The javadoc for StandardWatchEventKinds.ENTRY_MODIFY says: Directory entry modified. When a directory is registered for this event then the WatchKey is queued when it is observed that an entry in the directory has been modified. The event count for this event is 1 or greater. When you edit the content of a fi…
JDBCTemplate set nested POJO with BeanPropertyRowMapper
Given the following example POJO’s: (Assume Getters and Setters for all properties) One can easily query a database (postgres in my case) and populate a list of Message classes using a BeanPropertyRowMapper where the db field matched the property in the POJO: (Assume the DB tables have corresponding fie…
How to redirect ProcessBuilder’s output to a string?
I am using the following code to start a process builder.I want to know how can I redirect its output to a String. I tried using ByteArrayOutputStream but it didn’t seem to work. Answer Read from the InputStream. You can append the output to a StringBuilder:
JUnit instantiating object every time a test case method runs
Test case: import static org.junit.Assert.assertTrue; import org.junit.Test; public class PendingTest { PendingUtil pendingUtil = new PendingUtil(); boolean result; @…
Populating a List with a contiguous range of integers
I’d like to have a list which contains the integers in the range 1 to 500. Is there some way to create this list using Guava (or just plain Java) without having to loop through the range and add the values individually within my own code? Answer Using Guava, you can resort to a Range: https://guava.dev/…
Changing the directory path’s forward slash to backslash
I’m using the JFile chooser, and trying to import a pdf file but; System.out.println(filelist); perfectly prints the desired outcome with forward slashes; C:/Users/raz/Documents/2pg.pdf but the doc gives an error with backslashes; java.io.FileNotFoundException: C:UsersrazDocuments2pg.pdf (The filename, …
Struts 2 workflow interceptor and actions that do not have an INPUT result
If I understand, the Struts 2 interceptor stack correctly, the workflow interceptor looks to see if any validation failures have been reported by the validation interceptor. If it finds that there have been validation failures, it returns ( by default ) Action.INPUT If this is the case, what happens if the Ac…
What is an instance variable in Java?
My assignment is to make a program with an instance variable, a string, that should be input by the user. But I don’t even know what an instance variable is. What is an instance variable? How do I create one? What does it do? Answer Instance variable is the variable declared inside a class, but outside …
Creating a temporary copy of a Calendar object in Java
I need to figure out how to create a temporary Calendar object (a copy of a “permanent” calendar that already exists) so that I can manipulate the copy: tempCal.add(unit, value). I need to …
Unable to resolve reverse routing methods in IntelliJ
I’m following one of the play framework tutorials, but I’m getting compile errors whenever I try to use reverse routing. Firstly, where the error shown in intelliJ is ‘cannot resolve method javascriptRouter(java.lang.String, ?, ?, ?, ?)’ But also in the a unit test: where it cannot res…