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peterszatmary edited this page Aug 15, 2016 · 3 revisions

What you can find in this maven project and how it works

  • automatization of controlling java source best practises and convetions ( checkstyle, PMD )
  • automatization of controlling test coverage ( Jacoco )
  • controlling version of java in source and target

Checkstyle

on verify maven phase

if there are violations :

Maven ends build with FAILURE and write all violations to stdout :


[INFO] Starting audit...
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:13: error: Must have at least one statement.
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:14: error: '{' is not followed by whitespace.
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:14: error: '}' is not preceded with whitespace.
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:21: error: 'catch' is not followed by whitespace.
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:37: error: '{' is not followed by whitespace.
/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java:20:37: error: '}' is not preceded with whitespace.
Audit done.

Checkstyle can generate also reports but in my opinion this is unnecessary because checkstyle already end the build if there are some violations and every violations puts write on stdout.

Maven code fragment :

<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <version>2.17</version>
                <executions>
                    <execution>
                        <id>checkstyle-validate</id>
                        <phase>validate</phase><!-- when we need to run checkstyle::check -->
                        <configuration>
                            <configLocation>src/main/resources/checkstyle.xml</configLocation>
                            <encoding>${project.build.sourceEncoding}</encoding>
                            <consoleOutput>true</consoleOutput>
                            <failsOnError>true</failsOnError>
                        </configuration>
                        <goals>
                            <goal>check</goal><!-- what from checkstyle is used // checkstyle::check -->
                        </goals>
                    </execution>
                </executions>
            </plugin>

PMD

on verify maven phase

if there are violations :

Maven ends build with FAILURE and write all violations to generated file {your-project-path}/target/pmd.xml:


<?xml version="1.0" encoding="UTF-8"?>
<pmd version="5.3.5" timestamp="2015-12-27T13:04:35.894">
<file name="/home/nue/nue/dev/web/2016/MavenProjectStarter/src/main/java/maven/project/starter/App.java">
<violation beginline="20" endline="20" begincolumn="16" endcolumn="37" rule="EmptyCatchBlock" ruleset="Empty Code" package="maven.project.starter" class="App" method="main" externalInfoUrl="https://pmd.github.io/pmd-5.3.5/pmd-java/rules/java/empty.html#EmptyCatchBlock" priority="3">
Avoid empty catch blocks
</violation>
<violation beginline="20" endline="20" begincolumn="13" endcolumn="14" rule="EmptyTryBlock" ruleset="Empty Code" package="maven.project.starter" class="App" method="main" externalInfoUrl="https://pmd.github.io/pmd-5.3.5/pmd-java/rules/java/empty.html#EmptyTryBlock" priority="3">
Avoid empty try blocks
</violation>
</file>
</pmd>

Ruleset in maven config pom.xml is optional. You can use it like a customization of PMD.

PMD can generate also reports but in my opinion this is unnecessary because PMD already end the build if there are some violations and every violations write to xml file.

Maven code fragment

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-pmd-plugin</artifactId>
                <version>3.6</version>
                <executions>
                    <execution>
                        <id>pmd-validate</id>
                        <phase>validate</phase><!-- when we need to run .... -->
                        <configuration>
                            <linkXRef>false</linkXRef>
                            <rulesets>
                                <ruleset>src/main/resources/pmd.xml</ruleset>
                            </rulesets>
                        </configuration>
                        <goals>
                            <goal>check</goal><!-- what from pmd is used // .... -->
                            <goal>pmd</goal><!-- what from pmd is used // .... -->
                        </goals>
                    </execution>
                </executions>
            </plugin>

Jacoco - The Code coverage tool

There are more code coverage tools. FOr example :

So I decided to use Jacoco because is under development and have more functions and can define percentage and fail if they dont meet.

For first this is code coverage tool. It gets to test phase. Plugin have 3 executions.

  • default-prepare-agent : prepare agent that is used for analysis (without it its impossible do anything).
  • jacoco-default-report : report generating on site phase.
  • jacoco-check : main test analysis on test phase. Test code coverage is here on 0.55 = 55 percent.
  • ...

With Jacoco you need to run mvn test and if you would like to have also reports than run mvn test site (Create for it custom maven command.).

Maven code fragment :


            <!-- JACoCo code coverage plugin -->
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
                <version>0.7.5.201505241946</version>


                <!-- preparing agent that is used for analysis -->
                <executions>
                    <execution>
                        <id>default-prepare-agent</id>
                        <goals>
                            <goal>prepare-agent</goal>
                        </goals>
                    </execution>

                    <!-- creates Jacoco reports on site phase
                        is better keep generating reports on site phase and
                        for developer better life create please custom mvn command with site in it.
                    -->
                    <execution>
                        <id>jacoco-default-report</id>
                        <phase>site</phase>
                        <goals>
                            <goal>report</goal>
                        </goals>
                    </execution>


                    <!-- running analysis on test phase -->
                    <execution>
                        <id>jacoco-check</id>
                        <phase>test</phase>
                        <goals>
                            <goal>check</goal>
                        </goals>
                        <configuration>
                            <rules>
                                <rule implementation="org.jacoco.maven.RuleConfiguration">
                                    <element>BUNDLE</element>
                                    <limits>
                                        <limit implementation="org.jacoco.report.check.Limit">
                                            <counter>INSTRUCTION</counter>
                                            <value>COVEREDRATIO</value>
                                            <minimum>0.55</minimum>
                                        </limit>
                                    </limits>
                                </rule>
                            </rules>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

jacoco-default-report

jacoco-default-report generates for you something like this :

results

jacoco table

jacoco clas example

Controlling version of java on build

For this is used maven-compiler-plugin. I controll target and source java version with it.

Maven code fragment :


            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>

FindBugs

On verify maven phase.

After verify it create 2 files. You can find in it errors.

  • {your-project-path}/target/findbugsXml.xml
  • {your-project-path}/target/findbugs.xml

After this maven tell you if you have errors and end build with FAILURE.


[INFO] 
[INFO] >>> findbugs-maven-plugin:3.0.3:check (findbugs-verify) > :findbugs @ maven.project.starter >>>
[INFO] 
[INFO] --- findbugs-maven-plugin:3.0.3:findbugs (findbugs) @ maven.project.starter ---
[INFO] Fork Value is true
     [java] Warnings generated: 1
[INFO] Done FindBugs Analysis....
[INFO] 
[INFO] <<< findbugs-maven-plugin:3.0.3:check (findbugs-verify) < :findbugs @ maven.project.starter <<<
[INFO] 
[INFO] --- findbugs-maven-plugin:3.0.3:check (findbugs-verify) @ maven.project.starter ---
[INFO] BugInstance size is 1
[INFO] Error size is 0
[INFO] Total bugs: 1
[INFO] Return value of String.isEmpty() ignored in maven.project.starter.App.main(String[]) [maven.project.starter.App, maven.project.starter.App, maven.project.starter.App, maven.project.starter.App, maven.project.starter.App] At App.java:[line 21]Another occurrence at App.java:[line 22]Another occurrence at App.java:[line 23]Another occurrence at App.java:[line 24]Another occurrence at App.java:[line 25] RV_RETURN_VALUE_IGNORED
[INFO] 


To see bug detail using the Findbugs GUI, use the following command "mvn findbugs:gui"

Than you can run mvn findbugs:gui or see in generated files.

mvn findbugs:gui

findbugs.png

Maven code fragment :


            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>findbugs-maven-plugin</artifactId>
                <version>3.0.3</version>
                <configuration>
                    <effort>Max</effort>
                    <threshold>Max</threshold>
                    <xmlOutput>true</xmlOutput>
                </configuration>
                <executions>
                    <execution>
                        <id>findbugs-verify</id>
                        <goals>
                            <goal>check</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
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