Use checkstyle for smell detection

Here's a sample. If I get some time I'll add them in.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE module PUBLIC
"-//Puppy Crawl//DTD Check Configuration 1.1//EN"
"http://www.puppycrawl.com/dtds/configuration_1_1.dtd">

<module name="Checker">
<module name="TreeWalker">
<!-- Programming Practice -->

<module name="VisibilityModifier"/>
<module name="EqualsHashCode"/>
<module name="HiddenField"/>
<module name="IllegalInstantiation">
<property name="classes" value="java.lang.Boolean,java.lang.String"/>
</module>
<module name="InnerAssignment"/>
<module name="SimplifyBooleanExpression"/>
<module name="SimplifyBooleanReturn"/>
<module name="UpperEll"/>
<module name="MissingSwitchDefault"/>
<module name="HideUtilityClassConstructor"/>
<module name="DoubleCheckedLocking"/>
<module name="FinalClass"/>
<module name="EmptyStatement"/>
<module name="ParameterNumber">
<property name="max" value="7"/>
</module>
<module name="MagicNumber"/>

<module name="GenericIllegalRegexp">
<property name="format" value="System\.out\.print|System\.err\.print|\.printStackTrace"/>
</module>

<module name="ReturnCountCheck"/>
<module name="AbstractClassNameCheck"/>
<module name="NestedTryDepthCheck"/>
<module name="NestedIfDepthCheck"/>
<module name="IllegalCatchCheck"/>
<module name="ThrowsCountCheck"/>
<module name="IllegalTypeCheck"/>
<module name="IllegalTokenCheck"/>
<module name="ParameterAssignmentCheck"/>
<module name="PackageDeclarationCheck"/>
<module name="MutableExceptionCheck"/>
<module BooleanExpressionComplexityCheck"/>
<module name="CyclomaticComplexityCheck"/>
<module name="NPathComplexityCheck"/>
<module name="ExecutableStatementCountCheck"/>
<module name="ClassFanOutComplexityCheck"/>
<module name="ClassDataAbstractionCouplingCheck">
<property name="max" value="10"/>
</module>
<module name="FinalFieldCheck"/>
<module name="ReturnFromCatchCheck"/>
<module name="ReturnFromFinallyCheck"/>
<module name="IllegalThrowsCheck"/>

<!-- Consistency -->

<module name="Header">
<property name="headerFile" value="$

/checkstyle-header.txt"/>
</module>
<module name="IllegalImport"/>
<module name="RedundantImport"/>
<module name="UnusedImports"/>
</module>
</module>

About half of your suggested checks are already in the drools/checkstyle.xml file. I am adding the other half.

GenericIllegalRegexp which looks for System.out/err.print may not be a good addition, because, to my knowledge, Bob hasn't allowed Drools to gain a dependency on a logging mechanism (aka log4j), so System.out/err.print is our only option.

Great stuff Andy (as always). I figured many would already be there I just wasn't sure. I think the main thing I'd like to work towards is having it break the build

I found Simon's Check JAR at:
http://www.redhillconsulting.com.au/blogs/simon/archives/000137.html

It will have to be integrated into our Maven build somehow before the following checks will work: FinalFieldCheck, ReturnFromCatchCheck, ReturnFromFinallyCheck.

The check IllegalThrowsCheck wasn't in Simon's Check JAR, so I don't know where that is supposed to come from.

I'm assigning this to Simon so that he can enable the remaining recommended Checks and configure Maven to use his Check JAR.

Bob and I have asked andy to remove the one that doesn't allow shadowed field names.
public setName(String name)
{
this.name = name;
}

Agreed. As I said I just copied the file from an existing project. I'm a bit of a code quality N**zi but it has to be a team thing. Was really just raising the profile of the checkstyle stuff for the project as a whole. As we can see, we will start to be judged not just on functionality but also on quality. Some serious organisations will start to get interested. Just want to be ready for them

checkstyle.xml updated with all of Simon's recommended Checks, except for the ones that are not supported by the Maven CheckStyle-plugin.