What is the “easiest” way for you to create a singleton (with exactly one element) Objects array in Java ? Answer
Tag: java
How do I get the file extension of a file in Java?
Just to be clear, I’m not looking for the MIME type. Let’s say I have the following input: /path/to/file/foo.txt I’d like a way to break this input up, specifically into .txt for the extension. Is there any built in way to do this in Java? I would like to avoid writing my own parser. Answer …
How to round time to the nearest quarter hour in java?
Given today’s time e.g. 2:24PM, how do I get it to round to 2:30PM? Similarly if the time was 2:17PM, how do I get it to round to 2:15PM? Answer Rounding You will need to use modulo to truncate the quarter hour: As pointed out by EJP, this is also OK (replacement for the last line, only valid if the
Wicket vs Vaadin
I am torn between Wicket and Vaadin. I am starting a micro-isv and need to make a choice of web framework. I have narrowed down my choices to Wicket and Vaadin. I have used both frameworks and I love them both. however I need to make a choice. If If I choose Vaadin: I wont have to worry much about
Automatically update jar files
I am currently working on desktop software based on java.It’s quite a big code base (more than 40 jar files). I wish to provide an automatic update functionality. The desktop software constantly checks one back end system to see if there are new versions of the jar files available. The problem now is: H…
TableModelListener and multiple column validation
This is the first time for me to post here, so sorry if I made some mistake. I am working on a JTable which column data have to verify some parameters, for example: Column 3 values > 30 Column 4 values > 10 Column 5 values > 4 Also the first 2 columns are filled “automatically”, putting 0…
What type of data structure should I use to hold table rows?
I’m new to Java and just getting into querying databases. So far I have my results in a ResultSetMetaData. I’m think that for each row in the dataset I should add it to some form of collection? Can anyone tell me the best practice for this? Thanks, Jonesy Answer Usually we have a class with fields…
java.sql.SQLException: Exhausted Resultset
I get the error java.sql.SQLException: Exhausted ResultSet to run a query against an Oracle database. The connection is via a connection pool defined in Websphere. The code executed is as follows: I note that the resultset contains data (rs.next ()) Thanks Answer I’ve seen this error while trying to acc…
Calling super super class method
Let’s say I have three classes A, B and C. B extends A C extends B All have a public void foo() method defined. Now from C’s foo() method I want to invoke A’s foo() method (NOT its parent B’s method but the super super class A’s method). I tried super.super.foo();, but it’s…
Differences among various bool types?
What are the differences among bool, boolean and Boolean in Java/Android? Answer bool does not seem to exist, at least I can’t find references to it. boolean is a primitive boolean type, not an object. Boolean is the wrapper object for a boolean.