PDM 使用

PDM下载地： http://pmd.sourceforge.net/

PMD scans Java source code and looks for potential problems like:

• Possible bugs - empty try/catch/finally/switch statements
• Dead code - unused local variables, parameters and private methods
• Suboptimal code - wasteful String/StringBuffer usage
• Overcomplicated expressions - unnecessary if statements, for loops that could be while loops
• Duplicate code - copied/pasted code means copied/pasted bugs

PMD的所有当前的Rulesets：
List of rulesets and rules contained in each ruleset.

• Android Rules: These rules deal with the Android SDK, mostly related to best practices. To get better results, make sure that the auxclasspath is defined for type resolution to work.
• Basic JSF rules: Rules concerning basic JSF guidelines.
• Basic JSP rules: Rules concerning basic JSP guidelines.
• Basic Rules: The Basic Ruleset contains a collection of good practices which everyone should follow.
• Braces Rules: The Braces Ruleset contains a collection of braces rules.
• Clone Implementation Rules: The Clone Implementation ruleset contains a collection of rules that find questionable usages of the clone() method.
• Code Size Rules: The Code Size Ruleset contains a collection of rules that find code size related problems.
• Controversial Rules: The Controversial Ruleset contains rules that, for whatever reason, are considered controversial. They are separated out here to allow people to include as they see fit via custom rulesets. This ruleset was initially created in response to discussions over UnnecessaryConstructorRule which Tom likes but most people really dislike :-)
• Coupling Rules: These are rules which find instances of high or inappropriate coupling between objects and packages.
• Design Rules: The Design Ruleset contains a collection of rules that find questionable designs.
• Finalizer Rules: These rules deal with different problems that can occur with finalizers.
• Import Statement Rules: These rules deal with different problems that can occur with a class' import statements.
• J2EE Rules: These are rules for J2EE
• JavaBean Rules: The JavaBeans Ruleset catches instances of bean rules not being followed.
• JUnit Rules: These rules deal with different problems that can occur with JUnit tests.
• Jakarta Commons Logging Rules: The Jakarta Commons Logging ruleset contains a collection of rules that find questionable usages of that framework.
• Java Logging Rules: The Java Logging ruleset contains a collection of rules that find questionable usages of the logger.
• Migration Rules: Contains rules about migrating from one JDK version to another. Don't use these rules directly, rather, use a wrapper ruleset such as migrating_to_13.xml.
• Migration13: Contains rules for migrating to JDK 1.3
• Migration14: Contains rules for migrating to JDK 1.4
• Migration15: Contains rules for migrating to JDK 1.5
• MigratingToJava4: Contains rules for migrating to JDK 1.5
• Naming Rules: The Naming Ruleset contains a collection of rules about names - too long, too short, and so forth.
• Optimization Rules: These rules deal with different optimizations that generally apply to performance best practices.
• Strict Exception Rules: These rules provide some strict guidelines about throwing and catching exceptions.
• String and StringBuffer Rules: These rules deal with different problems that can occur with manipulation of the class String or StringBuffer.
• Security Code Guidelines: These rules check the security guidelines from Sun, published at http://java.sun.com/security/seccodeguide.html#gcg
• Type Resolution Rules: These are rules which resolve java Class files for comparisson, as opposed to a String
• Unused Code Rules: The Unused Code Ruleset contains a collection of rules that find unused code.

下载PMD解压后，直接在bin目录中，就可以使用PMD了
  pmd 需要检测的Java源码文件名/源码所在的目录/Jar文件等 xml（格式：xml输出， or text输出，html、nicehtml） 进行检验的规则(如：rulesets/unusedcode.xml)
或者简写成：

  java net.sourceforge.pmd.PMD /path/to/source text basic,imports,unusedcode

pmd的其他一些参数：

• The command line interface also accepts the following optional arguments:
• -debug - prints a stacktrace if an error is encountered
• -shortnames - puts shortened names in the report. This only works if the filename argument is a single directory
• -targetjdk [1.3|1.4|1.5|1.6] - selects either JDK 1.3, 1.4, 1.5 or 1.6 language compatibility; default is 1.5
• -encoding Cp1252 - uses the specified encoding for reading the source code files
• -excludemarker NOPMDFORME - uses the specified string of characters as the marker for PMD to ignore. The default string is "NOPMD".
• -linkprefix - path to HTML source, for summary html renderer only.
• -lineprefix - custom anchor to affected line in the source file, for summary html renderer only.
• -minimumpriority - The rule priority threshold; rules with lower priority than they will not be used.
• -xslt FILENAME - This option overrides the default XSL stylesheet used by nicehtml renderer.