Thursday, 3 August 2017

Thames path improvements - Letter to Oxfordshire County Council

I have sent the following letter to LTS.Team AT in response to




I have submitted the following via the questionnaire:


The Oxpens bridge should move upstream to parallel the railway bridge with a path extension besides railway to station. Getting from Thames/railway station to canal towpath and up to Kidlington Airport and Kidlington new housing extension needed. Second bridge, again parallel to rail bridge needed to access Science Park.


I have used the Thames towpath for commuting to Osney Mead industrial estate for three months and for work on Cornmarket for three years. I also used the path for three months to commute to Kidlington (Oxford Airport) but it is too arduous and much to my sadness I now cycle on the road, so have trenchant views on the difficulty of cycle commuting in Oxford.


I understand that there is a plan to build many new houses in the Kidlington gap, between Summertown and Kidlington.


These new commuters would very much appreciate a functioning cycle route into the centre of town.


The new Oxford Parkway should be integrated into this cycle route.


The problem facing cyclists is not how to get from the towpath to the Centre, this is served by the pipe bridge, the pedestrian crossing down stream and Folley Bridge. What is needed is easy access to the railway station which could be easily achieved by a bridge parallel to the railway bridge and then along railway land to the station itself.


Cyclists wishing to get from the Thames to the canal have to continue to Osney, cross the road and then fiddle around the Thames onto the canal path, which is in a very poor state, then up to Kingsbridge and all the way through Kidlington to the Oxford Airport.


Finally the Thames path should connect the Science Park, and the planned new housing at Littlemore. This again could be achieved by a cycle bridge parallel to the existing railway bridge down stream from the bypass underpass.


I really welcome the proposals but would urge you to consider extending its scope and vision. This could be such a good route and would show that Oxford is a cycling city.


best regards Tim Pizey

-- Tim Pizey -

Wednesday, 28 June 2017

Tell, don't ask

More than twelve years ago Tim Joyce passed on some programming wisdom:

With programs tell don't ask, vice versa for people.

This was a bit abstract for me at the time but last night it came back to me as what is wrong with the code I am currently working on. We store our application configuration in a table in the system's target database and whenever some configuration is needed it is looked up in the database. There was no problem with this approach when the code was written because JUnit had not been invented and testing was not the main part of our discipline. However to write a test we would need a database present, which is an obstacle to fast, distinct, unit tests and has been a blocker to writing tests.

Noncompliant Code Example

public class Example { 
  private String path;
  public void logPath() {
    try {
      path = CachedSystemParameter.getInstance().
    } catch (SystemParameterException e) {
      logger.error("[BUSINESS] Error while retrieving system parameter PATH", e);
    }"Path: " + path);

Compliant Code Example

By adding sftpPath to the class constructor we can test the business logic without the need for a database fixture.
public class Example { 

  private String path;

  public Example() { 

  public Example(String path) { 
    this.path = path;

  public void logPath() {"Path: " + path);

Thursday, 4 May 2017

Testing java slf4j over log4j logging in JUnit using SLF4J Test

Testing logging on failure paths has two problems:

  • It is hard to get the log message text
  • The logger outputs to the test log
The first leads to compromises eg verifying only that a message was logged, the second makes you, the programmer, think an error has occurred when the tests in fact passed.

Code to test

public class Sut { 
    public String perform() {
        getLog().debug("In perform");
        return "Hello world";

My clunky PowerMock Solution

My approach was problematic as it required the use of PowerMock which is as powerful as nitroglycerin.

Test Code

public class SutTest {

    public void testPerform() {
        Logger mockLog = mock(Logger.class);

        assertEquals("Hello world", new Sut().perform());
        verify(mockLog, times(1)).debug(startsWith("In perform"));

Elegant SLF4j Test Solution

The slf4j-test project by RobElliot266 provides a logger which stores messages and so can be asserted against.

POM Setup

Add the following to your dependencies


To ensure that this logger is used during tests only and that it takes precedence over the production logger in the test class path ensure the test logger is the first logger mentioned in the dependencies block and has a test scope.

As an additional measure you can explicitly exclude the production logger from the test class path:


Test Code

public class SutTest {
  public void testPerform() {
    assertEquals("Hello world", new Sut().perform());
    assertEquals("Testing", logger.getLoggingEvents().get(0).getMessage());

Much thanks to RobElliot266 for an neat solution to a problem that has been bugging me for a while.