Since: PMD 3.9
Avoid using implementation types (i.e., HashSet); use the interface (i.e, Set) instead
This rule is defined by the following Java class: net.sourceforge.pmd.lang.java.typeresolution.rules.LooseCoupling
Example(s):
import java.util.ArrayList;
import java.util.HashSet;
public class Bar {
// Use List instead
private ArrayList list = new ArrayList();
// Use Set instead
public HashSet getFoo() {
return new HashSet();
}
}
This rule has the following properties:
| Name | Default Value | Description |
|---|---|---|
| violationSuppressRegex | Suppress violations with messages matching a regular expression | |
| violationSuppressXPath | Suppress violations on nodes which match a given relative XPath expression. |
Since: PMD 3.9
The method clone() should only be implemented if the class implements the Cloneable interface with the exception of a final method that only throws CloneNotSupportedException. This version uses PMD's type resolution facilities, and can detect if the class implements or extends a Cloneable class.
This rule is defined by the following Java class: net.sourceforge.pmd.lang.java.typeresolution.rules.CloneMethodMustImplementCloneable
Example(s):
public class MyClass {
public Object clone() throws CloneNotSupportedException {
return foo;
}
}
This rule has the following properties:
| Name | Default Value | Description |
|---|---|---|
| violationSuppressRegex | Suppress violations with messages matching a regular expression | |
| violationSuppressXPath | Suppress violations on nodes which match a given relative XPath expression. |
Since: PMD 4.0
Avoid unused import statements. This rule will find unused on demand imports, i.e. import com.foo.*.
This rule is defined by the following Java class: net.sourceforge.pmd.lang.java.typeresolution.rules.imports.UnusedImports
Example(s):
import java.io.*; // not referenced or required
public class Foo {}
This rule has the following properties:
| Name | Default Value | Description |
|---|---|---|
| violationSuppressRegex | Suppress violations with messages matching a regular expression | |
| violationSuppressXPath | Suppress violations on nodes which match a given relative XPath expression. |
Since: PMD 4.0
It is unclear which exceptions that can be thrown from the methods. It might be difficult to document and understand the vague interfaces. Use either a class derived from RuntimeException or a checked exception. JUnit classes are excluded.
This rule is defined by the following Java class: net.sourceforge.pmd.lang.java.typeresolution.rules.SignatureDeclareThrowsException
Example(s):
public void methodThrowingException() throws Exception {
}
This rule has the following properties:
| Name | Default Value | Description |
|---|---|---|
| IgnoreJUnitCompletely | false | If true, all methods in a JUnit testcase may throw Exception |
| violationSuppressRegex | Suppress violations with messages matching a regular expression | |
| violationSuppressXPath | Suppress violations on nodes which match a given relative XPath expression. | |
| IgnoreJUnitCompletely | false | Allow all methods in a JUnit testcase to throw Exceptions |