I’m storing two dates in the PostgreSQL database. First, is the data of visit of a webpage, and the second date is the date of last modification of the webpage(this is get as a long). I have some doubts what is the best strategy to store these values. I only need day/month/year and hour:seconds and this…
Tag: java
VisualVM Not showing ANY methods called for CPU Performance Profiling
I’m running a Java 1.6_21 SDK build app. Its been build in Eclipse, and i’m using the VistualVM eclipse plugin to launch VisualVM when the app starts. When I go to the Profile tab and click CPU profiling, It only shows the THREADS that are running, but it doesn’t show any METHOD calls. Quite…
Most efficient way to convert a single char to a CharSequence
What’s the most efficient way to pass a single char to a method expecting a CharSequence? This is what I’ve got: According to the answers given here, this is a sensible way of doing it where the input is a character array. I was wondering if there was a sneaky shortcut I could apply in the single-…
Java seek a method with specific annotation and its annotation element
Suppose I have this annotation class So is there a way to look into an object, “seek” out the method with the @MethodXY annotation, where its element x = 3, y = 2, and invoke it? Thanks Answer Here is a method, which returns methods with specific annotations: It can be easily modified to your spec…
Android: location; activity and service
I’m working on some application that should fetch current location and after device is located in some radius should be shown application with some message. I have a few questions. I’m trying to fetch location using If I use requestLocationUpdates then GPS is always working. And this is a waste of…
Java override abstract generic method
I have the following code However I don’t know how to do this, as I cannot override doEventStuff with something specific. Does anyone know how to do this? Answer It’s not really clear what you’re trying to do, but perhaps you just need to make Event itself generic:
How to create a polygon in JTS when we have list of coordinate?
We can create a LineString using coordinates list like this: How can we create a polygon using coordinates list? Thanks in advance. Answer Use these line of codes: I hope it will help 🙂
In Java, what is the fastest way to get the system time?
I’m developing a system that often use the system time because the Delayed interface. What is fastet way to get the time from system? Currently I’m using Calendar.getInstance().getTimeInMillis() every time I need to get the time, but I don’t know if there is a faster way. Answer System.curre…
Head First Design Patterns – Combined Pattern
I’m reading the chapter 12 on the Combined Pattern in Head First Design Patterns. On page 541,the sample DJView,it cant’t run correctly in my computer.when i press the ‘start’, the program only sounds once rather than circularly . i’m not sure whether because of the environment o…
Conversion from 12 hours time to 24 hours time in java
In my app, I have a requirement to format 12 hours time to 24 hours time. What is the method I have to use? For example, time like 10:30 AM. How can I convert to 24 hours time in java? Answer Try this: which produces: See: http://download.oracle.com/javase/1.5.0/docs/api/java/text/SimpleDateFormat.html