The new version of firefox is released, time to get a look at the plugins I have installed and maybe some nice ones to (re)discover.

delicious - If you do not know del.icio.us for storing your bookmarks yet, then you do not need this plugin. I suggest you do have a look at del.icio.us and start using it, since it is very easy and handy if you use a lot of computers.
linkedin - Handy if you are using Linkedin for managing your contacts and expending your network.
paypall - Using paypall made easy.
sage - This is an easy to use rss reader for firefox, I like it better than using thunderbird since firefox is available on almost all the pc's I use. Still figuring out if this is the best.
adsense - This plugin is handy if you have an adsense account. Show your earnings from the status bar.
pdf download - lets you choose whether to download or open the pdf file.
ie view - Open the current page in internet explorer if you really have to.

These are all fine plugins that I use on a daily basis. If you don't agree, have another or better one, let me know via the comments.

A few weeks a go I started using google analytics. What a cool tool. You can gather a lot of information about the usage of your website. Some very nice graphs are produced as well. Have a look at their website for more info. At the moment you cannot start using your own statistics. There were to many request, so they had to stop new requests from coming in for a while. Some of the statistics for my website.

Browsers used : Firefox 57%, ie 37%, Safari 4%, Opera 4%
Platform : windows 85%, linux 12%
Screen resolution : 1024x768 34%, 1280x1024 33%

Other interesting information is that most people find my website via google, some of the words most people search for are :
acegi
spring
ajax

Other good referers are the forum of springframework and the websites of the products that I use:
Serendipity, Pmwiki, and MiniBB

Most of you reed the blog, I guess this information changes the most. Reminds me that I want to start using the wiki for more thorough articles. But time is also limited for me . If people drill down into a blog subject, most of the time it is the item about ajaxtags. Other articles you are interested in are : hsql and java and rss and rome with spring

Interesting stuff, Google analytics, next time I will show you some of the graphs.

For a customer of mine I had another fine problem to resolve. He must send an email with a csv file as an attachment to his transport partner. The content for the csv file come from the database. Creating a string that has the contents for the file is easy, it would also be fairly easy to create a file, store it on the file system and add the file as an attachment. There is however one problem; I do not need the file after it has been attached to the email and send.

I started lookin at the api's of springframework related to email. It is not that hard to find some code that looks like the following to create the email to be sent:

1. MimeMessage message = getJavaMailSender().createMimeMessage();
2. MimeMessageHelper helper = new MimeMessageHelper(message,true);
3. helper.setFrom("from@gridshore.nl");
4. helper.setTo("to@gridshore.nl");
5. helper.setText("Text of the email");
6. helper.setSubject("attachment mail sample");

Now for the fun part, how can we attach a generated csv file to the email without storing it on th efile system first.

7. InputStream attach = new ByteArrayInputStream(mailMessage.getBytes());
8. StreamAttachmentDataSource datasource = new StreamAttachmentDataSource(attach,"attachment", "txt/plain");
9. helper.addAttachment(attachmentName,datasource);
10.getJavaMailSender().send(message);

The fun part is in line 8, you must create a custom implementation for the org.springframework.core.io.AbstractResource. This resource must convert an inputstream to an attachment. The code for this class looks like this:

public class StreamAttachmentDataSource extends AbstractResource {
  private final static Log logger = LogFactory.getLog(StreamAttachmentDataSource.class);
  private ByteArrayOutputStream outputStream;
  private String name;
  private String contentType;

  public StreamAttachmentDataSource(InputStream inputStream, String name,
  String contentType) {
  this.outputStream = new ByteArrayOutputStream();
  this.name = name;
  this.contentType = contentType;

  int read;
  byte[] buffer = new byte[256];
  try {
  while((read = inputStream.read(buffer)) != -1) {
  getOutputStream().write(buffer, 0, read);
  }
  } catch (IOException e) {
  logger.error("Cannot create inputstream for mail attachment");
  throw new AddAttachmentMailException("error.technical.mail.attachment");
  }
  }

  public String getDescription() {
  return "Stream resource used for attachments";
  }

  public InputStream getInputStream() throws IOException {
  return new ByteArrayInputStream(this.outputStream.toByteArray());
  }

  public String getContentType() {
  return contentType;
  }

  public String getName() {
  return name;
  }

  public ByteArrayOutputStream getOutputStream() {
  return outputStream;
  }

}

The hard part is not in the code, it is in finding the right code . What makes this a spring sample? I did use a number of utility classes from spring:
MimeMessageHelper - helps you with creating the mail message, a lot of try catch blocks less than with the standard way.
AbstractResource - This is a convenience class for creating your custom resources
JavaMailSender - Used to send messages that cannot be send as a SimpleMailMessage, implementation of th MailSender interface.

Today I did an upgrade of acegi for my sample application. Ofcourse there are a lot of resources about upgrading. There is an entry on the homepage of acegi and the blog from Matt Raible. These are my findings.

I have a CustomJdbcDaoImpl class, I used to obtain the granted authorities with the following lines of code:

PersonDetails person = (PersonDetails) users.get(0);
List dbAuths = getAuthoritiesByUsernameMapping().execute(person.getUsername());
if (dbAuths.size() == 0) {
  throw new UsernameNotFoundException("User has no GrantedAuthority");
}
GrantedAuthority[] arrayAuths = {};
addCustomAuthorities(person.getUsername(), dbAuths);

There is however a problem with the method ' getAuthoritiesByUsernameMapping()', this does not exist anymore in the 0.9.0 acegi version.
To be continued

The following change is getting a secure context. With the new version we use the following code to obtain a secure context:
SecurityContextHolder.getContext()

There is an issue with the events as well, there are now two main events, one for authentication and one for authorization:

<bean id="authenticationLoggerListener" class="net.sf.acegisecurity.event.authentication.LoggerListener"/>
<bean id="authorizationLoggerListener" class="net.sf.acegisecurity.event.authorization.LoggerListener"/>

I also had to change my SecurityEventListener, the names of the events are changed, the code now looks like this:
public void onApplicationEvent(ApplicationEvent event) {
  if (event instanceof AuthenticationFailureBadCredentialsEvent) {
  AuthenticationFailureBadCredentialsEvent authEvent = (AuthenticationFailureBadCredentialsEvent) event;
  securityManager.disablePerson(((User)authEvent.getAuthentication().getPrincipal()).getUsername());
  }
  if (event instanceof AuthenticationSuccessEvent) {
  AuthenticationSuccessEvent authEvent = (AuthenticationSuccessEvent) event;
  securityManager.savePersonLastLoggedOn(((User)authEvent.getAuthentication().getPrincipal()).getUsername());
  }
}

And finally, since my tag for authentication is now within the project I removed all the customized code for my custom taglibrary. See earliar posts if you want to know what I am talking about.

Today I created a nice autocomplete box with ajax and springframework. In my backoffice application I want to be able to select a product for an orderline. The moment I start typing valid options should be retreived from the database. Since I am creating a spring mvc application, so the ajax stuff must be incorporated into the spring application.

What did I use?

I used the ajaxtag project libraries and spring framework to do the ajax stuff. There are a few things to do, I am not going to give a lot of detais, have a look at the samples for a more thorough sample.

jsp to show form


1. <input type="text"
2. name="neworderlineproductshortcode"
3. id="neworderlineproductshortcode"
4. value=""
5. size="10"
6. class="form-autocomplete"
7. onkeypress="if (event.keyCode==13) return false;"/>
8. <input type="text"
9. name="neworderlineproductshortcodename"
10. id="neworderlineproductshortcodename"
11. value=""
12. size="40"
13. readonly="readonly"
14. class="readonly"/>
15.
16.<ajax:autocomplete
17. source="neworderlineproductshortcode"
18. target="neworderlineproductshortcodename"
19. baseUrl="${ctx}/autocompleteProduct.html"
20. className="autocomplete"
21. parameters="neworderlineproductshortcode={neworderlineproductshortcode}"
22. progressStyle="throbbing"
23. minimumCharacters="1" />

The code is just like the example, do have a look at line 7, this is a work around to make the enter key work. Actually this is all there is to it to make the ajax part work at the client. Pretty cool stuff. This image shows the webpage this autocomplete is on.

Where does spring come in?

From the line number 19 in the previous code sample we can see that the view 'autocompleteProduct.html' is used to get the ajax popup. We use an abstract controller that gathers the products from the service layer. Then it returns a ModelAndView to the following class:

1. package nl.primatras.backoffice.web.view;
2.
3. import java.util.List;
4. import java.util.Map;
5.
6. import javax.servlet.ServletOutputStream;
7. import javax.servlet.http.HttpServletRequest;
8. import javax.servlet.http.HttpServletResponse;
9.
10.import nl.primatras.backoffice.domain.Product;
11.
12.import org.ajaxtags.helpers.AjaxXmlBuilder;
13.import org.springframework.web.servlet.view.AbstractView;
14.
15.public class AutocompleteProductsView extends AbstractView {
16.
17. protected void renderMergedOutputModel(Map model,
18. HttpServletRequest request, HttpServletResponse response)
19. throws Exception {
20. response.setContentType("text/xml");
21. response.setHeader("Cache-Control", "no-cache");
22.
23. List products = (List)model.get("products");
24.
25. String xml = new AjaxXmlBuilder().addItems(products,"shortCode","name").toString();
26.
27. ServletOutputStream out = response.getOutputStream();
28. out.print(xml);
29. out.close();
30. }
31.
32.}

Interesting lines in this source code are:

• 20, ajax wants to have xml content to do his thing, so set the content type for the response.


• 25, create an xml string with the help of the AjaxXmlBuilder utility class.

Actually that is all there is to it.

It just hurts to put an article about ajax on my website, those knowing soccer teams in the netherlands will understand me. But nevertheless, I started reading this book mentioned above Foundations of Ajax. I have read the book and it has a high been there done that feeling. This has nothing to do with the book but more with my knowledge of Javascript and the DOM. About 2 years a go I did a lot with javascript and now this knowledge comes in hand. I think this is a nice book. I did not read anything about ajax until today, still the book is very easy to read (Mayby a little bit to easy if you have some prior experience). I do like the samples that are given, almost all classes and scripts are given in total and therefore easy to read and follow. A lot of screendumps clarify the examples. i gues the most interesting stuff is yet to come (the different toolboxes and unit testing your scripts). I also like the part where test driven Javascript development is discussed. The best part is chapter 8, a discussion of a more thorough example. A framework called Taconite is used to create a dashbord application. An example of using rss, word completion and using a webservice. The example can be easily deployed in a webserver.

I do have a note of critique, I think there is actually little theory in the book. I really read it in one week-end, so i guess it will take you about 8 hours fulltime. On the other hand that can be an advantage to

The book triggers me to find nice extensions for my websites, I cannot wait to try out some stuff in the book. I see this as a compliment. Well in short, I like the book and if you are clean in the area of ajax and want to learn something about it in a week-end, this is your book.

Within the next few weeks i will try some of the existing frameworks, I did have a short look at the demo from Matt Raible:
Matt Raible ~ Equinox and ajax