Lost in heapspace

Android emulator too small for your app?

2011-12-19T03:45:00.000+01:00

Sometimes when you are developing Android applications they contains so much content it can be hard to test and verify on a Android emulator.

One way of allowing for larger applications is to use a API level 8 (or later) avd with an SD-card.
I have looked for a solution on the problem and got informed yesterday on how to do this.
It is fairly easy when you know what to do and most things are once you know what to do. :)

I work in a Linux environment so this might look different on your computer.
The trick is to find the configuration file for your avd and modify that a little bit.
I have chosen one of my avd:s the reside in my home folder:
~/.android/avd/norm_hdpi.avd

In that folder you can see a file named config.ini, open that file in a text editor and see if you can find a line starting with disk.dataPartition.size.
If it's there you can edit the number to suite you needs (it's in MB as far as I know).
Add it if you can't find it, I've been using lately (a bit of an overkill).
disk.dataPartition.size=150

Two one-liners to copy and rename files. :)

2011-12-19T03:33:00.000+01:00

Find all files with a specific name and copy to another folder:
find ./ -name "*stringtosearchfor*" -print | xargs cp -vt /home/folder/for/user/

Rename files by listing them and replacing unwanted characters and moving them to the new file name:
for i in `ls`; do mv "$i" `echo $i| sed s/stringtoreplace/withthisstring/g`; done

These commands have been tested on Ubuntu 10.10 and MacOS X

Problem updating Android apps on SD-card

2011-07-07T15:20:00.000+02:00

I have had problems updating applications on my SD-card in the phone.
Since I am a Android developer I could see the logs and the error I got was:

ASEC file '/mnt/secure/asec/smdl2tmp1.asec' currently exists - destroy it first!

I tried a lot of different things.
I tried to erase the file through eclipse, I tried installing the terminal emulator and those also failed.

I was about to remove the SD-card, buy an adapter and remove it manually when I read that people had mounted the phone on their computer.

What I did was that I connected the phone (HTC Desire with 2.2) to my computer (laptop running Ubuntu 11.04) and set the connection mode to HTC sync (there is probably matching modes for non-HTC phones).
When the phone has been mounted I got a popup asking what I wanted to do with the newly mounted drive.
I opened the drive with the file browser, pressed ctrl-h (show hidden files) and then I deleted the file in question.
The tricky part was that the file did not reside in the folder mentioned but rather in the folder

.android_secure

When I deleted the file everything worked as expected, I could even install our application that is configured with

android:installLocation="preferExternal"

How to send emails in Android

2011-06-28T09:46:00.002+02:00

I am new to Android development but I have done a few things and I found one thing really hard.
That this is filtering actions on the intent ACTION_SEND.

I have been trying to find much information (I have done no formal studying though but I am planning to do self studies this summer.

If you want to send emails the trick is in setting the the type of message to message/rfc822, rfc822 is an old RFC for text messages on ARPA net (http://www.w3.org/Protocols/rfc822/)

This is a code example that you look at to see how I did it (I have modified the code for readbility).

Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
String recipient = "some.email@email.com";
String body = "Hello, this is an email sent from an android phone";
String subject = "An Android program sent email";
String[] recipients = new String[]{recipient};
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, recipients);
emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, subject);
emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, body);
emailIntent.setType("message/rfc822");
startActivity(Intent.createChooser(emailIntent, "Choose email client");

SOAP Action and header authentication with Spring web services 1.5.9

2010-12-10T02:22:00.007+01:00

This is something I discovered yesterday.

We are currently using Spring-WS 1.5.9 and we're using a SOAP API that filters SOAP messages on the action sent in the SOAP header.

We are injecting the properties into our SOAP Client with Spring.

Earlier (I think) one could set it directly by doing like this:

I couldn't get this to work in 1.5.9.
What I did was to implement a WebServiceMessageCallback class that would do it for me.
I also implement SOAP Header authentication in it since the partner we are working with requires it.

public class MyWebServiceMessageCallBack implements WebServiceMessageCallback {
    private static final Logger LOG = LoggerFactory.getLogger(MyWebServiceMessageCallBack.class);

    private WSAuthenticateDocument wsAuthenticateDocument;
    private String soapAction;

    @Override
    public void doWithMessage(WebServiceMessage
                                      message) throws TransformerException {
        SoapMessage soapMessage = (SoapMessage) message;
        soapMessage.setSoapAction(soapAction);
        SoapHeader header = soapMessage.getSoapHeader();
        StringSource headerSource = new StringSource(wsAuthenticateDocument.toString());
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.transform(headerSource, header.getResult());
    }

    public void setWsAuthenticateDocument(WSAuthenticateDocument wsAuthenticateDocument) {
        this.wsAuthenticateDocument = wsAuthenticateDocument;
    }

    public void setSoapAction(String soapAction) {
        this.soapAction = soapAction;
    }
}

It's been quiet for a while.

2010-12-05T05:23:00.000+01:00

This is mainly because I have been working as a scrum master and been very busy at my previous employer.

I have now moved to Cambodia to work as a developer which is kind of interesting.
The current technologies I am working with is Spring, Web services and google app-engine.

I hope I will learn something that is worth posting on the blog.

/Marco

Compiling google protocol buffer files from Maven2

2010-06-28T21:06:00.011+02:00

This example is a bit outdated since it is using the sourceRoot tag in the AntRunner plugin but this is a working example.
The only drawback is that I have to have all .proto files in the same directory.

I haven't had the energy to continue to set this up with a **/*.proto style filter since the exec tag does not support file sets as far as I remember.

Handling error codes from Maven during the build process

2009-05-28T10:49:00.002+02:00

If you are using a batch script to build out project and some other way to deploy it (ant) you need to stop the batch file from executing when the maven command has failed.

I did it this way:

@echo off
call mvn clean install
IF ERRORLEVEL   1 GOTO :end

call scriptThatShouldBeCalledUponFailure

:end

Encoding warning when building with maven

2009-05-28T10:39:00.003+02:00

If you get a warning saying the following:
[WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!
you need to add a property to the root pom of you project, the property is named
project.build.sourceEncoding and the tag should be placed like this.

<project>
...
<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
...
</project>

Just be sure to save your files in the specified encoding to avoid encoding problems.

How to open spotify URI:s from a webpage with Firefox

2009-02-19T16:27:00.010+01:00

This small guide is created for the windows users out there. :)

Start by creating a script in a suitable location, in this tutorial I use C:\scripts.
Create the folder if it does not exist and create a file named browser2spotify.cmd within that folder.
Edit the file in a text editor and add the following line into it:
"C:\Program Files\Spotify\spotify.exe" /uri "$@".
NOTE!: The install location is for an installation on the english version of windows, your might look different.

Enter about:config in the address-bar Click ok in the warning

Right-click in the table shown and choose to add "New > Boolean"
Give it the name network.protocol-handler.external.spotify and set the value to true

Right-click again to add another filed but this time choose "New > String" and enter network.protocol-handler.app.spotify as key and C:\scripts\browser2spotify.cmd as value.

This should be all and when it is done you can try and click on this link to test your settings.

If you still can't open the link, please check the spotify help for information

Tabbing between panels in GWT

2009-01-30T16:05:00.013+01:00

When you are creating panels and add widgets with natural tab order everything is fine as long as you are within a single panel.

I solved the multi-panel tabbing with natural tab order by fetching the first component from the other panel and setting focus to it.

Here we fetch the widget (the method just returns a hard coded widget from the panel).


headerPanel.getFirstTabItem()

Here I extend the printbutton (it is the last button in the panel) and implements the


public class TabAwarePrintButton
    extends PrintButton
    implements SourcesKeyboardEvents {
   private FocusWidget nextFocusItem = null;

      public TabAwarePrintButton(final FocusWidget nextFocusItem) {
         super();

         this.nextFocusItem = nextFocusItem;

         sinkEvents(Event.ONKEYDOWN);
      }

      public void onBrowserEvent(Event event) {
         switch (DOM.eventGetType(event)) {
         case Event.ONKEYDOWN:

            if (event.getKeyCode() == '\t') {
               nextFocusItem.setFocus(true);
               DOM.eventPreventDefault(event);
            }
         break;
      }
   }
}

How to track your blog with google analytics

2008-12-17T12:38:00.008+01:00

I found a guide which explains how to add google analytics tracking of your blog.

I added the tracking code in the footer of my blog and to verify I entered "Analytics Settings > Profile Settings" to check the status of my analysis.
You can find the status link in the upper right corner of the "Main Website Profile Information"

There you should see information about your tracking status (don't forget to access your blog with at least one request to notify Google Analytics).

If you see anything else but "Waiting for data" you have done something wrong and should check that everything is done correctly.

Also check this google page to get more information in how to verify the setup.

JMeter latency explained

2008-12-17T10:45:00.004+01:00

When I started using JMeter and was wondering about the latency field which I think is not well explained in the documentation.

I tried searching the internet for an answer to the question and the closest I found was that latency is the time from just before sending the request until the request has been processed (request and reply assembly).
In short, this should be a more accurate time from a user experience view than the elapsed field which is the time from when the request is sent until a response is received.

See this Nabble mailing list entry for more information.

Optimize TortoiseSVN Cache (TSVNCache.exe) Disk I/O

2008-12-15T17:25:00.003+01:00

TSVNCache.exe is a process that handles the explorer icons as far as I have gathered, the process can hog a lot of disc I/O which is quite annoying.

I have found a solution to the problem and that is to disable icon overlays for all folders except the ones you really want overlaid. :)

Enter ToirtoiseSVN settings, choose Icon Overlays and in the bottom part of the applet you have two listboxes (Exclude paths and Include paths).

Enter the root folder of all drives in the Exclude paths and the enter the folders you want overlaid in the includes path according to the picture below.
The last thing you should do is to check the box that says "Show excluded folders as normal".

This should get you sorted. :)

Specifying repository directory for Maven2

2008-12-15T14:08:00.005+01:00

If you do not like the default location of the maven repository you can control this by creating a settings.xml file in your homedirectory/.m2

The contents of the settings.xml should be like the following example:

<?xml version="1.0" encoding="UTF-8"?>
<settings>
    <localrepository>/path/to/your/repository</localrepository>
</settings>

Specify DocumentBuilderFactory with multiple XML implementations

2008-12-02T16:52:00.009+01:00

I was using standard Java XML parsing and XPath when I started using JFreeChart which in turn uses the gnujaxp implementation.

This implementation broke my current implementation with the error-message:
java.lang.AbstractMethodError: gnu.xml.dom.DomElement.getTextContent()Ljava/lang/String;

I searched the internet but ended up looking in the API for leads on how to specify which implementation I would use for the DocumentBuilderFactory (DocumentBuilderFactory.newInstance();)

I quickly realized that if I set the environment variable javax.xml.parsers.DocumentBuilderFactory to com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl it would solve the problem.
I chose the xerces string from debugging and looking at the DocumentFactory instance. :D

This is an excerpt from the actual code.


System.setProperty("javax.xml.parsers.DocumentBuilderFactory", "com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl");
 DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();

Happy hacking to you all.

Problems with namespace in XPath (Java)

2008-11-18T13:47:00.027+01:00

I had some problems with namespaces and xpath queries.

The solution is to implement the javax.xml.namespace.NamespaceContext inteface with a class and implement the public String getNamespaceURI(String prefix) method.

in this method you can implement a if/else clause like this


public String getNamespaceURI(String prefix)
if (prefix.equals("mynamespace")) {
 uri = "http://xml.svtplay.se/ns/playrss";
} else {
 uri = null;
}

return uri;
}

MyNameSpaceContext ctx = new MyNameSpaceContext();

XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
xpath.setNamespaceContext(ctx);

Check out this blog entry in the blog of David Bergman (Davber) for more information.

What if you have attributes with a namespace?
Well, this I have found a solution to but I don't think it is the best solution (it's quite ugly and matches all attributes with the same name) but it works in my case. :D
example XML:


<root>
<node myNameSpaced:attribute="value" />
</root>

To make a xpath request work you need to call a function in the parser like this:


xpathExpression xpathExpression=
"//*/@*[local-name()='attribute']"
XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
xpath.setNamespaceContext(ctx);
XPathExpression expr = xpath.compile(xpathExpression);

Want to know what you site looks like in another environment?

2008-11-13T08:55:00.003+01:00

I have discovered a very nice site that lets you test your site in different browsers and operating systems.
Current "OS"s are Windows, Linux, MacOS, and BSD with many browsers on each platform.

Go check it out!

Browsershots

How to supress header in XSLT

2008-11-12T17:20:00.003+01:00

Add this line to your xsl if you want to omit the header

<xsl:output omit-xml-declaration="yes"/>

Tomcat and MC4J on windows

2008-11-07T15:41:00.003+01:00

Install Tomcat 5.5 (service installer)
install MC4J

Go to your jre 1.5 installation directory
Enter folder lib\management
copy jmxremote.password.template to jmxremote.password
Add and entry with username password last in the file
mc4j jmxuser
in the same folder you must edit the file management.properties
uncomment the line looking like this:
com.sun.management.jmxremote.authenticate=false

Edit the Tomcat service properties and add the following line
-Dcom.sun.management.jmxremote.port=8999

Start Tomcat (it should start)
Start MC4J
Start the server wizard by clicking the “Create Server Connection” button
Select Tomcat 5.5+ in “Connection type” dropdown box
Give the connection a name
Set “Principal” to mc4j
Set “Credentials” to jmxuser
Click next
Click add and browse to your tomcat installation directory (The valid server directory is in bold font)
Click “Select Server”
Click “Next”
Click “Finish”
MC4J should connect and you are now able to browse your Tomcat.

Installing Fedora9 on vmware for windows

2008-10-30T11:30:00.008+01:00

This is a short guide to installing Fedora9 on Vmware Server2 with a network install

First you need to download boot.iso from Fedora server
http://mirror.anl.gov/pub/fedora/linux/releases/9/Fedora/i386/os/images/boot.iso

Then you need to download vmware server2 from vmware
Create a virtual machine named Fedora9
Copy the downloaded boot.iso into virtual machine directory
C:\Virtual machines\Fedora9
Add hardware->CD/DVD->From ISO->browse to ISO
Boot the virtual machine and choose to install from network.
Add url ftp://alviss.et.tudelft.nl/pub/fedora/linux/releases/9/Fedora/i386/os/

Rock on!

Installing Fedora9 from USB-memory

2008-10-30T10:09:00.017+01:00

Download boot.iso from fedora server, I used Fedora9 and this URL:
http://mirror.anl.gov/pub/fedora/linux/releases/9/Fedora/i386/os/images/boot.iso

Install image on usb memory with dd
http://uranus.it.swin.edu.au/~jn/linux/rawwrite/

insert USB-memory stick (mine got mounted as f)
write image to USB with
dd --size if=c:\downloads\boot.iso of=\\.\f: --progress

I tried with the filter (--filter=removable) which is really good if you are not very sure about what you are doing but it didn't match my drive.
When I did dd --list it was reported as
\\.\Volume{fec8f94c-a65d-11dd-af64-001aa0854e6c}\
link to \\?\Device\Harddisk2\DP(1)0-0+7
removeable media
Mounted on \\.\f:
The spelling of removable is different from that of the filter, could that be the problem?

Wait for the image to be written (this took 15 minutes when I did it)
This is what it looks like when it is finished:
rawwrite dd for windows version 0.5.
Written by John Newbigin
This program is covered by the GPL. See copying.txt for details
119,234,560
232880+0 records in
232880+0 records out

Configure BIOS to boot from the image and boot from the memory stick.
The machine should now boot from your image.

Making Foxmarks work with a proxy

2008-10-29T19:41:00.001+01:00

I am using Foxmarks with my own server and in my current assignment I am behind aproxy server. Foxmarks does not work well with proxy servers so I had to find a solution to the problem.
After almost giving up I realized that since the proxy is the problem, why not remove it from the equation?
I put my server on the proxy exception list and voilá, it all worked!

In short, ä'¨¨¨¨¨gby7t4vfgftmnvb§§§§§§§§§§§§ (sorry about that people, one of the cats decided to take a walk across the keyboard) add your server to the proxy exceptions in network settings.