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Category: Questions

Java concurrent programming – endless loop

I am reading the book Introducing Play Framework: Java Web Application Development (ISBN 978-1-4842-5645-9) and there is this example on Callable: My question is, if the computation of the Future throws and exception, will the while loop run forever? In my opinion, yes, it will loop forever. First, if the Future computation throws an exception, then future.isDone() always evaluates to

Moving character efficiently on a row

Given input (items = 6, position = 3) creates a row of 6 items and a character positioned on item 3 {0,1,2,[3],4,5} A call to left() moves the character two positions to the left and the item at position 3 is removed {0,[1],2,4,5} The next call to right() moves the character two positions to the right and the item at

Extraneous input ” expecting {‘ ‘, ‘} – Antlr4

I have a text file which am parsing through antlr4. Text format Grammar Rules I get this What am i doing wrong and how could i make these rules better? Answer Your example input get properly parsed if you start with the init rule: prints: which looks like this indented: My guess is that the error you’re getting is produced

Jax-rs annotation Path is not work in java spring boot?

I have spring boot application with starter version 2.1.16, and spring-boot-starter-web dependency. So, i want use javax.ws.rs-api library, and add dependency: So when i create controller, and add @Path, @Get – i don’t get answer from the server (404 not found). How makes it work? Answer Add the following dependency in your pom.xml if you use spring boot starter version

Error while querying tables using hibernate

I am trying to query a table called student in MySQL. This is the structure: Here is the java code which I use to query: This is the error message: Here is the image of the referenced libraries: Insertion into table is working correctly. Only querying isn’t. What is the error here? Please comment if extra information is needed. UPDATE: