I have implemented a program that will print data into a pdf however I am facing this issue I know there have been similar issues posted but I could not find the solution to my problem from them. What I am doing is that I initialized two documents one of them being the main document(doc) the other for the res…
Tag: java
Creating a Windows auto restart + a counter that increments each reboot
I’m trying to set up a program to auto restart windows after boot as well as incrementing the amount of restarts that it has completed. I’ve written a small amount of code but it’s not even restarting the system itself when placed in the startup folder. You can see the command prompt very br…
JAXB – Unmarshalling of abstract classes (InstantiationException)
I know, that it might seem that this question is a duplicate of this one: InstantiationException during JAXB Unmarshalling (abstract base class, with @XmlSeeAlso concrete sub class) However, it is slightly different: We are using the maven-jaxb2-plugin to generate our Java-classes from xsd-files. You can find…
Thread join(1) usage in mutlithread wait-notify example in Java
I have example with wait-notify application which is invoked from main: } and invoker } As I expected “exception” message should be printed as I join(1) to threads and wait them to die only 1 mills, but they are sleeping more than that. What am I missing? Answer join(1) has 3 ways ‘out’…
Create a list with only base class elements
In Java I have a class and subclass Now let’s say I have List<Bar> bars. How can I create from this a List of Foo (and I only want the a field to appear, not b) Answer What you want is impossible; let’s say you have your bars list which contains 5 Bar instances. It is not possible in java
How can we know whether an object is marked as garbage by GC?
Is there any tool to visualize the status of GC on a specific object? Answer If you can access the object, it is trivially not collectable. The JVMTI system (Java Virtual Machine Tool Interface) lets other processes link up to a JVM and get stats from it. It’s what debuggers and profilers use; visualvm …
Unchecked assignment: ‘java.util.List’ to ‘java.util.Collection’
I am having an adapter where i have two lists one list is for InvestorsList where it comes with the list of investors and the other list is called investorListFull which is used to filter results when searching. Below is how i have declared the lists Below is how the lists are assigned in my recyclerview adap…
How to make context not null in onCreate()?
I’m trying to get the context in the onCreate() method, to use in my RoomDb repository, but it keeps giving me a NullPointerException. repository I’ve tried to look through other explanations, but I just can’t wrap my head around it. I’ve tried GetApplicationContext, and this. I’…
ArrayList.get() function in Java requires int for index instead of the desired long
The problem in my code is following: enen if I autobox to <Long>, Java requires to cast to int when I use listOfPrimes::get. It is not desired because the numbers I would work with would be out of scope. How can I fix that? Answer In this loop You should change the type of i from long to int. This
ReferenceError: LE1DOWNmachen is not defined
I wrote it in one of the hmi design programs. It´s IoT software. After connecting with the source (my fall Siemens Logo 8) – PLC hardware, I get the ReferenceError, when I click on every button. These are my triggers to fire up the function. They are connected to start the animation. What should I chang…