Consider the following two snippets of code on an array of length 2: boolean isOK(int i) { for (int j = 0; j < filters.length; ++j) { if (!filters[j].isOK(i)) { return false; } } return true; } and boolean isOK(int i) { return filters[0].isOK(i) && filters[1].isOK(i); } I would assume that the performance of these … Read more
We have a Java listener that reads text messages off of a queue in JBossMQ. If we have to reboot JBoss, the listener will not reconnect and start reading messages again. We just get messages in the listener’s log file every 2 minutes saying it can’t connect. Is there something we’re not setting in our … Read more
I’m looking to have text display vertically, first letter at the bottom, last letter at the top, within a JLabel. Is this possible? Answer I found this page: http://www.java2s.com/Tutorial/Java/0240__Swing/VerticalLabelUI.htm when I needed to do that. I don’t know if you want the letters ‘standing’ on each other or all rotated on their side. /* * … Read more
Maybe the most typical example is the JDBC closing done wrong way and not handling the possible exceptions correctly. I am very curious to see other examples you have seen – preferably web application related. So, are there any common leak patterns in Java? Answer The two key “effective leak” patterns in my experience are: … Read more
I am trying to understand what’s the correspondent of servlets and applets in .NET but I don’t have much experience in JAVA. I am thinking applets could be compared to the silverlight stuff, meaning you code independently from the browser, but then it’s not like that since (between other things) you can re-use an applet … Read more
I’m not really sure if it’s a good design decision to make the validators validate commands based on the state of the database. For example if I need to validate a User bean besides checking if the email and username are empty etc. I also need to reject values if they are already used. Should … Read more
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Stack Overflow. Closed 2 years ago. Improve this question While cyclomatic complexity is a worthwhile metric, I tend to find it to be a poor tool for identifying … Read more
I am new at Hibernate, and I have a question regarding HQL Left join. I try to left join 2 tables, patient and provider, and keep getting “Path expected for join!” error on the second table. Appreciate it if anybody can help on this issue! Here is the mapping of the 2 tables/classes: patient.hbm.xmL: <?xml … Read more
Is it correct to assume a Java object only takes up the 8 bytes for the object reference as long as all it’s members are set to null or does the definition of members already use up space in the instance for some reason? In other words, if I have a large collection of objects … Read more
I’m trying build a method which returns the shortest path from one node to another in an unweighted graph. I considered the use of Dijkstra’s but this seems a bit overkill since I only want one pair. Instead I have implemented a breadth-first search, but the trouble is that my returning list contains some of … Read more
