13 Quality

Most Important Concepts / Code

SpotBugs

• SpotBugs in Eclipse

• To install the SpotBugs plugin:

  • Help -> Eclipse Marketplace -> search for SpotBugs

• To use SpotBugs Bugs:

  • Window -> Preferences -> Java -> SpotBugs -> slide "Minimum rank to report" all the way to the right (20)

  • Right click on a Java project in Package Explorer -> Spot Bugs -> Find Bugs

  • Problem markers will be displayed in source windows and in Window -> Show View -> Other -> SpotBugs -> Bug Explorer

    • If no bugs are being found, first make sure you have a bug by adding the following into a method: System.out.println("bug".substring(0)); then save the file and do Find Bugs

    • If that line doesn't show up as a bug, uninstall and reinstall SpotBugs using Help -> Installation Details

    • Scanner scan = new Scanner(System.in, "UTF-8");

Javadocs

1. Create / format documentation

   1. In Eclipse: Source -> Generate Element Comment (Alt + Shift + J) when your cursor is on the line for every class, field, constructor, and method declaration

   2. Description

      1. A required component of every doc.

      2. The first sentence (end in a period). It should be a summary sentence, concise but complete.

      3. Optionally, include an additional <p> tag and a longer description.

   3. Block tags:

      1. At a minimum, include the following:

         1. For a class

            1. @author - your name

         2. For a method

            1. @param - a description of the parameter variable, if there is one

            2. @return - a description of the returned value, if the method returns something

   4. More comprehensive information: How to Write Doc Comments

2. Create and access Javadoc file

   1. Project -> Generate Javadoc

      1. javadoc command is the path to your javadoc.exe. Probably in C:\Program Files\Java\jdk1.n.n_n\bin

   2. Find generated web page at workspace/projectname/doc/index.html

Sample doc comments in a class

/**

* Represents a student enrolled in the school.

* A student can be enrolled in many courses.

* @author Your Name

*/

public class Student {

/**

* The first and last name of this student.

*/

private String name;

/**

* Gets the first and last name of this Student.

* @return this Student's name.

*/

public String getName() {

return name;

}

/**

* Changes the name of this Student.

* This may involve a lengthy legal process.

* @param newName This Student's new name.

* Should include both first

* and last name.

*/

public void setName(String newName) {

name = newName;

}

}

Checkstyle

• To install the Checkstyle plugin: Checkstyle Installation

• To use: right click on the project in the Package Explorer, find Checkstyle, then Check code with Checkstyle

• Style errors will appear in the Problems tab. Eclipse: Window -> Show View -> Problems

• Tips:

  • After each change to your code, save the file and go through the process to check the style again

  • If you don't see Checkstyle when you right click your project, update Eclipse.

  • See Style focus for Eclipse tips related to indentation.

  • You may need to highlight a tab character, and do Edit -> Find/Replace to replace with 2 spaces.