What is-pmd
- 1. What is PMD ? PMD is a source code analyzer. It finds unused variables, empty catch blocks, unnecessary object creation, and so forth.
- 2. PMD works by scanning Java code and checks for violations in three major areas: – Compliance with coding standards – Coding antipatterns – Cut and Paste Detector (CPD)
- 3. Compliance with coding standards ● Naming conventions – class, method, parameter and variable names ● Class and method length ● Existence and formatting of comments and JavaDocs
- 4. Coding antipatterns ● Possible bugs - Empty try/catch/finally/switch blocks ● Dead code - Unused local variables, parameters and private methods ● Empty (if/while) statements ● Suboptimal code - wasteful String/StringBuffer usage
- 5. Coding antipatterns (2) Overcomplicated expressions – unnecessary if statements, for loops that could be while loops Duplicate code – copied/pasted code means copied/pasted bugs Classes with high Cyclomatic Complexity measurements
- 6. Cut and Paste Detector (CPD) a tool that scans files and looks for suspect code replication. CPD can be parametrized by the minimum size of the code block.
- 7. Stakeholders ● Developers use PMD to comply with coding standards and deliver quality code. ● Team leaders and Quality Assurance folks use it to change the nature of code reviews. ● Team members can do peer-to-peer discussion PMD has the potential to transform a mechanical and syntax check oriented code review into a to dynamic peer-to-peer discussion.
- 8. Rules PMD comes with many predefined rules; we can add more or customize existing one. EmptyFinallyBlock – Avoid empty finally blocks - these can be deleted UnnecessaryReturn – Avoid unnecessary return statements LongVariable – Detects when a field, local variable is declared with a long name
- 9. PMD rules has been grouped into Rule sets Rule set: Naming Rules – Rule: VariableNamingConventions – Rule: MethodNamingConventions – Rule: ClassNamingConventions – Rule: NoPackage Rule set: Unused Code Rules – Rule: UnusedPrivateField – Rule: UnusedLocalVariable