Spring Security - get User Name

If you want to retrieve the name of  a logged in user, do this:

import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;

private String getUserName() {

    Object principal = SecurityContextHolder
          .getContext()
          .getAuthentication()
          .getPrincipal();

    String userName;

    if (principal instanceof UserDetails) {
        userName = ((UserDetails)principal).getUsername();
    } else {
        userName = principal.toString();
    }
    return userName;
}

Recover and Restore System Properties with Java - JUnit and more - Free program

Sometimes it is necessary to change System Properties. Maybe for a Test or something else. This program and test will recover and restore the System Properties to their initial state.

The program and test may be used freely under GNU General Public License Version and is brought to you by Harder IT Consulting www.harder-it-consulting.de
  

Download here

Remove duplicates in list with Java > 8

    //remove duplicates from a list with Java 8 or greater     

    mylist.stream().distinct.collect(Collectors.toList())

Mock static methods with Mockito in Java (mock, static, method, java)

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.BDDMockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest(MyStatic.class)
...


@Test

public void someTest() {
    

    //given    

    PowerMockito.mockStatic(MyStatic.class);
    BDDMockito.given(MyStatic.someStaticMethod()).willReturn(...);

    //when
    ...

    //then     

    PowerMockito.verifyStatic();
    MyStatic.someStaticMethod();

    assertThat(//your further asserts....