I get this error when I try to do anything with Java in command prompt: I did screw around with deleting Java directories and registry a few days ago. I restarted computer and java was still working fine, then i restarted it again today and now I get this error. I have tried uninstalling and reinstalling but …
Tag: java
How to get Scala List from Java List?
I have a Java API that returns a List like: I am using the below scala code: Now if I try scala syntax sugar like: it does not work. I get the error: It seems I need to convert Java List to Scala List. How to do that in above context? Answer EDIT: Note that this is deprecated since 2.12.0.
Bitwise operator for simply flipping all bits in an integer?
I have to flip all bits in a binary representation of an integer. Given: The output should be What is the bitwise operator to accomplish this when used with an integer? For example, if I were writing a method like int flipBits(int n);, what would go in the body? I need to flip only what’s already presen…
How to use Jackson to deserialise an array of objects
The Jackson data binding documentation indicates that Jackson supports deserialising “Arrays of all supported types” but I can’t figure out the exact syntax for this. For a single object I would do this: Now for an array I want to do this: Anyone know if there is a magic missing command? If …
Remove row being edited from JTable
I have a JTable and a button next to it that calls deleteSelectedRows(), which does exactly what it sounds like: But if a cell was in the act of being edited when it (and/or cells above it) were deleted, the edited cell stayed while the rest left, like this: And then trying to exit out of the editing threw an
Deserializing JSON into object with overloaded methods using Jackson
I am attempting to deserialize a JSON object stored in CouchDb using Jackson. This object needs to deserialize into a pojo that contains overloaded methods. When I attempt to retrieve the object from couch and do the deserialization I get the following exception: org.ektorp.DbAccessException: org.codehaus.jac…
java executing bash script, error=26 Text file busy
I’ve got a java code that is writing a Linux bash script out, then doing a chmod to add execute permission, then trying to execute it. I’m getting an IOException during the start of the process saying error=26, Text file busy. I’ve verified that the file is finished being written and the str…
Trust Store vs Key Store – creating with keytool
I understand that the keystore would usually hold private/public keys and the trust store only public keys (and represents the list of trusted parties you intend to communicate with). Well, that’s my first assumption, so if that’s not correct, I probably haven’t started very well… I wa…
Automatically generate HTML pages in Java
I am developing a Java desktop application. I have a need to create HTML pages through my application. When the user clicks on View in Browser button a HTML page should be created with some details and shown it to the user. Is there a way I can do this? Is there are any resources I can use in this
Does any JVM implement blocking with spin-waiting?
In Java Concurrency in Practice, the authors write: When locking is contended, the losing thread(s) must block. The JVM can implement blocking either via spin-waiting (repeatedly trying to acquire the lock until it succeeds) or by suspending the blocked thread through the operating system. Which is more effic…