Is it possible to iterate an Enumeration by using Lambda Expression? What will be the Lambda representation of the following code snippet: I didn’t find any stream within it. Answer In case you don’t like the fact that Collections.list(Enumeration) copies the entire contents into a (temporary) list befo…
Tag: java
What is difference between Collection.stream().forEach() and Collection.forEach()?
I understand that with .stream(), I can use chain operations like .filter() or use parallel stream. But what is difference between them if I need to execute small operations (for example, printing the elements of the list)? Answer For simple cases such as the one illustrated, they are mostly the same. However…
How do I tell Spring Boot which main class to use for the executable jar?
My project has more than one class with a main method. How do I tell the Spring Boot Maven plugin which of the classes it should use as the main class? Answer Add your start class in your pom: or
ANDROID: Converting inputted numbers to words
Our assignment states that we write a program that will input a number up to 6 digits and will convert the numbers into words.. ex: 123 = one hundred twenty three. I AM CLUELESS! Then I found this site http://www.rgagnon.com/javadetails/java-0426.html but I don’t really understand how to convert it into…
nested for loop for alphabet increment
I have searched everywhere and I cannot figure out how to create this output using a nested for loop in java: “a ab abc abcd” continued until z this is what I have tried String alphabet = “abcdefghijklmnopqrstuvwxyz”; Please help me! Answer Here is the answer: The outer loop switches f…
Java 8’s streams: why parallel stream is slower?
I am playing with Java 8’s streams and cannot understand the performance results I am getting. I have 2 core CPU (Intel i73520M), Windows 8 x64, and 64-bit Java 8 update 5. I am doing simple map over …
Boolean flags aren’t corresponding to the switch they are in
I’m trying to make a traffic simulator and I completely underestimated how hard it was going to be to get all the classes to work together. I’ve finally gotten all the functions to work quite well, and am now I’m trying to put them together. On my lights algorithm I’ve gotten the light…
Java APNS Certificate Error with “DerInputStream.getLength(): lengthTag=109, too big.”
When I try to using java APNS to send the push notification to iOS, I got this error message: com.notnoop.exceptions.InvalidSSLConfig: java.io.IOException: DerInputStream.getLength(): lengthTag=109, too big. I already try converting the certificate to Personal Information Exchange (.p12) also getting the same…
Why we shouldn’t make a Spring MVC controller @Transactional?
There are already a few questions about the topic, but no response at all really provides arguments in order to explain why we shouldn’t make a Spring MVC controller Transactional. See: Transaction not working correctly – Spring/MyBatis For web MVC Spring app should @Transactional go on controller…
How to get s:radio with label content as empty
I am using the struts tag s:radio as below; That is generating the HTML output as below; However I don’t want the label content like Yes or No. I am loading an image instead of that. How can I make that label content as blank or null? Answer Use a map to populate a radio tag. The value of the