I’m using a DrawerLayout for the navigation of my app: Taking this menu for the example: I’d like the Home button to launch the HomeActivity and so on. But clearing the activity stack, that is: If I press People, then Photos, then Locations and then the back button, the app should close. I’m…
Fullscreen WebView when landscape?
I’m trying to build an app with a webview which should go fullscreen when the orientation changes to landscape. I did the way with layout-land and main.xml where I just gave the WebView fill_parent and it was over all the other views. The problem with that was, that the WebView was lagging. I hope there…
Custom Edge with jgrapht
I want to define a custom edge But when I try to use the super()is that possible? What should I use for EdgeFactory when creating a graph? Would this be sufficient? Or should I create a new class who extends EdgeFactory as well? Answer You do not require to subclass DefaultWeightedEdge to create your custom e…
Completely expand all node of a Jtree (including children)
I found some details on the internet for this problem but the solution does not seem to work. I want to be able to expand all the nodes ( including the leaf nodes ) of a JTree. This is the code I have …
Can a object be private and public?
Can a reference to an object be private in class while other object can have a public reference to the same class(post script: new to java+ a simple example please). I read somewhere that this prob is regarding aliasing? Sorry my title may not make sense! Answer Objects aren’t private or public. Fields …
Why is this called backtracking?
I have read in Wikipedia and have also Googled it, but I cannot figure out what “Backtracking Algorithm” means. I saw this solution from “Cracking the Code Interviews” and wonder why is this a backtracking algorithm? Answer “Backtracking” is a term that occurs in enumeratin…
High memory usage when using Hibernate
I code a server side application with java run on linux server. I use hibernate to open session to database, use native sql to query it and always close this session by try, catch, finally. My server query DB using hibernate with very high frequency. I already define MaxHeapSize for it is 3000M but it usually…
Log4J creates log file but does not write to it
I’m trying to configure log4j to log messages to a file. Right now, the file does get created with the name I provide, but the logs are not written to the file. My code: Contents of my log4j.properties file: When I run this, I get this output in the console: The file log.log does get created in my main …
Get month number from month name
I have this. How to get month number which contain in monthName variable? Thanks! Answer Use Java’s Calendar class. It can parse any given string into a valid calendar instance. Here is an example (assuming that the month is in english). You can specify the language in SimpleDateFormat: By default, Java…
How to convert a multipart file to File?
Can any one tell me what is a the best way to convert a multipart file (org.springframework.web.multipart.MultipartFile) to File (java.io.File) ? In my spring mvc web project i’m getting uploaded file as Multipart file.I have to convert it to a File(io) ,there fore I can call this image storing service(…