SocketChannel is thread safe, so only one channel is need for communication between client and server. the channel served for read/write operations simultaneously But, if we using multi channels (more than one connections between the same client and server), will the io performance be improved ??? If can, why…
Capturing speaker output in Java
Using Java is it possible to capture the speaker output? This output is not being generated by my program but rather by other running applications. Can this be done with Java or will I need to resort to C/C++? Answer I had a Java based app. that used Java Sound to tap into the sound flowing through the system…
Creating a string attribute in Weka Java API
I’m trying to create a new string Attribute using Weka’s Java API… Reading through the API javadocs, it appears that the way to do so is to use this constructor: but I’m stuck as to what I should pass into the attributeValues parameter… when I put in null, Java complains about pr…
What is the most recommended way to store time in PostgreSQL using Java?
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…
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 🙂