java - Parallel JUnit tests don't execute shutdown hook -

i running multiple junit tests in parallel classes using maven. have clean tasks need happen after junit tests run. handle clean up, adding shut down hook few tests. shut down hook correctly executes when not running parallel, don't see output (see example) shut down hook when run parallel. there doing wrong? jvm exit using system.exit when executing in junit tests in parallel?

according surfire documentation documentation, parallel threads executed in same process, expect runtime.getruntime same process if called between different tests , threads. maven surfire plugin - fork options , parallel test execution

the important thing remember parallel option is: concurrency happens within same jvm process. efficient in terms of memory , execution time, may more vulnerable towards race conditions or other unexpected , hard reproduce behavior.

here example unit test:

@test public void test() {     runtime.getruntime().addshutdownhook(new thread()     {         @override         public void run()         {             system.out.println("test clean triggered");         }     }); } 

here relevant portion of pom:

<plugin>     <groupid>org.apache.maven.plugins</groupid>     <artifactid>maven-surefire-plugin</artifactid>     <version>2.18.1</version>     <configuration>         <parallel>classes</parallel>         <threadcount>10</threadcount>     </configuration> </plugin> 

edited: problem fixed when add shut down hook in @beforeclass method. when add in @test method, have problem. able add hook @ time.

your shutdown hooks called, issue believe comes system.out.println call associated shutdown hooks maven.

testing directly eclipse, have output:

test clean triggered 

and trying different version of test:

    @test     public void test()     {         system.out.println("testing");         runtime.getruntime().addshutdownhook(new thread()         {             @override             public void run()             {                 try {                                 files.createfile(paths.get("test1"));                             } catch (ioexception e) {                                 // todo auto-generated catch block                                 e.printstacktrace();                             }             }         });          asserttrue(true);        } 

i can see @ root of director file "test1" created after calling mvn clean test

tests made with:

• openjdk version "1.8.0_121"
• junit 4.12
• maven 3.3.9
• maven surefire-plugin 2.17