What is a class without methods called? I’m trying to understand and learn about classes, so i have the following class “Variables” that doesn’t have methods, only fields, like the field “Server” in a folder called “utilities”: then this class is called from a m…
Tag: java
Zookeeper error: Cannot open channel to X at election address
I have installed zookeeper in 3 different aws servers. The following is the configuration in all the servers All the three instance have a myid file at var/zookeeper with appropriate id in it. All the three servers have all ports open from the aws console. But when I run the zookeeper server, I get the follow…
Spring batch FileItemWriter not creating file at correct path
I have a spring batch service containing a FileItemReader,FileItemProcessor and FileItemWriter.When creating the FileItemWriter I have to set the Resource that will be my output file. I am running the batch service on websphere on a Linux machine.The problem is if I set the resource as new FileSystemResource(…
java.nio.file.NoSuchFileException: why nio not creating file [closed]
Closed. This question needs debugging details. It is not currently accepting answers. Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question. Closed 7 years ago. Improve this question I am …
Referencing from an inner class
I have the following code My aim here is to create an array of JTextFields which have a keylistener on. This keylistener should prevent anything other than numbers being entered in the JTextField. It should also change the color of the JTextField’s background if the number entered is not an int. For exa…
How to implemet singleThreaded=true in TestNG
In TestNG i am trying to undertand the use of singleThreaded=true attibute of @Test Annotation .I already referred http://testng.org/doc/documentation-main.html and http://beust.com/weblog2/archives/000407.html but didn’t got much help . My Question : Why do we need to execute method on single thread. R…
Spark read file from S3 using sc.textFile (“s3n://…)
Trying to read a file located in S3 using spark-shell: The IOException: No FileSystem for scheme: s3n error occurred with: Spark 1.31 or 1.40 on dev machine (no Hadoop libs) Running from the Hortonworks Sandbox HDP v2.2.4 (Hadoop 2.60) which integrates Spark 1.2.1 out of the box Using s3:// or s3n:// scheme W…
How to extract the relative url from the absolute url in Java
I have this website: and I want to extract the relative part out of it: How do I do that? EDIT: I was offered an answer to a question, but the problem there was to build the absolute url out of the relative which is not what I’m interested in. Answer You could use the getPath() method of the URL
Repository Pattern with Repository Factory
I’m trying to improve my Android persistence layer to be used across multiple applications. What i have done so far is to setup a base repository abstract class and also a base repository interface, the complete code can be check here: https://github.com/grmaciel/android-repository-ormlite Interface: No…
Java infinite loop performance
I have a Thread that only has to work when a certain circumstance comes in. Otherwise it just iterates over an empty infinite loop: Does it affect the performance when the loop actually does nothing but it has to check if it has to do the calculation every iteration? Only creating a this Thread when needed is…