write a simple junit4 test

Question

hello, I tried to write a simple junit test as follow :

@before
public void start(){
MyAppli.OpenResults();
}
@Test
public void test1(){
File.OpenFile();
}
@After
public void closeappli(){
MuAppli.close();
}

but when I run the junit test, it launched the appli then stop test without doing File.OpenFile(); and what is also done in @after

any idea? may I write something wrong? - How could I get error message generated by assert and display it in another file ?