Spring Test DBUnit - Table already exists

by GarciaPL on Saturday, 16 April 2016

I had a chance to work with Spring Test DBUnit [1] (integration between Spring testing framework and DBUnit) with few tests related with Spring Integration. Most of them use the same common text context which contains embedded database H2. Funny thing was that some tests failed, because of some tables already exist. The issue is that embedded database is not cleared between tests and it is reused within the same context. That's why you should use @DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS) with @TestExecutionListeners({DependencyInjectionTestExecutionListener.class, DirtiesContextTestExecutionListener.class}) like below :

@TestExecutionListeners({DependencyInjectionTestExecutionListener.class, DirtiesContextTestExecutionListener.class})
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS)
public class YourTest {


Reference :
[1] Spring Test DBUnit

[2] Spring Framework - DirtiesContext


by GarciaPL on Thursday, 31 March 2016

I would like to announce that new Android app has been released recently times by me. This time application is called PerlJobs. This application helps you as a Perl developer to find new job opportunities across the globe. Job offers are divided into sections : Standard, Mod, Catalyst, Mason, Telecommute and By Country. The main source of all jobs is website : https://jobs.perl.org

Google Play Developer Page

by GarciaPL on Sunday, 6 March 2016

Yes! I finally managed to create it. Obviously it is not so pretty as it might be, but.. never mind :) If you would like to create your own Google Play Developer Page where you can add some promotion text and graphics (icon and background), just go to your Developer Console and then click Settings and then Developer Page. If you are looking for let's say 'inspiration', you can have a look on my Developer Page which link you can find below :

Pack CSV files in ZIP Archive

by GarciaPL on Saturday, 5 March 2016

This time I would like to share with small snippet of code written in Java and Spring MVC which might allow you to pack and download some files (in this case .csv file) in ZIP archive. So, if you will hit URL http://localhost:8090/yourApp/download/zip, Zip archive will be downloaded with name 'download.zip'.

    @RequestMapping(value = {"/download/zip"}, method = RequestMethod.GET)
    public void downloadZipArchive(HttpServletResponse response) throws IOException {

        List<MyClass> list; //should contains some records!
        if (list != null && !list.isEmpty()) {
            if (list.size() > 200000) {

                response.addHeader("Content-Disposition", "attachment; filename=\"download.zip\"");
                response.addHeader("Content-Transfer-Encoding", "binary");

                OutputStream servletOutputStream = response.getOutputStream();
                ZipOutputStream zos = new ZipOutputStream(servletOutputStream);

                int counter = 0;
                List<List<MyClass>> dividedlist = Lists.partition(list, 200000);
                for (List<MyClass> partition : dividedlist) {
                    zos.putNextEntry(new ZipEntry("file_" + counter + ".csv"));
                    CSVWriter writer = new CSVWriter(new OutputStreamWriter(zos));
                    writer.writeNext(new String[]{"HEADER"});
                    for (MyClass item : partition) {
                        writer.writeNext(new String[]{item.getText()});

Guava FluentIterable - Get only first object or null from list

by GarciaPL on Tuesday, 23 February 2016

A few days ago I had issue, that I need to get first object from some list which meet my requirements. Of course I can create some loop, write some if statement. If I will find interesting me object, then I am gonna return it. If I will not find any useful in whole list, then I am will return null.

Above solution is done in quite old-style approach. Now it is time for functional programming! I found very useful a library called Guava and it's utility class called FluentIterable. It supports you to manipulate Iterable instances in a chained fashion. This class has a lot of functionalities, but I would like to focus only on one case - get first interesting object to my pattern or just return null.

MyClass interestingObjectOrNull = FluentIterable.from(myList)
    .firstMatch(new Predicate<MyClass>() {
      public boolean apply(MyClass element) {
        return element.getId == 125L

And that's it! Simple, isn't ? All you need to remember to check returned object if it is null or not. Of course you might write as much complex apply pattern as you like.
Reference :
[1] Stackoverflow - Get only element of a collection view with Guava, without exception when there are multiple elements
[2] Pastebin - Source code

GPG error: http://downloads.hipchat.com Public key is not available

by GarciaPL on Saturday, 6 February 2016

Recently I had an issue during installation of HipChat from Atlassian on my Ubuntu. I mean that installation went well, but I had issue with GPG keys which was :

"GPG error: http://downloads.hipchat.com stable InRelease: The following signatures couldn't be verified because the public key is not available"

So, I managed to find that WebUpd8Team provides tool called y-ppa-manager. All you have to do is install y-ppa-manager like below :

sudo add-apt-repository ppa:webupd8team/y-ppa-manager
sudo apt-get update
sudo apt-get install y-ppa-manager

and then launch this tool. Select "Advanced" and then "Try to import all missing GPG keys". This operation might take a one or two minutes, so be calm and wait for notification. After that you can run sudo apt-get update to refresh repositories.

Reference : [1] Y PPA Manager - WebUpd8Team