I am testing a helper class with only static methods with JUnit4 and Cobertura. Testing methods was easy task and is done already. However, cobertura shows that the class is not covered by tests completely, as it is not instantiated anywhere. I don’t want to create an instance of this class (it is a hel…
Tag: java
android – How to detect application being activated
When the app is launched, Application onCreate is called. How to detect when the app is brought to front from running in background? Answer Look for onResume() method. Its is always called when your app comes foreground. As per google docs: The foreground lifetime of an activity happens between a call to onRe…
why using volatile with synchronized block?
I saw some examples in java where they do synchronization on a block of code to change some variable while that variable was declared volatile originally .. I saw that in an example of singleton class where they declared the unique instance as volatile and they sychronized the block that initializes that inst…
How to understand whether it is going to exceed the Java Heap Size or not?
I implemented a program about calculating the stock values comparing that value in the given times’ values and etc.. I have a csv file which has all dates and double values. In my program for every single date, I’m openning a file, parsing and searching the value of the given date. And I may check…
Resolving javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed Error?
Edit : I tried to format the question and accepted answer in more presentable way at my blog. Here is the original issue. I am getting this error: detailed message sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find v…
Get domain name from given url
Given a URL, I want to extract domain name(It should not include ‘www’ part). Url can contain http/https. Here is the java code that I wrote. Though It seems to work fine, is there any better approach or are there some edge cases, that could fail. Input: http://google.com/blah Output: google.com A…
Working around the “variable might not have been initialized” error
If this isn’t possible, could you suggest a better way to do this? I couldn’t find a method for it in ScheduledThreadPoolExecutor. basically what I’m trying to do is make this code be run 3 times then cancel the “timer.” I could probably use Swing Timer, but I don’t want to…
Setting socket read timeout with javax.xml.soap.SOAPConnection
I am using the javax.xml.soap API (javax.xml.soap.SOAPConnectionFactory, javax.xml.soap.SOAPConnection, and friends) to make a web service call to a remote server, for the most part with great success. However, sometimes there is a problem and the program gets stuck reading forever. To address this, I’d…
Trouble understanding Java threads
I learned about multiprocessing from Python and I’m having a bit of trouble understanding Java’s approach. In Python, I can say I want a pool of 4 processes and then send a bunch of work to my program and it’ll work on 4 items at a time. I realized, with Java, I need to use threads to achiev…
What namespace does the JDK use to generate a UUID with nameUUIDFromBytes?
The Sun/Oracle JDK exposes a function to create a type 3 (name based) UUID in the java.util package: java.util.UUID.nameUUIDFromBytes(byte[] name). I need to be able to generate a type 3 UUID in Java using nameUUIDFromBytes and arrive at the same UUID when creating a type 3 UUID in another language, assuming …