Java – How to set environment variable or system property in spring tests

environment-variablesjavaspringspring-test

I'd like to write some tests that check the XML Spring configuration of a deployed WAR. Unfortunately some beans require that some environment variables or system properties are set. How can I set an environment variable before the spring beans are initialized when using the convenient test style with @ContextConfiguration?

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:whereever/context.xml")
public class TestWarSpringContext { ... }

If I configure the application context with annotations, I don't see a hook where I can do something before the spring context is initialized.

Best Answer

You can initialize the System property in a static initializer:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:whereever/context.xml")
public class TestWarSpringContext {

    static {
        System.setProperty("myproperty", "foo");
    }

}

The static initializer code will be executed before the spring application context is initialized.

Related Solutions

Java – How to assert that a certain exception is thrown in JUnit 4 tests

It depends on the JUnit version and what assert libraries you use.

For JUnit5 and 4.13 see answer https://stackoverflow.com/a/2935935/2986984
If you use assertJ or google-truth, see answer https://stackoverflow.com/a/41019785/2986984

The original answer for JUnit <= 4.12 was:

@Test(expected = IndexOutOfBoundsException.class)
public void testIndexOutOfBoundsException() {

    ArrayList emptyList = new ArrayList();
    Object o = emptyList.get(0);

}

Though answer https://stackoverflow.com/a/31826781/2986984 has more options for JUnit <= 4.12.

Reference :

JUnit Test-FAQ

Spring beans redefinition in unit test environment

I would propose a custom TestClass and some easy rules for the locations of the spring bean.xml:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
    "classpath*:spring/*.xml",
    "classpath*:spring/persistence/*.xml",
    "classpath*:spring/mock/*.xml"})
@Transactional
@TestExecutionListeners({
    DependencyInjectionTestExecutionListener.class,
    TransactionalTestExecutionListener.class,
    DirtiesContextTestExecutionListener.class})
public abstract class AbstractHibernateTests implements ApplicationContextAware {

    /**
     * Logger for Subclasses.
     */
    protected final Logger log = LoggerFactory.getLogger(getClass());

    /**
     * The {@link ApplicationContext} that was injected into this test instance
     * via {@link #setApplicationContext(ApplicationContext)}.
     */
    protected ApplicationContext applicationContext;

    /**
     * Set the {@link ApplicationContext} to be used by this test instance,
     * provided via {@link ApplicationContextAware} semantics.
     */
    @Override
    public final void setApplicationContext(
            final ApplicationContext applicationContext) {
        this.applicationContext = applicationContext;
    }
}

If there are mock-bean.xml in the specified location, they will override all "real" bean.xml files in the "normal" locations - your normal locations might differ.

But … I would never mix mock and non-mock beans, as it's hard to trace problems when the application grows older.

Best Answer

Related Solutions

Java – How to assert that a certain exception is thrown in JUnit 4 tests

Spring beans redefinition in unit test environment

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