I followed the following tutorial: Using WebSocket to build an interactive web application Everything works as described and aplication looks fine. I just have a nice controller: And a bit configuration. Now I want to add security for this simple application. I spent time to find an example but I could not fi…
Storing UUID as string in mysql using JPA
I came across a blog of using UUID with Hibernate and MySql. Now the problem is, whenever I take a look at the database the ID’s will be non-readable format (binary-16). How can I store UUID as a readable format like 7feb24af-fc38-44de-bc38-04defc3804fe instead of ¡7ôáßEN¹º}ÅÑs I was using this code And…
java.sql.SQLException: Unknown system variable ‘query_cache_size’
I have a app running with JDBC and get data from MySQL, but I can’t build it because of this error : I have file application.properties here Mysql workbench is 8.0 version Answer query_cache_size was removed in MySQL 8. Check the docs. It works with JDBC driver 5.1.44.
confused about java looping
I just started learning programming and java is my first language. I’ve come across an exercise involving for loop, I’d like to know how the result is found: the output is: 17 I know this is a silly basic question but I really need to understand how the result is 17. Answer In your loop : the i st…
RecyclerView Item Click Listener the Right Way
I use RecyclerView adapter to display data inside an activity, I want to implement onClickListener inside the activity, currently, I am setting onClickListener inside adapter as usual which works fine. However I want to implement it inside activity so I have greater control. This doesn’t serve my purpos…
how to get string from string.xml in adapter class on click method
I want to get string in my adapter class on view holder in on click method my app crash when i implement the code write below in on click if(postion==1). Answer If you look at the docs you’ll see that Resources.getSystem().getStrings will provide you with system wide strings, not the ones in your applic…
Parameterize both class and tests in JUnit 5
Is there a way to parameterize both test class (like you could do with Parameterized and @Parameters in JUnit 4) and test methods (like you could do with JUnitParams in JUnit 4 or with @ParameterizedTest in JUnit 5)? I need to get the Cartesian product of the parameters in the end. Example of a partial test f…
How to force ANTLR to parse all input CharStream
I’m using ANTLR4 to parse a syntax file. When I use BaseErrorListener to detect errors, I got a problem. When faced with an illegal input string, ANTLR automatically matches the appropriate branch and then ignores the subsequent stream of characters even if it contains errors. And I want to detect that …
How read a PKCS8 encrypted Private key which is also encoded in DER with bouncycastle?
I have tried answers of these questions: Bouncy Castle : PEMReader => PEMParser Read an encrypted private key with bouncycastle/spongycastle However as my encrypted key is encoded in DER when I call object is null. I can convert it to PEM with this openssl’s command (it decrypts the key too) but I ne…
Page vs Slice when to use which?
I’ve read in Spring Jpa Data documentation about two different types of objects when you ‘page’ your dynamic queries made out of repositories. Page and Slice So, I’ve tried to find some articles or anything talking about main difference and different usages of both, how performance cha…