Skip to content

Tag: java

How to set the classpath correctly in java

I need to compile and run simple code using the gson library, but I can’t use Maven, Gradle or the IDE. The directory contains Main.java and gson-2.9.0.jar javac -cp gson-2.9.0.jar Main.java works correctly and creates Main.class But when I run java -cp ./*: Main, I get I also tried the following comman…

Handle daylight savings time and representing UTC in Date object

I have a function which returns the current UTC time in Date object, simple. What we do is find current Instant of UTC, put it in Date object and return. Note: Local Host time here is New York/America. The problem we are now facing is that Date refuses to store March 13 2:02 AM, since the time doesn’t e…

Can an assignment statement cause a null-pointer exception?

This code snippet is reading camera picture Exif metadata using ExifInterface: Apparently, one particular picture has no or invalid datetime and .getDateTime() is returning null. In the code I assign it to a long, dt, and that results in the exception that is shown below. Of course, if I un-comment the null-c…

Easy sort list 2D by column

I’m quiet new in Java data manipulation so I need some help if someone have a some good tips. Actually, I want just to find a easy way to sort a 2D list. I create a list like this: And then I want to have a result sorted by the second element like: I tried something like Arrays.sort(A.toArray(), (int[]a…