How do I mock an autowired @Value field in Spring with Mockito?

spring mockito autowired value-initialization
Dave picture Dave · Apr 18, 2014 · Viewed 143.3k times · Source

I'm using Spring 3.1.4.RELEASE and Mockito 1.9.5. In my Spring class I have:

@Value("#{myProps['default.url']}")
private String defaultUrl;

@Value("#{myProps['default.password']}")
private String defaultrPassword;

// ...

From my JUnit test, which I currently have set up like so:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({ "classpath:test-context.xml" })
public class MyTest 
{

I would like to mock a value for my "defaultUrl" field. Note that I don't want to mock values for the other fields — I'd like to keep those as they are, only the "defaultUrl" field. Also note that I have no explicit "setter" methods (e.g. setDefaultUrl) in my class and I don't want to create any just for the purposes of testing.

Given this, how can I mock a value for that one field?

Answer

geoand picture geoand · Apr 18, 2014

You can use the magic of Spring's ReflectionTestUtils.setField in order to avoid making any modifications whatsoever to your code.

The comment from Michał Stochmal provides an example:

use ReflectionTestUtils.setField(bean, "fieldName", "value"); before invoking your bean method during test.

Check out this tutorial for even more information, although you probably won't need it since the method is very easy to use

UPDATE

Since the introduction of Spring 4.2.RC1 it is now possible to set a static field without having to supply an instance of the class. See this part of the documentation and this commit.

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