Java scratchpad / Snippet Runner

I quite often find myself wanting to write quick snippets of java. Similar to little bash scripts.

This usually means I have to:
– launch eclipse
– start a new project
– create a new class
– write public static void main
– try to remember why I started eclipse…..

Well no more. I decided we could do things better. I present:

JPadIt lets you run little snippets of java code and instantly see the result rendered (hopefully) beautifully as either html tables or in a console mode..

Let me know what you think? Do you find it useful? Can we make it better? Definitely!

Apologies but there’s lots of bugs and we need to improve result presentation)

Julia Programming Language

Recently I’ve been looking into Julia, below are my somewhat random jumbled thoughts so far. I’ve also put together a function listing for julia that should help beginners. I should mention upfront that I actually really like the idea of Julia and that it has a lot of promise.

1. The long time taken for packages/recompilation is annoying and it failed on me a few times.

2. It just annoys me that the index starts at 1 – different than most other languages.

3. One of the most successful modules in python is pandas. Why not take this further and make DataFrames a full part of julia i.e. Make nulls, dataframes and DataArray the builtin for all vectors. If julia is going to be for manipulating data, there are always going to be nulls. Why have the duplication between julia arrays and DataFrames, make them one and the same.

4.Has a number of builtin functions that duplicate functionality available in just as short a form:


fill(0.,3)
zeros(3)
ones(3)

They add little and pollute the global namespace. Ken Iverson gives a wonderful talk on reducing a language to the minimal core here:
https://www.youtube.com/watch?v=8kUQWuK1L4w

5. There are many small bugs, inconsistencies and irritations such as:

Should super()/subtypes error on anything? because it does.


julia> super(bb)
ERROR: MethodError: `super` has no method matching super(::Regex)
julia> subtypes(bb)
ERROR: MethodError: `subtypes` has no method matching subtypes(::Regex)
julia> super("2")
ERROR: MethodError: `super` has no method matching super(::ASCIIString)

cd silently fails and isn’t cross platform.


julia> cd("/temp/")
julia> homedir()
"C:\\Users\\DAVE"

It should at least throw an error. Even better would be if julia supported forward slashes regardless of platform. Ensuring julia scripts are cross platform.


run(pipe(`echo world` & `echo hello`, `sort`))

The run command is weird, not like other languages at all. It uses backtick to enclose the command, supposedly to allow easy copy pasting
but what’s the point of that when you cant use piping within a single command, so you will need to break out each command separately anyway. Rather than this string interpolation I could just have used join() myself and have less surprise. This interpolation will also possibly cause issues with user entered commands. (A bit more browsing reveals there is a significant number of people find this a more powerful technique)

Writing to a file isn’t visible. This is very non-intuitive:


julia> f = open("a.txt", "w")
IOStream(<file a.txt>)
julia> write(f, "hello!")
6
julia> readall(f)
""
julia> f = open("a.txt")
IOStream(<file a.txt>)
julia> readall(f)
"hello!"

If possible I’d prefer not to have to even specify “w”, rather when its used by a function,
depending if its read or write, those functions handle the underlying details.

Best Method of Creating Windows Installer for Java Programs.

Requirements

  • Installer that adds link to start menu and file associations to windows
  • Running program appears as an exe and has its’ own file name in windows task manager
  • Use the built in JRE where possible or ask user to download if not available (bundling considered too large)

The finished installer can be seen at http://www.timestored.com/qStudio/

Solution

The best solution I found was launch4j and innosetup

launch4j

Launch4j was the only wrapper I found that let me keep a jar and have multiple exe’s that pointed to the same jar. Allowing me to have two programs but not double the size. One config to keep in mind when doing this is to use the chdir option with . to ensure paths work out properly.

InnoSetup

the tricky part with inno setup was getting the file associations to work. Here’s what I used:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
 
[Icons]  
Name: "{group}\qStudio"; Filename: "{app}\qStudio.exe"
Name: "{group}\sqlDashboards"; Filename: "{app}\sqlDashboards.exe"
 
[Tasks]  
Name: qAssociation; Description: "Associate .q extension"; GroupDescription: File extensions:
Name: kAssociation; Description: "Associate .k extension"; GroupDescription: File extensions:
 
[Registry]
Root: HKCR; Subkey: ".q"; ValueType: string; ValueName: ""; ValueData: "qKDBsource"; Flags: uninsdeletevalue; Tasks: qAssociation 
Root: HKCR; Subkey: ".k"; ValueType: string; ValueName: ""; ValueData: "qKDBsource"; Flags: uninsdeletevalue; Tasks: kAssociation 
Root: HKCR; Subkey: "qKDBsource"; ValueType: string; ValueName: ""; ValueData: "q KDB source"; Flags: uninsdeletekey;
Root: HKCR; Subkey: "qKDBsource\DefaultIcon"; ValueType: string; ValueName: ""; ValueData: "{app}\QFILE.ICO"
Root: HKCR; Subkey: "qKDBsource\shell\open\command"; ValueType: string; ValueName: ""; ValueData: """{app}\qStudio.exe"" ""%1"""

Combining into an ANT script

You want to

  1. Compile your JAR
  2. Create exes for both programs that point to the jar
  3. Place the exe’s into an installer

Like so (you need to install inno setup):

1
2
3
4
5
6
7
 
<launch4j configFile="src/main/resources/launch4j-qstudio.xml" />
<launch4j configFile="src/main/resources/launch4j-sqldashboards.xml" />
 
<exec dir="." executable="${INNO.SETUP.DIR}">
	<arg line="/cc '${basedir}\src\main\resources\windowsInstall.iss'" />
</exec >

Finished Installer

Can be found at http://www.timestored.com/qStudio/

 

Setup java speech jsapi using FreeTTS

Getting JSAPI setup to work using freetts seems to be quite difficult as seen by here, here, here…..

Turns out the install instructions were incomplete. The instructions were:

1. Go to the FreeTTS/lib directory
2. Type .\jsapi.exe
3. If the binary license agreement is acceptable, accept
it by clicking “I Agree”. The jsapi.jar file will be unpacked
and deposited into the lib directory.

What you actually want to do is:

  1. Download FreeTTS
  2. Unzip the freeTTS binary package and check inside the \lib directory for jsapi.exe
  3. Run Jsapi.exe, say yes, to unpack jsapi.jar
  4. Find your JRE directory, mine was C:\Program Files\Java\jdk1.6.0_03\jre\lib\ext
  5. Copy all the Jars (jsapi.jar, freetts.jar, cmu_time_awb.jar, cmu_us_kal.jar, etc.) to that directory
  6. Check in netbeans your projects properties ie right click on project->properties->libraries->manage platforms and the jars should be listed there. If they are not, restart and hopefully they should now be there.
    Netbeans Freetts Setup
  7. Copy speech.properties to the relevant folder. To find out where this is run the HelloWorld example that comes with FreeTTS. In my case the file was located in C:\Documents and Settings\Username\java.home\lib and contained the following
    1
    2
    3
    4
    5
    
    # Modify this accordingly...
    #
    #TextSynthEngineCentral=com.sun.speech.engine.synthesis.text.TextEngineCentral
    #
    FreeTTSSynthEngineCentral=com.sun.speech.freetts.jsapi.FreeTTSEngineCentral

    Or you can set the property using

    1
    
    System.setProperty("freetts.voices", "com.sun.speech.freetts.en.us.cmu_us_kal.KevinVoiceDirectory");

Any problems, post here and I will try to help you out.

Symfony sfGuard – Setting up users,groups,permissions

sfGuard is a Symfony plugin that implements a user management and login system for an application. It supports both groups and individual users… and it saves you from having to ‘roll your own’ user administration system. This guide assumes you have followed the steps given in the readme and that you now want to begin setting up users/permissions etc.

1. Create links in the backend menu to the user/group/permissions tables.

Edit apps/backend/templates/layout.php and add these items to the menu.

1
2
3
<li><?php echo link_to('Users', '@sf_guard_user') ?></li>
<li><?php echo link_to('Groups', '@sf_guard_group') ?></li>
<li><?php echo link_to('Permissions', '@sf_guard_permission') ?></li>

2. Create a login/logout link on the frontend.

Edit apps/frontend/templates/layout.php and add these items to the menu. (Notice the use of $sf_user in the templates.)

1
2
3
4
5
<?php if($sf_user->isAuthenticated()): ?>
   <ul><li><?php echo link_to('Logout', '/logout') ?></li></ul>
<?php else: ?>
   <ul><li><?php echo link_to('Login', '/login') ?></li></ul>
<?php endif; ?>

3. Create some users, groups, permissions

for us to play with using the backend. Create user->basicUser, group->basicGroup, permission->basicPermission. I will be using a basic setup where users always belong to a group and the group has permissions. I will not assigning permissions to individual users. therefore give basicGroup the basicPermission. and you will have something similar to this:

sfGuard user

4. Restricting access to certain modules/actions

Similar to how I never set individual permissions for one user I make it standard that I only ever set permissions using credentials. ie. In the application I never restrict security dependent on user or group id only on permission/credentials. This allows greater flexibility in the future. Note sfGuard gets confusing to some people because many documents talk about credentials, well basically credentials are what is called in sfGuard permissions.

If we have a module called “question”, inside of apps/frontend/modules/question we create a config folder and a new security.yml. Inside of apps/frontend/modules/question/config/security.yml we would have

1
2
3
all:
    is_secure: on
    credentials: basicPermission

To set permissions on an action level we would have something similar to the following:

1
2
3
4
5
6
7
8
9
10
all:
    is_secure: on
    credentials: basicPermission
 
index:
    is_secure: off
 
new:
    is_secure: on
    credentials: basicPermission

Part 2 will detail setting up user registration

Past Websites I Worked On

Some of the sites I have worked on are shown below:

mylanguagepal-247x300

MyLanguagePal.com – Online Language Swap

As part of a university project we created a website for users to exchange language skills. eg. A french person practises their english skills with an english person and vice versa. A number of new tools/challenges were faced. It was interesting to learn a PHP framework (symfony) that gave MVC separation. Working as a group meant my first real use of SVN. At last count the site had 267 registered users, WOOhoo!

2-similar-sao-300x230

Hong Kong – Student Affairs Office

While on IAESTE placement in Hong Kong for 3 months one of my tasks was a design overhaul of the student affairs office website and to use a CMS as the secretaries couldn’t edit HTML.

bbwinet-home-300x219

BBWI.net – small ISP

They requested a small “homely” design for their residential ISP. In the end they went with a more corporate professional design.

bknowledgeablecom-253x300

bKnowledgeable.com – Internet Startup

A website for those who seek knowledge. I never really understood the idea, but they knew the kind of design they wanted. Very little design work involved, was just a case of creating the HTML/CSS.

englishtalkonlinecom-256x300

EnglishTalkOnline.com – University Project

As part of an entrepreneurial project we required a quick website to offer language tutoring. Lets just say we never made it rich.

alta-300x171

ALTA – Adaptive Learning, Teaching and Assessment

I worked at ALTA professionally for a year. They had an entirely custom written piece of software that they saw as the future of testing children. It had some very interesting ideas, test questions vary slightly to prevent cheating, tests adapt to how well a pupil is doing etc. I got a lot of experience of MS-SQL and ASP programming, including bug finding. The picture shown here is the “messaging” system I created to allow teachers to message pup