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Tag: java

In Hotspot JVM, why CDS needs Compressed Oops?

I read this post “https://malloc.se/blog/zgc-jdk15”, and last index is about Class Data Sharing. In this index, This feature(means CDS) only work when the Compressed Oops feature was enable(-XX:+UseCompressedOops). I know about CDS and Compress Oops a little, but I cant understand about their rela…

Best way to convert an array of integers to a vector? in java

I have an array like So i wanted it convert it into an vector I did try and got this error Is there a way to change the types or a faster method than this? Answer NB: Before I answer the question, Vector is deprecated and should never be used. You’re looking for List. Whatever property Vector has that m…

Substring a string in JAVA

Is possible to substring this String = “D:/test/for test/change.txt:D:/test/for test/further.txt:D:/test/for test/yandex.txt” to: Because are two column, I can not split() use “:”. Answer A simple regular expression below splits on “:” that are followed by a “drivelet…

Criteria API how to write = ANY(?1) expression?

I have a query that I want to translate to Criteria API. A query After java processes it (native sql query) the final query looks like this My Question is how to translate = ANY(?1) part to Criteria API? I see that any() definition is How to put array of values to it? I’m using PostgreSQL Answer You wil…

Java bytecode – Why is offset being skipped?

I have this very simple class That i compiled with javac and then decompiled with javap to see its bytecode. Lets check offsets 0 – is reserved for “this” reference 1 – is the method parameter 2 – skipped ? 3 – variable “d” 4 – skipped ? 5 – variable…

How to assign to a new array an array of objects?

I can’t figure out how I would do the ff. I have the ff. Payload And I just want to get the acctId params and assign it to a new plain array of accountIds. How do I do it in Spring/Java?. Thanks Answer Try using json path. Library can be found here. E.g. say you had json like this: Actual

How to call a method twice in a row?

I have a code where in my class I would like to be able to call the method answer twice like qns.answer(5).answer(7). But right now when I call the method answer as below, I get the error cannot find symbol. For example: Would appreciate if you could kindly give some pointers on how to get around this. Answer…

GraphQL Input type declaration for Mutation

I’m new to GraphQL and after some coding I bumped into a problem with declaring an Input type for a Mutation. Here’s my Schema: When I run my app, I get the error Caused by: graphql.kickstart.tools.SchemaError: Expected type ‘IdInput’ to be a GraphQLInputType, but it wasn’t! Was …