##### Overview

- Download PMD 5.0.4
- What's new in PMD 5.0.4
- PMD in the news
- PMD-related products and books
- Best practices
- Future directions
- Similar projects
- Credits
- License
- What does 'PMD' mean?

##### Usage

- Installation
- Command line usage
- Ant task usage
- Maven plugin usage
- Mvn plugin usage
- IDE plugin usage
- Suppressing warnings
- Finding duplicated code
- JSP support

##### Customizing PMD

- Compiling PMD
- How to write a rule
- Writing XPath rules
- How to make a rule set
- How it works
- Rule guidelines
- PMD developers information
- PMD Release Process

##### For example

- Run PMD on a Sourceforge project

##### Misc.

- XPath tutorial (Gregorian)

##### Rule Sets

- ecmascript
  - Basic Ecmascript
  - Braces
  - Unnecessary
- java
  - Android
  - Basic
  - Braces
  - Clone Implementation
  - Code Size
  - Comments
  - Controversial
  - Coupling
  - Design
  - Empty Code
  - Finalizer
  - Import Statements
  - J2EE
  - JavaBeans
  - JUnit
  - Jakarta Commons Logging
  - Java Logging
  - Migration
  - Naming
  - Optimization
  - Strict Exceptions
  - String and StringBuffer
  - Security Code Guidelines
  - Type Resolution
  - Unnecessary
  - Unused Code
- jsp
  - Basic JSF
  - Basic JSP
- xml
  - Basic XML
- xsl
  - XPath in XSL

##### Project Documentation

- Project Information
- Project Reports

## Type Resolution

These are rules which resolve java Class files for comparison, as opposed to a String

### LooseCoupling

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.

### CloneMethodMustImplementCloneable

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.

### UnusedImports

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.

### SignatureDeclareThrowsException

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