PmdRulesPrototype

Prototype

Very specific rules but useless on general code. They serve as examples and prototypes to copy from.

---

EntityWithReferences

In a specific Rich Domain Model all Entities (subclasses of Entity) must define their attributes as (subclasses of) `RelationShip`s. Simple attributes are not allowed. To fix this rule, wrap all simple attributes with a `RelationShip` of proper type accordingly.

This rule is defined by the following Java class: org.codecop.pmd.prototype.EntityWithReferences

Example:

public class RelationShip<T> { }
public class BetterRelationShip<T> extends RelationShip<T> { }
public class Entity { }
public class BetterEntity extends Entity { }
public class BadEntity extends BetterEntity {
   private RelationShip<MyString> astring; // ok
   private MyString bstring; // wrong
   private int bint; // wrong
}

---

ImmutableValueObject

In a specific Rich Domain Model all Value Objects (subclasses of `ValueObject`s) must not define their attributes as (subclasses of) `RelationShip`s. Just simple attributes are allowed.

This rule is defined by the following Java class: org.codecop.pmd.prototype.ImmutableValueObject

Example:

public class ValueObject { }
public class BadValueObject extends ValueObject {
   private MyString astring;
   private BetterRelationShip<MyString> bstring; // wrong
   public void changeAstring(MyString string) { // wrong
      astring = string;
   }
}

---

EmptyFunction

Some methods, e.g. toString or getName() in subclasses of Action, must not just return null. If they will never be called, throw a `OperationNotSupportedException`.

This rule is defined by the following XPath expression:

//MethodDeclaration
  [MethodDeclarator[@Image=$method or @Image='toString']]
    [Block//ReturnStatement//NullLiteral]

Example:

public class FooAction {
  public String getName() {
    return null; // should return some string for statistics.
  }
}

This rule has the following properties:

Name	Default value	Description
method	'getName'	Name of the method to check

---

CommitInDBLayer

Services are responsible for maintaining transactions, so classes in the DB layer are not allowed to call Connection.commit. commit is a reserved word and should also not be used as identifier.

This rule is defined by the following XPath expression:

//PrimaryExpression[
   ( PrimaryPrefix/Name[ends-with(@Image, $method)] or PrimarySuffix[@Image=$method] ) and
   //PackageDeclaration[Name[ends-with(@Image, $package) ]]
]

Example:

package some.resultlist;

public class CommitInDBLayerExample {

   public void methodOne() {
      Connection con = getConnection();
      con.commit();
      System.out.println("we did it");
   }
   public void methodTwo() {
      getConnection().commit();
      System.out.println("we did it again");
   }
   public void methodThree() {
      // would be ok, but may warn as well
      other.commit(bla);
   }
   public void okOne() {
      int commit;
      // commit = 3; - false positive
      // other.Somecommit(); - false positive
   }
   public void okTwo() {
      long commit = 3L;
      other.commitIt(bla);
      other.commit2();
   }
}

This rule has the following properties:

Name	Default value	Description
method	'commit'	Name of the commit method
package	'.resultlist'	Suffix of the db layer package name

---

Call4MethodNotInPackage

Only certain classes in $package packages are allowed to call special methods on objects, which are suffixed by $method.

This rule is defined by the following XPath expression:

//PrimaryExpression[
   ( PrimaryPrefix/Name[ends-with(@Image, $method)] or PrimarySuffix[ends-with(@Image, $method)] )
   and
   //PackageDeclaration[Name[ not (ends-with(@Image, $package)) ]]
]

Example:

package some.notjunit;

public class BadGuy {

   public void method() {
      Object con = getObject();
      con.run4Test();
      int result = con.run4Test(params);
      System.out.println("we did it");

      getObject().run4Test();
      int res = getObject().run4Test(params);
      System.out.println("we did it again");
   }

   public void method4Test() { } // is allowed
}

This rule has the following properties:

Name	Default value	Description
method	'4Test'	Suffix of the method name
package	'.junit'	Suffix of the allowed package name

---

MoreThanOneCustomLogger

Normally only one logger is used in each class.

This rule is defined by the following XPath expression:

//ClassOrInterfaceBody[
  count(//VariableDeclarator[parent::FieldDeclaration][../Type/ReferenceType/ClassOrInterfaceType[@Image=$logger]]) > 1
]

Example:

class Foo {
   LoggerImpl logger = LoggerUtil.getLogger(Foo.class);
   // It is very rare to see two loggers on a class, normally
   // log information is multiplexed by levels
   LoggerImpl log2 = LoggerUtil.getLogger(Foo.class.getName());
}

This rule has the following properties:

Name	Default value	Description
logger	'LoggerImpl'	Name of the logger type

---

CustomLoggerIsNotStaticFinal

In most cases, the Logger can be declared private, static and final.

This rule is defined by the following XPath expression:

//VariableDeclarator[parent::FieldDeclaration][
  ../Type/ReferenceType/ClassOrInterfaceType[@Image=$logger] and
  ( ..[@Final='false'] or ..[@Static='false'] or .. [@Private='false'] )
]

Example:

class Foo {
    LoggerImpl logger = LoggerUtil.getLogger(Foo.class);
    // It is much better to declare the logger as follows
    // static final LoggerImpl logger = LoggerUtil.getLogger(Foo.class);
}

This rule has the following properties:

Name	Default value	Description
logger	'LoggerImpl'	Name of the logger type

---

NoAttrInClass

This class is shared by threads but not threadsafe. Therefore it must only have final members.

This rule is defined by the following XPath expression:

//FieldDeclaration[@Final='false' and ../../..[ends-with(@Image,$suffix)]]

Example:

public class AdWorxChannelPolicy {
   private final String channel; // ok
   private boolean showIfSearchedInRegion; // not ok
}
// other class
public class AdWorxChannelPolicyKey {
   private final String channel;  // ok
   private boolean showIfSearchedInRegion; // ok
}

This rule has the following properties:

Name	Default value	Description
suffix	'Policy'	Class name suffix

---

TypeNotAllowed

The use of this type is not allowed.

This rule is defined by the following XPath expression:

//ClassOrInterfaceType[@Image=$simple or @Image=$full]

Example:

class MyClass extends OtherClass {
   public void myMethod() {
      try {
         // ...
         throw new org.codecop.HBDException("..."); // "throw new HBDException" is not allowed!
      } catch(HBDException e) { // "catch HBDException" is not allowed!
         // ...
      }
   }
}

This rule has the following properties:

Name	Default value	Description
simple	'HBDException'	Forbidden type simple name
full	'org.codecop.HBDException'	Forbidden type full name

---

ActionHasNoShortName

Certain classes need to define and redefine a method on their own regardless of superclasses have provided it or not.

This rule is defined by the following XPath expression:

//ClassOrInterfaceDeclaration[
  ends-with(@Image, $suffix) and
  not (ends-with(@Image,'HelperAction')) and
  @Abstract='false' and
  count(//MethodDeclarator[@Image=$method])=0
]

Example:

public class FooAction {
   public String getXActionShortName() { // typo occured
      return "abc";
   }
}

This rule has the following properties:

Name	Default value	Description
suffix	'Action'	Class name suffix
method	'getActionShortName'	Name of the method to implement

---

JUnitTestHasWrongName

All concrete JUnit tests must be named to the sheme of ending with Test to be identified and run automatically.

This rule is defined by the following XPath expression:

//ClassOrInterfaceDeclaration[
   not (ends-with(@Image, $suffix)) and
   not (ends-with(@Image, 'TestManuell')) and
   not (@Image='TCInit') and
   @Abstract='false' and
   //PackageDeclaration[Name[ ends-with(@Image, $package) ]]
]

Example:

package some.junit;

class BadTestClass {
  // this does not end with Test
}

abstract class GoodAbstract {
   // is abstract, name as it likes
}

class GoodTest {
   // ok
}

This rule has the following properties:

Name	Default value	Description
package	'.junit'	Suffix of the package name
suffix	'Test'	Mandatory suffix of the class name

---

NewEnumOnlyInside

Enums are special instances and not meant to be created by other classes, instead use a getEnumFor(value) on the Enum itself.

This rule is defined by the following XPath expression:

//AllocationExpression[
   ends-with(ClassOrInterfaceType/@Image, $suffix) and
   (count(ArrayDimsAndInits)=0) and
   not (//ClassOrInterfaceDeclaration/@Image=ClassOrInterfaceType/@Image)
]

Example:

class MyEnum {
   public void foo() {
      new MyEnum(); // is ok
   }
}
class OtherEnum {
   public void foo() {
      new MyEnum(); // is forbidden
   }
}
class OtherClass {
   public void foo() {
      new MyEnum[0]; // array is ok
   }
}

This rule has the following properties:

Name	Default value	Description
suffix	'Enum'	Enum type name suffix