SonarQube doesn't generate "duplications" information - maven

Question

I've managed to install SonarQube 5.1 using the official docker image from SonarSource.
I am actually running sonar using the default H2 DB and I have got almost eveything woking for my demo Java project: Coverage, unit tests and issues.
However, the duplications are 0%. I have created a test classes with the following code:
public class Test {
public Test() {
for(int i = 0; i < 10; i++)
{
System.out.println("Test");
System.out.println("Test");
System.out.println("Test");
}
for(int i = 0; i < 10; i++)
{
System.out.println("Test");
System.out.println("Test");
System.out.println("Test");
}
}
How can be the duplications 0%? I think something is not working in my set...
In addition, Sonar has detected some major issues in my class, but nothing related with the duplications:
Hide this public constructor
Replace this usage of System.out or System.err by a logger
In order to generate the sonar report, I am executing sonar:sonar using maven. That's the output:
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building demoservice 0.1.0.-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- sonar-maven-plugin:2.6:sonar (default-cli) # demoservice ---
[INFO] SonarQube version: 5.1
INFO: Default locale: "en_GB", source code encoding: "UTF-8"
INFO: Work directory: W:\DemoService\target\sonar
INFO: SonarQube Server 5.1
[INFO] [15:52:47.080] Load global repositories
[INFO] [15:52:47.290] Load global repositories (done) | time=212ms
[INFO] [15:52:47.293] Server id: 20150917085707
[INFO] [15:52:47.295] User cache: C:\Users\jose.valencia\.sonar\cache
[INFO] [15:52:47.303] Install plugins
[INFO] [15:52:47.402] Install JDBC driver
[INFO] [15:52:47.412] Create JDBC datasource for jdbc:h2:tcp://localhost:9092/sonar
[INFO] [15:52:48.524] Initializing Hibernate
[INFO] [15:52:50.183] Load project repositories
[INFO] [15:52:51.840] Load project repositories (done) | time=1657ms
[INFO] [15:52:51.841] Load project settings
[INFO] [15:52:52.252] Load technical debt model
[INFO] [15:52:52.285] Apply project exclusions
[INFO] [15:52:53.136] ------------- Scan demoservice
[INFO] [15:52:53.139] Load module settings
[INFO] [15:52:53.238] Language is forced to java
[INFO] [15:52:53.244] Load rules
[INFO] [15:52:53.437] Base dir: W:\DemoService
[INFO] [15:52:53.437] Working dir: W:\DemoService\target\sonar
[INFO] [15:52:53.438] Source paths: pom.xml, src/main/java
[INFO] [15:52:53.438] Test paths: src/test/java
[INFO] [15:52:53.439] Binary dirs: target/classes
[INFO] [15:52:53.439] Source encoding: UTF-8, default locale: en_GB
[INFO] [15:52:53.439] Index files
[INFO] [15:52:53.456] 9 files indexed
[INFO] [15:52:53.642] Quality profile for java: Sonar way
[INFO] [15:52:53.672] Sensor JavaSquidSensor
[INFO] [15:52:55.794] Java Main Files AST scan...
[INFO] [15:52:55.796] 6 source files to be analyzed
[INFO] [15:52:57.434] Java Main Files AST scan done: 1640 ms
[INFO] [15:52:57.435] 6/6 source files have been analyzed
[INFO] [15:52:57.437] Java bytecode scan...
[INFO] [15:52:57.551] Java bytecode scan done: 114 ms
[INFO] [15:52:57.551] Java Test Files AST scan...
[INFO] [15:52:57.552] 3 source files to be analyzed
[INFO] [15:52:58.106] Java Test Files AST scan done: 555 ms
[INFO] [15:52:58.107] 3/3 source files have been analyzed
[INFO] [15:52:58.111] Package design analysis...
[INFO] [15:52:58.164] Package design analysis done: 53 ms
[INFO] [15:52:58.193] Sensor JavaSquidSensor (done) | time=4521ms
[INFO] [15:52:58.193] Sensor Lines Sensor
[INFO] [15:52:58.196] Sensor Lines Sensor (done) | time=3ms
[INFO] [15:52:58.196] Sensor QProfileSensor
[INFO] [15:52:58.201] Sensor QProfileSensor (done) | time=5ms
[INFO] [15:52:58.201] Sensor InitialOpenIssuesSensor
[INFO] [15:52:58.270] Sensor InitialOpenIssuesSensor (done) | time=69ms
[INFO] [15:52:58.270] Sensor ProjectLinksSensor
[INFO] [15:52:58.286] Sensor ProjectLinksSensor (done) | time=16ms
[INFO] [15:52:58.286] Sensor VersionEventsSensor
[INFO] [15:52:58.309] Sensor VersionEventsSensor (done) | time=23ms
[INFO] [15:52:58.309] Sensor Maven dependencies
[INFO] [15:53:01.186] Sensor Maven dependencies (done) | time=2877ms
[INFO] [15:53:01.186] Sensor CoberturaSensor
[INFO] [15:53:01.186] parsing W:\DemoService\target\site\cobertura\coverage.xml
[INFO] [15:53:01.283] Sensor CoberturaSensor (done) | time=97ms
[INFO] [15:53:01.283] Sensor SurefireSensor
[INFO] [15:53:01.284] parsing W:\DemoService\target\surefire-reports
[INFO] [15:53:01.302] Sensor SurefireSensor (done) | time=19ms
[INFO] [15:53:01.302] Sensor SCM Sensor
[INFO] [15:53:01.309] SCM provider for this project is: git
[INFO] [15:53:01.313] 1 files to be analyzed
[INFO] [15:53:01.548] 1/1 files analyzed
[INFO] [15:53:01.549] Sensor SCM Sensor (done) | time=247ms
[INFO] [15:53:01.549] Sensor CPD Sensor
[INFO] [15:53:01.549] JavaCpdEngine is used for java
[INFO] [15:53:01.549] Cross-project analysis disabled
[INFO] [15:53:01.595] Sensor CPD Sensor (done) | time=46ms
[INFO] [15:53:01.596] No quality gate is configured.
[INFO] [15:53:01.642] Compare to previous analysis (2015-09-17)
[INFO] [15:53:01.651] Compare over 30 days (2015-08-18, analysis of Wed Sep 16 17:23:06 BST 2015)
[INFO] [15:53:01.944] Execute decorators...
[INFO] [15:53:02.987] Store results in database
[INFO] [15:53:04.851] Analysis reports generated in 75ms, dir size=8 KB
[INFO] [15:53:04.879] Analysis reports compressed in 28ms, zip size=8 KB
[INFO] [15:53:04.914] Analysis reports sent to server in 35ms
[INFO] [15:53:04.915] ANALYSIS SUCCESSFUL, you can browse http://10.1.2.77:9001/dashboard/index/pbs.demoservice:demoservice
[INFO] [15:53:04.915] Note that you will be able to access the updated dashboard once the server has processed the submitted analysis report.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 24.371s
[INFO] Finished at: Thu Sep 17 15:53:05 BST 2015
[INFO] Final Memory: 37M/896M
[INFO] ------------------------------------------------------------------------
I am not sure if I have missed something or something is not configured properly. Any ideas?
Thanks!

Answer 1

I have found the problem. For Java projects, the duplication detection mechanism behaves slightly differently as a piece of code is considered as duplicated as soon as there is the same sequence of 10 successive statements whatever is the number of tokens and lines. Therefore, I have managed to see the duplications after adding more duplicated loops in my Test class.