Code: Config and properties

We will create a new properties file test.properties with active profile details:

spring.profiles.active=dbprofile

This will be used if we are not specifying a profile using @ActiveProfiles annotation.

Code: TestConfig.java

package com.javajee.spring;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
@PropertySource("classpath:/test.properties")
@ComponentScan(basePackages="com.javajee.spring")
public class TestConfig {

}

Code: JUNIT Test Classes

JJDatabaseWriterTest.java

package com.javajee.spring;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.javajee.spring.JJWriter;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { TestConfig.class })
@ActiveProfiles("dbprofile")
public class JJDatabaseWriterTest {

    @Autowired
    JJWriter jjwriter;
    
    @Test
    public void testJJDatabaseWriterToString()
    {
        Assert.assertEquals("Writing to Database!!!", jjwriter.toString());
    }
    
}

JJFileWriterTest.java

package com.javajee.spring;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.javajee.spring.JJWriter;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { TestConfig.class })
@ActiveProfiles("fileprofile")
public class JJFileWriterTest {

    @Autowired
    JJWriter jjwriter;
    
    @Test
    public void testJJDatabaseWriterToString()
    {
        Assert.assertEquals("Writing to File!!!", jjwriter.toString());
    }
    
}

JJWriterTest.java

This class is just to test the default scenario when no active profiles are specified, and might not be required in an actual use case.

package com.javajee.spring;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.javajee.spring.JJWriter;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { TestConfig.class })
public class JJWriterTest {

    @Autowired
    JJWriter jjwriter;
    
    @Test
    public void testJJDatabaseWriterToString()
    {
        Assert.assertEquals("Writing to Database!!!", jjwriter.toString());
    }
    
}

Executing Tests

You can now right click and run each of these tests as JUnit tests to see the results. Modify things and play around to see positive and negative cases.

Refactoring Test Classes

As you can see, below annotations are repeated across all test classes:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { TestConfig.class })

You can move any such repeated annotations to an appropriate parent class and then extend from it, but is not a requirement. 

MyAbstractSpringTest.java

package com.javajee.spring;

import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { TestConfig.class })
public class MyAbstractSpringTest {

}

Now I can change my test cases as: 

package com.javajee.spring;

import org.junit.Assert;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ActiveProfiles;

import com.javajee.spring.JJWriter;

@ActiveProfiles("dbprofile")
public class JJDatabaseWriterTest extends AbstractSpringTest{

    @Autowired
    JJWriter jjwriter;
    
    @Test
    public void testJJDatabaseWriterToString()
    {
        Assert.assertEquals("Writing to Database!!!", jjwriter.toString());
    }
    
}

Note that only additional annotations need to be specified. You can also change your config class for tests all at once.

I am not going into any debate on whether to do this or not, but wanted to show that this is possible.