Using actual properties file from src/main/resources with Spring @PropertySource in JUnit test

Question

I am trying to unit test a DAO class by using a H2 database instead of an actual database. I am facing an issue while trying to make my test case use a properties file that is present in the src/main/resources/properties/ folder:

Test class

@RunWith(SpringJUnit4ClassRunner.class)
@PropertySource("classpath:properties/common.properties")
@ContextConfiguration(locations = { "/spring/common-context.xml" })
public class ConfigDAOImplTest {

    @Autowired
    private ConfigDAOImpl configDAO;

    @Spy
    private ContextParamDAO contextParamDAO = new ContextParamDAOImpl();

    private static final String SCHEMA_CONFIG = "classpath:data/CONFIG_SCHEMA.sql";
    private static final String DATA_CONFIG = "classpath:data/CONFIG_DATA.sql";

    @Before
    public void init() {
        MockitoAnnotations.initMocks(this);

        DataSource dataSource = new EmbeddedDatabaseBuilder()
                .setType(EmbeddedDatabaseType.H2)
                .addScript(SCHEMA_CONFIG)
                .addScript(DATA_CONFIG)
                .build();

        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        //override the jdbcTemplate for the test case    
        configDAO.setJdbcTemplate(jdbcTemplate);
        configDAO.setContextParamDAO(contextParamDAO);


    }

    //.. more coode
}

common-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:batch="http://www.springframework.org/schema/batch"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd        
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-2.5.xsd      
        http://www.springframework.org/schema/batch 
        http://www.springframework.org/schema/batch/spring-batch.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

    <bean id="commonAppProperties"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="ignoreResourceNotFound" value="true" />
        <property name="ignoreUnresolvablePlaceholders" value="true" />
        <property name="locations">
            <list>
                <value>file:${conf_folder_path}/common.properties</value>
            </list>
        </property>
    </bean>

    <bean id="configDAO"
        class="com.myproject.common.dataaccess.impl.ConfigDAOImpl" scope="step">
        <property name="jdbcTemplate" ref="jdbcTemplate" />
        <property name="corePoolSize" value="${threadpool.size}"/>
    </bean>
</beans>

When I run the test class, I get the following exception:

Caused by: org.springframework.beans.TypeMismatchException: Failed to convert property value of type 'java.lang.String' to required type 'int' for property 'corePoolSize'; nested exception is java.lang.NumberFormatException: For input string: "${threadpool.size}"

One reason for the test case not being able to find the required property is because:

1. The PropertyPlaceholderConfigurer bean refers to {conf_folder_path}/common.properties which is the path where src/main/resources/properties/common.properties gets copied to by Maven build system.
2. However, in Eclipse, there is no {conf_folder_path} as this is created by Maven.

Question: Assumnig that the above reason is the root cause of the issue, how do I make the test case find the properties considering the path refereed to in the Spring context is different from that in the source code.

Answer 1

You can create something like this:

@Configuration
public class TestConfiguration {

    private static final Logger log = LoggerFactory.getLogger(TestConfiguration.class);

    @Autowired
    private Environment env;

    /**
     * This bean is necessary in order to use property file from src/main/resources/properties
     * @param env environment
     * @return property source configurator with correct property file
     */
    @Bean
    public PropertySourcesPlaceholderConfigurer placeholderConfigurerDev(ConfigurableEnvironment env) {
        final String fileName = "common.properties";
        Path resourceDirectory = Paths.get("src","main","resources", "properties");
        String absolutePath = resourceDirectory.toFile().getAbsolutePath();
        final File file = new File(absolutePath.concat("/").concat(fileName));
        if (file.exists()) {
            try {
                MutablePropertySources sources = env.getPropertySources();
                sources.addFirst(new PropertiesPropertySource(fileName, PropertiesLoaderUtils.loadAllProperties(file.getName())));
            } catch (Exception ex) {
                log.error(ex.getMessage(), ex);
                throw new RuntimeException(ex.getMessage(), ex);
            }
        }
        this.env = env;
        return new PropertySourcesPlaceholderConfigurer();
    }

Answer 2

Thanks to @Lemmy for the direction on how to solve this issue.

My final solution was to create a new common-test-context.xml file where I can look for the property file in the properties folder on the class path. I placed this file in src/test/resources/spring folder and imported the actual common-context.xml from src/main/resources/spring folder into it.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:batch="http://www.springframework.org/schema/batch"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd        
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-2.5.xsd      
        http://www.springframework.org/schema/batch 
        http://www.springframework.org/schema/batch/spring-batch.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

    <import resource="classpath*:/spring/common-context.xml" />


    <bean id="commonAppProperties"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="ignoreResourceNotFound" value="true" />
        <property name="ignoreUnresolvablePlaceholders" value="true" />
        <property name="locations">
            <list>
                <value>classpath:/properties/common.properties</value>
            </list>
        </property>
    </bean>

</beans>