Room Relationship duplicating information
Having the weirdest issue here, all is working fine, except that my 1-to-M query is duplicating the data. Customer table Invoice table CustomerInvoice relation DAO If I debug my application, set a breakpoint to test the Room stuff, then use the ‘Evaluate’ feature in Android Studio, I do the follow…