Tag: java

Java CSV parser with string separator (multi-character)

Is there any Java open source library that supports multi-character (i.e., String with length > 1) separators (delimiters) for CSV? By definition, CSV = Comma-Separated Values data with a single character (‘,’) as the delimiter. However, many other single-character alternatives exist (e.g., tab…

Guava cache and preserving checked exceptions

caching checked-exceptions exception guava java

I’m refactoring some code to use guava Cache. Initial code: In order not to break something I need to preserve any thrown exception as is, without wrapping it. Current solution appears somewhat ugly: Is there any possible way to make it nicer? Answer Just after writing the question started thinking abou…

Java: Rotating Images

graphics2d image java rotation swing

I need to be able to rotate images individually(in java). The only thing I have found so far is g2d.drawImage(image, affinetransform, ImageObserver ). Unfortunately, I need to draw the image at a specific point, and there is no method with an argument that 1.rotates the image separately and 2. allows me to se…

declare multiple arraylists

java

is it possible to declare 2 array lists in the same line? e.g: Is it then possible to do something like: Obviously, I get a compile error when I do the above, and was wondering how could one declare 2 lists in the same line. Answer If you want that, you should do:

Retrieve test name on TestNG

java testng

Can I retrieve currently running test name like in JUnit (using getName() or rules)? P.S. I don’t want use some self-written tool based on stack traces. Answer According the to TestNG documentation at: http://testng.org/doc/documentation-main.html you can implement listeners that might be able to help y…

Android Resources Class Memory Usage

android heap-memory java memory-management

I’m making modifications to the Android 4.0 launcher and I have been running into many OutOfMemoryErrors. Since the 4.0.3 update it got much worse (or started, it seems before it was fine, but I never got to test properly) and I have tried many many things to fix it. The error is also in the stock launc…

Java Delay/Wait

delay java loops notify wait

How do I delay a while loop to 1 second intervals without slowing down the entire code / computer it’s running on to the one second delay (just the one little loop). Answer

How does Java deal with multiple conditions inside a single IF statement

java

Lets say I have this: Now. Is Java smart enough to skip checking bool2 and bool3 if bool1 was evaluated to false? Does java even check them from left to right? I’m asking this because i was “sorting” the conditions inside my if statements by the time it takes to do them (starting with the ch…

Java visitor pattern instead of instanceof switch

java visitor-pattern

In this question it is said I can use visitor pattern instead of a bunch of instanceofs. Jmg said “If you are not free to change A, B, and C, you could apply the visitor pattern to achieve the same.” As far as I understand I still have to make A, B and C support visitor (have an accept() method,

Different names of JSON property during serialization and deserialization

jackson java json

Is it possible: to have one field in class, but different names for it during serialization/deserialization in Jackson library? For example, I have class “Coordiantes”. For deserialization from JSON want to have format like this: But when I will serialize object, result should be like this one: I …