Month: November 2008

AbstractTransactionalDataSourceSpringContextTests and auto-wire

I got stuck last week because we have two DataSource beans with different names, for different databases. My AbstractTransactionalDataSourceSpringContextTests Unit Tests did not like this:

Unsatisfied dependency expressed through bean property 'dataSource':
No unique bean of type [javax.sql.DataSource] is defined:
expected single matching bean but found 2

The problem is that by default AbstractTransactionalDataSourceSpringContextTests is set to autowire by type. I changed this to autowire by name, in the getConfigLocations method:

protected String[] getConfigLocations(){
        setAutowireMode(AUTOWIRE_BY_NAME);
        return new String[]{ "test-applicationContext.xml" };
    }

To get the Daos I was testing injected, all I had to do was create getters and setters with the same names as I had specified for for the Dao beans in my applicationContext. So little to do!

25

jasper reports – parameters for ‘in clause’

I found a really useful function today, allowing you to supply a List as a parameter, and use in your SQL Query  with IN or NOT IN.

Supply the parameter as a List:

<parameter name="myList" isForPrompting="true" class="java.util.List"/>

Then use the the function

$X{IN, <column>, <param>}

For example

<queryString><![CDATA[SELECT *
FROM mytable WHERE $X{IN, mycolumn,myList}]]>
</queryString>

Very useful!

54

Spring web mvc and url mapping

Back to an old problem that I haven’t resolved. I want to map everything to my Spring Controller. So I can have urls like mydomain.com/this and mydomain.com/that

So I put this in my web.xml

<servlet-mapping>
	<servlet-name>myservlet</servlet-name>
	<url-pattern>/*</url-pattern>
</servlet-mapping>

I’m using the Spring Dispatcher Servlet, with jsp as the view, using
org.springframework.web.servlet.view.InternalResourceViewResolver in my spring config.  But it can’t find the view. I get:

NOT_FOUND RequestURI=/webapp/WEB-INF/jsp/main.jsp

In the logs is:
WARN org.springframework.web.servlet.PageNotFound
– No mapping found for HTTP request with URI [/webapp/WEB-INF/jsp/main.jsp] in
DispatcherServlet with name ‘myservlet’

So the request for the view is going through the Dispatcher Servlet too. Not sure how to get around this! This blog is turning into a list of problems, rather than solutions…

47

optional parameters in Jasper reports

I have been mainly writing Jasper reports this week. There seems to be a dearth of documentation (unless you pay for ‘The Definitive Guide’), but a combination of iReport and trial and error seems to be working.

I wanted to reuse the same report with some optional parameters – add an additional condition to the where clause if a certain paramteter was supplied. I realise that I can pass an entire SQL statement into the report, or even some objects containing the data, but I like the consistency of having valid SQL in the report and letting Jasper substitute the parameters appropriately.

My solution was to use the ‘case’ statement (I’m using PostgreSQL):

WHERE manager = (case when $P{manager} != '' then $P{manager} else manager end)

I guess there would be performance implications on a big dataset, but it seems to work.

46