Bill Comer's Blog

Multiple search windows in eclipse

2012-01-04T17:00:00.002Z

This is a really simple but cute little feature.

If you pin one search window using the pin icon at the right hand end of buttons then the next time you do a search eclipse will open up a new Search window.

There is also a search history that you can look through just to the left of the pin icon.

finding the correct spring jar for a known class

2011-09-23T14:54:00.000+01:00

With Spring 3 you now have to get all the individual jars that you need for an application.

One solution is obviously to download the lot.

But what if you just want to install what is needed.
How do you easily find which jar a class is in ?

Well I have just found this Spring Bundle Search tool.

You can enter just the class name or the class with its full package name.

windows7 Administrator mode from the command line

2011-08-31T09:41:00.002+01:00

Type 'cmd' in the Run window as normal but instead of simply hitting the return key, use Ctrl-Shift-Return

Auditing using AOP and annotations in Spring

2011-07-04T14:27:00.020+01:00

Lord, how I dislike the old XML configuration for AOP (among other things).

I have not given myself the opportunity to try out Spring's annotation based AOP in spring, until now and boy is it easy (with one minor gotcha).

Here are the building blocks:

1) Make your own Annotation. This is a simple way to mark all methods you want to audit.

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface ParmsAudit
{
  ActionAuditType  auditType();
}

2) ActionAuditType is an enum that will be used to identify the thing being audited.

public enum ActionAuditType {
USER_LOGGED_IN("User Logged In"),
USER_LOGGED_OUT("User Logged Out");

private String mDescription;
  private ActionAuditType(String aDescription) {
 mDescription = aDescription;
}


public String getDescription() {
 return mDescription;
}
public void setDescription(String aDescription) {
 mDescription = aDescription;
}
}

3) Create an Aspect. This is the code that is run when the method marked by the annotation is called.

Here is the minor gotcha - well for me atleast.

I had to list the full package path to the Annotation in the @Before statement.


@Aspect
public class AuditAspect {

@Before(value="execution(@uk.co.billcomer.audit.ParmsAudit * *(..)) &&   @annotation(parmsAudit)", argNames="parmsAudit")
public void logTheAuditActivity(JoinPoint aPoint, ParmsAudit parmsAudit) {
 String userName = getUserName();
 mlogger.info("Parms Auditing User Name: " + userName);
 mlogger.info("auditType:" + parmsAudit.auditType().getDescription());

 String arguments = getArgs(aPoint.getArgs());

 if (arguments.length() > 0) {
 mlogger.info("args-" + arguments);
 }
}

private String getArgs(Object[] args) {
 String arguments = "";
 int argCount = 0;

 for (Object object : args) {
   if (argCount > 0) {
     arguments += ", ";
   }
   arguments += "arg[" + ++argCount + "]=" + "[" + object + "]";
 }
 return arguments;
}

private String getUserName() {
 try {
   return SecurityContextHolder.getContext().getAuthentication().getName();
 } catch (NullPointerException npe) {
   return "Unknown User";
 }
}
}

4) Mark the method to be audited.


@Service("parms.DummyAuditThing")
public class DummyAuditThing implements DummyAudit {

@Override
@ParmsAudit(auditType = ActionAuditType.USER_LOGGED_IN)
public void aspectAuditMethodTwoParams(String param1, Long param2) {
 mlogger.info("In method to be audited param1[" + param1 + "], p2[" + param2 + "]");
}
}

5) Context configuration

This is needed to speed up the compilation process. Essentially it tells the compiler what classes will have Aspects

      <aop:aspectj-autoproxy proxy-target-class="true"/>   
   
   <bean class="org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator"/>
   <bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>
   
   <bean id="bill.auditAspect" class="uk.co.billcomer.audit.AuditAspect" />

android phone calendar not synching

2011-06-01T08:07:00.002+01:00

The other day the calendar on my android phone stopped synching correctly to my google calendars.

It was partly way there. It new about the calendars but would not display any of the data.

I found this which did not describe my solution 100% but put me on the right track.

Go to Settings->Applications->Manage Applications->Calendar and select 'Clear data'.

This will give you a pop up box saying all the applications data willbe deleted permanently. Do not worry & select the the 'OK'.

Now go back to your calendar app and you will find all your calendars restored.

unix WC command out by 1 - wtf

2011-05-26T14:44:00.003+01:00

I am develop on a windows PC (for my sins) but to keep me feeling secure I use cygwin (a unix shell for windows. Today this has done me in.

The application I am working has to create files and in the final line of the file it has to include the number of the lines in the file. All simple enough and it did exactly what it was supposed to do.

However when I came to check the results manually I used the unix 'wc' command and this gave me a row count 1 less than what I was expecting and what the footer said was in the file. Strange.

I edited the file with 'vim' and low & behold wc was incorrect - what is going on ?

I then edited the file with hexEdit and noticed there was no CR & LF on the last line. Adding these made wc give the correct count.

Logging bind variables with hibernate

2011-03-10T14:05:00.004Z

You could use something like p6spy as suggested by a friend of mine Andy, but I wanted something that was trivial to configure and potentially available to the live application and easy to set up.

After a bit of digging I found Sathya's blog with the solution I needed.

I already had the log4j jar.

What I was missing was the slf4j-log4j12 jar

and the following line in my log4j.properties

log4j.logger.org.hibernate.type=TRACE

FileUpload with multipart/form-data in Spring 2.5.x and Annotations

2011-02-24T09:48:00.005Z

Firstly a qualifier, This is for Spring 2.5.x with annotations.

I have not had the pleasure of upgrading to Spring 3.X yet.

There is some excellent documentation on File Upload with Spring.

However for an annotation driven Controller it misses out one important step, namely the @InitBinder annotation.

@InitBinder
public void initBinder(ServletRequestDataBinder aBinder) throws ServletException {
// to actually be able to convert Multipart instance to a String
// we have to register a custom editor
aBinder.registerCustomEditor(String.class, new StringMultipartFileEditor());
// now Spring knows how to handle multipart object and convert them
}

Chrome and Grouping/Organising tabs

2011-02-17T11:36:00.003Z

Do you find that you end up with loads of tabs open for several different subjects, and not wanting to close them......just yet.

Well today I found this chrome plugin for grouping tabs. It is something I have wanted for a while.

It is not quite as funky as Forefox's soon to be released Release 4 Tab Organising but it does the job nicely.

keepass on android

2010-12-21T07:58:00.004Z

I have just entered the 21st century phonewise and got an android phone, the motorola defy, and very pleased with it I am.

The first two apps I put on the phone are keepassdroid and dropbox.

I have blogged about these in the past and now I have my phone synced to the same keepass database. For all those i-phone users there is of course an i-phone version too. It all works a treat so I still do not need to know any of my passwords.

One slight issue I had, my PC version of keepass was out of date so I had to upgrade that to get the two keepass clients to work together.

eclipse, junit & static imports

2010-11-24T14:48:00.004Z

It was annoying me that eclipse was not finding the static imports needed by junit 4 unit tests.

A quick google tuned up this gem, which I have grabbed below:

Open the Preferences via Window -> Preferences and select Java > Editor > Content Assist > Favorites. Add then via "New Member" the methods you need. For example this makes the assertTrue, assertFalse and assertEquals method available.

You can now use Content Assist (Ctrl+Space) to add the method and the import.

He suggests to add at least the following new members.

org.junit.Assert.assertTrue
org.junit.Assert.assertFalse
org.junit.Assert.assertEquals
org.junit.Assert.fail

I suggest also adding

org.junit.Assert.assertNotNull

pidgin - Unable to validate certificate error

2010-11-19T08:30:00.002Z

If you are having the 'Unable to validate certificate' error from pidgin then do the following:

go to here, download the certificate omega.contacts.msn.com.pem
in pidgin go to tools/certificates
delete the cert omega.contacts.msn.com.pem
add the new downloaded cert
and away you go

UPDATE - or as I have said in the comment, now you can download the new version with a fix - see or better still update to the latest version that now has the fix - http://www.pidgin.im/

SQLdeveloper & showing the full date

2010-10-21T10:43:00.006+01:00

I keep getting this every time I install SQLDeveloper.

The date shown is just dd/mm/yyyy with no hours:minutes:seconds

The solution can be found here on Zenx's blog, but to save me looking here it is also.

1. From SQL Developer, open menu Tools >> Preferences.
2. From the Preferences dialog, select Database >> NLS Parameters from the left panel.
3. From the list of NLS parameters, enter DD-MON-RR HH24:MI:SS into the Date Format field.
4. Save and close the dialog, done!

Thanks Zenx.

Also, if you want milli-seconds add ':SSSSS' at the end.

git & github from windows

2010-10-20T10:15:00.005+01:00

While learning Grails and working though 'Grails in Action' I wanted to save my work to a repository. SVN can be a pain to setup on windows and many people use github & so I thought I would give it a go.

Sadly I am on a windows PC but I have just been so pleasantly surprised as to how easy it was.

This is what I had to do:

I work from a cygwin command shell. In this I had to have ssh & git executables installed.
help to set up the ssh key is here .
I did not realise that git acts as a local repository as well as a public repository so you are under no obligation to upload your work. The local set up is a breeze and is described in this excellent tutorial, running the commands from my cygwin shell.
There is even a GUI with the command 'gitk'
Once you want to upload the code to a public github repository it is a simple case of running the following two commands:

cd existing_git_repo
git remote add origin git@github.com:bill-comer/hubbub.git
git push origin master

And you can download code from github using the following:

git clone   git@github.com:bill-comer/hubbub.git

Now go ahead and enjoy a free and easy to use code repository.

Grails & 'Grails in Action' - some notes & comments

2010-09-30T09:36:00.021+01:00

I have just started playing with grails.

I am using 'Grails in Action' as my reference.

My current version of grails is 1.3.4

I am using the STS eclipse IDE with their built in grails plugin

Here are some initial notes on GOTCHAs I have found with the book and grails itself.

NB I will continue to update this one page with other gotchas, instaed of creating many pages.

Comments on 'Grails in Action'

1) p28, list 1.22

'render' should be 'response.outputStream <<'

2) logo.png & snazzy.css are needed for chapt 1 & can be got from github

Comments on Grails 1.3.4

1) can not create integration tests - getting error

Error executing script CreateIntegrationTest: No such property: type for class: CreateIntegrationTest

No such property: type for class: CreateIntegrationTest

edit the file scripts/CreateIntegrationTest.groovy in your grails installation

and add the line

def type = "Tests"

after the line

depends(checkVersion, parseArguments)

solution from http://jira.codehaus.org/browse/GRAILS-6606

NB this is fixed in 1.3.5

2) when running the test via 'grails test-app' the url for the report is incorrect

and is missing the trailing 's' from the URL

edit the file scripts/_GrailsTest.groovy line 402 and add a space after the the closing brace of testReportsDir and before the double quote

msg += " - view reports in ${testReportsDir} "

3) 1.3.5 bug - add a contraint that specifies the size of the field then it does not check for null.

IE This will allow a nulll value in name:

static constraints = {
   name (size:3..8)
 }

The work around is to do this:


static constraints = {
  name (size:3..8, blank:false)
}

bug GRAILS-6821 has been raised on version 1.3.5

keepass and dropbox combined.

2010-09-21T20:21:00.009+01:00

A while ago I blogged about using keepass as a secure password & data storage tool.

The blog entry is here.

The issue I have always had is keeping the keepass db in sync between my different PCs at work & at home and on the move. I used to use a memory stick but decided that was prone to getting lost or damaged.

I have recently started using dropbox. This tool provides online storage allowing sync between any number of devices and supports linux, i-phones, android, iPad as well as Microsoft platforms. It is free for the first 2GB and you get to earn additional storage by either nominating others or getting nominated by an existing member.

From the reviews I have read it appears secure so I have started using it for my keepass database as well as any every day stuff I want to share.

As for reviewing keepass I am still very pleased and impressed with it.

My family now all have their own keepass databases to keep their personal data.

So if you want to try dropbox, follow this referral link and try it out.

tomcat IE and parse locale Exceptions

2010-09-16T12:10:00.005+01:00

I have just done an upgrade for a customer that involved new java, tomcat as well as a new version of our application software.

The webapp was failing with the following Exception:

Caused by: javax.servlet.jsp.JspException: In &lt;parseNumber&gt;, a parse locale can not be established
 at org.apache.taglibs.standard.tag.common.fmt.ParseNumberSupport.doEndTag(ParseNumberSupport.java:134)
 at org.apache.jsp.tag.web.shared.paging_tag._jspx_meth_fmt_005fparseNumber_005f0(paging_tag.java:598)
 at org.apache.jsp.tag.web.shared.paging_tag.doTag(paging_tag.java:241)
 at org.apache.jsp.pages.jsp.type3Footer_jsp._jspx_meth_tag_005fpaging_005f0(type3Footer_jsp.java:220)
 at org.apache.jsp.pages.jsp.type3Footer_jsp._jspService(type3Footer_jsp.java:114)
 ... 73 more

Some googling pointed me to adding locale java options:

http://stackoverflow.com/questions/1153521/setting-default-locale-for-tomcat-service-in-windows-xp
java -Duser.language=en -Duser.region=GB

This just shifted the problem to Oracle Exceptions complaining about NLS_LANG and suggesting

that I do a regedit
http://www.dba-oracle.com/t_ora_12705_error.htm
That was a step too far

After all the application worked fine before.

So what was my final solution.

Very simple. In IE go to Tools->Internet Options->General/Languages.

found out there were no languages set
Add the appropriate one
English (United Kingdom) [en-gb] in my case.

IntelliJ Live Templates for Eclipse ...more

2010-08-20T10:02:00.003+01:00

This is an update from an earlier post of mine so save me following two links & then having to edit the file.

To Import them into eclipse go to Window -> Preferences -> Java -> Editor -> Templates and import away.

<?xml version="1.0" encoding="UTF-8" ?>
<templates>
<template autoinsert="true" context="java" deleted="false" description="iterate over array with temporary variable" enabled="true" name="itar">for (int ${index} = 0; ${index} &lt; ${array}.length; ${index}++) { ${array_type} ${array_element} = ${array}[${index}]; ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="iterate over collection" enabled="true" name="itco">for (Iterator ${iterator} = ${collection}.iterator(); ${iterator}.hasNext(); ) { ${type} ${element} = (${type}) ${iterator}.next(); ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="iterate with enumeration" enabled="true" name="iten">while (${enumeration}.hasMoreElements()) { ${type} ${element} = (${type}) ${enumeration}.nextElement(); ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="iterate over an array or Iterable" enabled="true" name="iter">for (${iterable_type} ${iterable_element} : ${iterable}) { ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="iterate with iterator" enabled="true" name="itit">while (${iterator}.hasNext()) { ${type} ${element} = (${type}) ${iterator}.next(); ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="iterate over list elements" enabled="true" name="itli">for (int ${i} = 0; ${i} &lt; ${list}.size(); i++) { ${type} ${element} = (${type}) ${list}.get(${i}); ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="public static final" enabled="true" name="psf">public static final ${} = ${cursor};</template>
<template autoinsert="true" context="java" deleted="false" description="public static final int" enabled="true" name="psfi">public static final int ${} = ${cursor};</template>
<template autoinsert="true" context="java" deleted="false" description="public static final String" enabled="true" name="psfs">public static final String ${} = ${cursor};</template>
<template autoinsert="true" context="java" deleted="false" description="main method" enabled="true" name="psvm">public static void main(String[] args) { ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="public void test" enabled="true" name="pvt">public void test${NAME}() throws Exception { ${cursor} }</template>
<template autoinsert="true" context="java" deleted="false" description="print to standard error" enabled="true" name="serr">System.err.println(${word_selection}${});${cursor}</template>
<template autoinsert="true" context="java" deleted="false" description="print to standard out" enabled="true" name="sout">System.out.println(${word_selection}${});${cursor}</template>
<template autoinsert="true" context="java" deleted="false" description="print method name to system out" enabled="true" name="soutm">System.out.println("${enclosing_type}.${enclosing_method}(${enclosing_method_arguments})"); ${cursor}</template>
<template autoinsert="true" context="java" deleted="false" description="print variable out to System out" enabled="true" name="soutv">System.out.println("${VALUE} = " + ${VALUE});</template>
<template autoinsert="true" context="java" deleted="false" description="public void test" enabled="true" name="test">public void test${NAME}() throws Exception { ${cursor} }</template>
</templates>

Getting eclipse to connect to a running tomcat

2010-07-05T14:49:00.002+01:00

Firstly tomcat needs to set up to allow a debug connection.

These instructions are for windows - sorry.

Go to the tomcat/bin directory and run tomcat6w.exe
Click on the java tab
To connect on port 8002 add the line:
-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8002
And start tomcat normally

Now go to eclipse.

Go the Debug perspective
Click on the 'bug' arrow and select 'Debug Configurations'
Double click 'Remote Java Application'
Give it a name EG 'tomcat'
Select the project
Select the server if it is not localhost (the default)
Select the port that you used above eg 8002
Click on the 'debug' button and you are now debugging the tomcat session.

If you want to save that config to use again do the following

Click on the 'bug' arrow and select 'organise Favourites'
Select 'Add'
Search down for the name of the debug session and tick the box
Select OK.

AgileNorth - May 2010

2010-05-18T11:38:00.008+01:00

On Friday I attended AgileNorth May 2010 at Preston UCLAN.

It was an excellent day and thankyou to all the organizers and sponsers Valtech, Thoughtworks to name two.

The opening keynote was by Kevin Murray of Valtech, titled 'Agile in Waterfall Case Studies'. Kevin talked about two case studies where he had been the project manager and introduced agile working practises. Both were large goverment waterfall projects with the latter being a project rescue.

The second project was especially interesting. He was the 14th PM in 2 years and the team members were desperately demotivated. Kevin identified the following benefits:

increased morale

increased motivation

feeling of ownership

issues addressed earlier

visibility to all of status

better quality

less bugs at FAT

Kevin emphasised that introducing agile especially into large government style projects must not:

compromize estimates

question or sacrifice governance

The second talk I attended was by Nick Mckenna of Mckenna Consultants.
Nick is an agile consultant based in Harrogate offering training and consultancy and his talk was titled 'Agile Adoption'. The talk was good and interesting but felt to me like we were getting the first hour of a 1 day talk. His main point was to define a timetable when starting with agile and that could typically be about 3 months. He also emphasised the following:

get everyone to agree

identify roles

spend some time on training

take it slow

prepare to compromise

make it visible

keep everyone informed

the timetable must be agile

review the time table

The third talk was by Paul Shannon (twitter) and Craig Judson (twitter) of Codeweavers titled 'From Chaos to Kanban'

Their talk discussed the life story of how Codeweavers had adopted and adapted agile over the last 2 or 3 years along with the help of the agile consultant Kevin Rutherford. They are clearly exstatic with where they are now in terms of performance and quality. They emphasised to me how agile is in itself agile. how they started doing scrum by the book and ended up with their own kanban solution and board. Their slides are available here.

An excellent lunch was followed by a workshop from Sam Wessel also of Codeweavers on 'CRC - the forgotten Design Tool'. Here is one link to CRC - Class Responsibility Collaborator. This was a fun workshop designing a library application. It showed how to really break down an issue and see your self as the objects in the problem along with their inter-reactions and roles.

The penultimate talk was by the Agile consultant Kevin Rutherford of Rutherford Software (twitter) entitled 'Flow'. The aim of the talk was to show how agile increases the speed with which changes can flow through from requirements to an end product. I really like Kevin's dry and straight talking style. His blog write up of the talk is here. Here are some of his points:

YAGNI - do not do what you do not need now

question or sacrifice governance

thin sliced MMFs (minimal marketable feature) - IE breakdown the work into small chunks

continuous integration

Theory of constraints

The Goal by Goldratt

The closing keynote - phew it was a long day - was by Jim Barritt and Mark Crossfield. Mark is a Thoughtworks ">Thoughtworks consultant and Jim works for Autotrader. There talk covered the issues of working running an agile product with a rapidly expanding workforce.

Two interesting tools that I came across in talks and will investigate soon are

1) Migratordotnet - This is based on the idea of Rails ActiveRecord Migrations. Interestingly it puts the migrations into a dll making them easy to run & install on a windows PC without the need for Rails or other bespoke software.

2) AgileZen - This is an online kanban board, free to use for a single project.

The next AgileNorth will be October time and will be free.

Find other links on AgileNorth via this delicious tag.

Finally here are some twitter links:
@BlueReZZ - Paul Shannon of Codeweavers
@craigjudson - Craig Judson of Codeweavers

SSL, tomcat and self signed certificates

2010-03-03T11:46:00.023Z

I have been through the process of getting an application to work via https before but I have always muddled through and never documented exactly what I have done.

I must also admit that I never quite understood exactly what I had done and why.

One problem is that I can not find one place that covers everything you need in one place.

Now I think I am pretty well there.

This post describes what I have done to get a simple client application working using HTTPS posting to tomcat server and using a self signed certificate with the help of several refereneces in particular:

How to create a self signed certificate
Tomcat SSL Configuration How-To
Developing Web Services with Apache Axis by Tong Ka Iok, Kent ISBN 1-4116-7032-9

The last reference has a chapter which is pretty well SSL for dummies and explains things very nicely.

The steps that need to be done are:

Create a self signed certificate authority (CA)
Sign a test key via the CA
Add both these keys to a keystore
Setup the application (client) and tomcat (the server) to use this keystore.

1) Create a self signed certificate authority (CA) and keystore

This is described in How to create a self signed certificate, but I will show the steps here

What is happening here:

you will create a CA that later will be added to your keystore file. By adding this CA to your keystore you are saying it is trusted like verisign and any certificates signed by it are then also trusted.

1.1) make a directory to hold the certs and keystore. This might be something like:

C:\ssl

1.2) generate a private key for the server

openssl genrsa -des3 -out server.key 1024

1.3) generate a CSR (Certificate Signing Request)

openssl req -new -key server.key -out server.csr

1.4) Remove the passphrasse from the key

cp server.key server.key.org

openssl rsa -in server.key.org -out server.key

1.5) Generate the self signed certificate

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

2) Create a certificate for tomcat and add both to the keystore

2.1) cd to where the keystore is held. This might be something like:

C:\ssl

2.2) Create a keypair for 'tomcat'

keytool -genkey -alias tomcat  -keyalg RSA -keystore tomcat.ks

2.3) Generate a CSR (Certificate Signing Request) for tomcat

keytool -keystore tomcat.ks -alias tomcat -certreq -file tomcat.csr

2.4) create unique serial number

echo 02 > serial.txt

2.5) Sign the tomcat CSR

openssl x509 -CA server.crt -CAkey server.key -CAserial serial.txt -req -in tomcat.csr -out tomcat.cer -days 365

2.6) Import the server CA certificate into the keystore

keytool -import -alias serverCA -file server.crt -keystore tomcat.ks

2.7) add the tomcat certificate to the keystore

keytool -import -alias tomcat -file tomcat.cer -keystore tomcat.ks

3) Tomcat configuration

3.1) Tomcat needs to be configured to use SSL

This is described in more detail at Tomcat SSL Configuration How-To

However all that is needed here is to edit the server.xml to enable SSL

This section is already in the server.xml but commented out.

NB that the location of the keystore has been added.

<!-- Define a SSL HTTP/1.1 Connector on port 8443
         This connector uses the JSSE configuration, when using APR, the 
         connector should be using the OpenSSL style configuration
         described in the APR documentation -->
    <Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
        maxThreads="150" scheme="https" secure="true"
        keystoreFile="C:\ssl\tomcat.ks"
        keystorePass="changeit"
               clientAuth="false" sslProtocol="TLS" />

3.2) test tomcat

start tomcat and go to https://localhost:8443/

your browser will return an error such as "sites certificate is not trusted"

3.3) import the CA certificate server.crt into your browser's tructed root certificates

3.4) test again at https://localhost:8443/

this time you should see the tomcat home page

4) Test your application

4.1) I have a unit test run from eclipse that I have been using to post off to my test server. This produces the error;

Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:174)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:238)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:289)

4.2) The reason for this is that eclipse is not referring to the keystore that we have created. At the time of writing I have not sussed out how to make eclipse use this - Do you know ?

So instead I have added the same two certs to javas keystore

4.3) cd to the directory where java's keystore is held. This might be something like:

C:\java\jdk1.6.0_18\jre\lib\security

4.4) the keystore is a file called cacerts

4.5) copy the files c:\ssl\server.crt and c:\ssl\tomcat.cer to this directory

4.6) import the server CA into the java keystore

keytool -import -alias serverCA -file server.crt -keystore cacerts

4.7 import tomcats cert into the java keystore

keytool -import -alias tomcat -file tomcat.cer -keystore cacerts

5) Test your app again.

Hopefully all will be hunkdory. Enjoy.

6) Caveats:

6.1) the passwords for all keystores and certs are 'changeit'. this is the default keystore password

and I suggest you change this for a production system

6.2) Using a self signed cert is great for a test environment of for a private system but not for a commercial released application. For this you will need to get & pay for a signed certificate from an approved authority such as Verisign.

train times using RESTful urls

2010-02-23T09:46:00.003Z

While travelling by train in this arctic winter I came across this really nice simple train times site using RESTful URLs to great effect.

http://traintimes.org.uk/blackburn/entwsitle/16:00/today

The output is really clear and simple making it great for display on small phone screens.

Apache Ivy - Working with the Apache tutorial

2009-12-04T15:18:00.016Z

Apache Ivy is a dependancy manager and appears to be flavour of the month in some circles and claims to be less complicated than Maven.

Here is a quick tutorial that expands on Apaches tutorial page. They provide one very small build.xml in a style that they say is not best practise for a number of reasons:

it is standalone
it contains the code within the build.xml
it downloads ivy locally instead of using a remote installation

I struggled to find a simple example of a build in the accepted syntax so I will attempt here to describe how this build.xml can be changed in 4 steps to ultimately work in the conventional style with a build.xml and ivy.xml files and a remote installation of ivy.

My next project will be to 'ivyfy' a spring project. Hopefully I will be successfull - watch this space.

prerequisites:

Apache Ant installed to 1.6 or greater

1) The basic Tutorial from Apache Ivy

Essentially follow their instructions & download the build.xml from the tutorial page
I had to edit the downloaded file to remove the dashes at the start of some lines
run 'ant'
I also changed the following line to refer to the latest formal release of ivy, but both will work.

from:

 <property name="ivy.install.version" value="2.0.0-beta1" />

to:

    <property name="ivy.install.version" value="2.1.0" />


2) Tutorial with no ivy
One of things about ivy is that you are supposed to take an existing project and 'ivyfy' - IE remove your local third party jars and rely on ivy to fullfill your dependancies
So this tutorial simply takes the results from the previous example and gets it to work without ivy.
It therefore needs the src folder & its contents, the commons-lang jar in a lib dir in the project and a build.xml
The file structure for this and future tutorials is:
.
./build.xml
./file
./filestructure
./lib
./lib/commons-lang-2.1.jar
./src
./src/example
./src/example/Hello.java
The build.xml required is:
<project name="go-ivy" default="go" >

<property name="build.dir" value="build" />
<property name="src.dir" value="src" />
<property name="lib.path.id" value="lib" />

<path id="compile.classpath">
<fileset dir="${lib.path.id}">
 <include name="**/*.jar"/>
</fileset>
</path>

<!-- =================================
     target: go Go ivy, go!
    ================================= -->
<target name="go" depends=""
       description="--> resolve dependencies, compile and run the project">
   <echo message="NOT using ivy to resolve commons-lang 2.1..."/>

   <echo message="compiling..."/>
   <mkdir dir="${build.dir}" />
   <javac srcdir="${src.dir}" destdir="${build.dir}" >
      <classpath refid="compile.classpath"/>
   </javac>

   <java classname="example.Hello">
       <classpath>
          <fileset dir="${lib.path.id}">
            <include name="**/*.jar"/>
          </fileset>
          <path location="${build.dir}" />
       </classpath>
   </java>
</target>


<!-- =================================
     target: clean         
    ================================= -->
<target name="clean" description="--> clean the project">
   <delete includeemptydirs="true" quiet="true">
       <fileset dir="${src.dir}" />
       <fileset dir="${build.dir}" />
   </delete>
</target>
</project>

3) Tutorial with ivy.xml

In the above example everything is defined in the build.xml. The clever thing with ivy and maven is that your project does not explicitly contain third party jars.
Instead these are defined in a config file, ivy.xml in this case.
This step moves the dependancies defined in build.xml into a seperate ivy.xml
again simply run 'ant' to test.
For this and subsequent tutorials I did not generate the src files. I kept them from the first tutorial
Therefore for this and subsequent tutorials all you need is the src folder with the src file, the build.xml & ivy.xml
Here is the ivy.xml

<ivy-module version="2.0">
<info organisation="Utilisoft" module="Test-withivy.xml"/>
<dependencies>
<dependency org="commons-lang" name="commons-lang" rev="2.1"/>
</dependencies>
</ivy-module>

Here is the new build.xml - I have removed much of the comments to make it smaller.

<project name="go-ivy-with-ivy.xml" default="go" xmlns:ivy="antlib:org.apache.ivy.ant" basedir=".">
<!-- here is the version of ivy we will use. change this property to try a newer
version if you want -->
<property name="ivy.install.version" value="2.1.0" />
<property name="ivy.jar.dir" value="${basedir}/ivy" />
<property name="ivy.jar.file" value="${ivy.jar.dir}/ivy.jar" />

<property name = "ivy.lib.dir" value="${basedir}\newlib" />

<path id="lib.path.id">
  <fileset dir="${ivy.lib.dir}" />
</path>

<property name="build.dir" value="build" />
<property name="src.dir" value="src" />

<!-- =================================
target: go Go ivy, go!
================================= -->
<target name="go" depends="resolve "
description="--> resolve dependencies, compile and run the project">
<echo message="using ivy to resolve commons-lang 2.1 with ivy.xml"/>

<echo message="compiling..."/>
<mkdir dir="${build.dir}" />
<javac srcdir="${src.dir}" destdir="${build.dir}" classpathref="lib.path.id" />

<java classname="example.Hello">
<classpath>
  <path refid="lib.path.id" />
  <path location="${build.dir}" />
</classpath>
</java>
</target>


<!-- =================================
target: clean
================================= -->
<target name="clean" description="--> clean the project">
<delete includeemptydirs="true" quiet="true">
<fileset dir="${src.dir}" />
<fileset dir="${build.dir}" />
</delete>
</target>

<target name="resolve" depends="install-ivy" description="Resolve the dependencies">
<ivy:retrieve/>
</target>


<!-- =================================
target: install-ivy
this target is not necessary if you put ivy.jar in your ant lib directory
if you already have ivy in your ant lib, you can simply remove this
target and the dependency the 'go' target has on it
================================= -->
<target name="install-ivy" depends="download-ivy" description="--> install ivy">
<!-- try to load ivy here from local ivy dir, in case the user has not already dropped
it into ant's lib dir (note that the latter copy will always take precedence).
We will not fail as long as local lib dir exists (it may be empty) and
ivy is in at least one of ant's lib dir or the local lib dir. -->
<path id="ivy.lib.path">
<fileset dir="${ivy.jar.dir}" includes="*.jar"/>
</path>
<taskdef resource="org/apache/ivy/ant/antlib.xml"
    uri="antlib:org.apache.ivy.ant" classpathref="ivy.lib.path"/>
</target>

<target name="download-ivy" unless="skip.download">
<mkdir dir="${ivy.jar.dir}"/>
<!-- download Ivy from web site so that it can be used even without any special installation -->
<echo message="installing ivy..."/>
<get src="http://repo1.maven.org/maven2/org/apache/ivy/ivy/${ivy.install.version}/ivy-${ivy.install.version}.jar" dest="${ivy.jar.file}" usetimestamp="true"/>
</target>
</project>


4) Tutorial with remote Ivy
Hopefully you are still with me. This is the last step in this tutorial set.
The above example still downloads ivy locally 
This example will now use ivy as part of your apache and installation
In the last example a ivy.jar file appeared in an 'ivy' directory. 
Determine the location of your apache ant installation and copy this jar into the apache ant lib directory.
Ensure you have an ANT_HOME environment variable pointing to the apache4 ant installation directory
Below is the new build.xml file you will need.

<project name="go-ivy-with-ivy.xml" default="go" xmlns:ivy="antlib:org.apache.ivy.ant" basedir=".">
<!-- here is the version of ivy we will use. change this property to try a newer
version if you want -->
<property name="ivy.install.version" value="2.1.0" />
<property name="ivy.jar.dir" value="${basedir}/ivy" />
<property name="ivy.jar.file" value="${ivy.jar.dir}/ivy.jar" />

<property name = "ivy.lib.dir" value="${basedir}\newlib" />

<path id="lib.path.id">
       <fileset dir="${ivy.lib.dir}" />
</path>

<property name="build.dir" value="build" />
<property name="src.dir" value="src" />

<!-- =================================
 target: go
           Go ivy, go!
================================= -->
<target name="go" depends="resolve "
   description="--> resolve dependencies, compile and run the project">
<echo message="using ivy to resolve commons-lang 2.1 with ivy.xml"/>

<echo message="compiling..."/>
<mkdir dir="${build.dir}" />
<javac srcdir="${src.dir}" destdir="${build.dir}" classpathref="lib.path.id" />

<echo>
We are now ready to execute our simple program with its dependency on commons-lang.
Let's go!
</echo>
<java classname="example.Hello">
   <classpath>
       <path refid="lib.path.id" />
       <path location="${build.dir}" />
   </classpath>
</java>
</target>

<!-- =================================
 target: clean     
================================= -->
<target name="clean" description="--> clean the project">
<delete includeemptydirs="true" quiet="true">
   <fileset dir="${src.dir}" />
   <fileset dir="${build.dir}" />
</delete>
</target>

<target name="resolve" depends="" description="Resolve the dependencies">
<ivy:retrieve/>
</target>
</project>

And to the future. I have two immediate aims:

Get a build of a spring hibernate using Ivy
Get a project with dependant projects using spring and hibernate using ivy.

oracle - listing all tables in a schema

2009-12-01T14:11:00.002Z

select table_name,

to_number( extractvalue( xmltype(

dbms_xmlgen.getxml('select count(*) c from '||table_name))

,'/ROWSET/ROW/C')) count

from user_tables;

courtesy of Burleson

SQL info for oracle/sqlserver/mysql

2009-11-23T09:56:00.002Z

While performing some testing to ensure my app was compliant with multiple db flavours I came across this site.

It is a useful reference to quickly see how the different flavours perform some common operations.

http://www.sqlinfo.net/