CODEWITHSUNDEEP
javaspringunit-testing
anuta
anuta

Reputation: 11

Overriding default Spring @Value annotation value in unit test

I am trying to override Spring @Value annotated property that has a default value in the test class. 

@Configuration
public class MyConfig {
    @Value("${MAX_CONN:200}")
    private int maxConn;

    //more code here
}

@RunWith(SpringRunner.class)
@ContextConfiguration(classes={MyConfig.class, PropertySourcesPlaceholderConfigurer.class}, loader=AnnotationConfigContextLoader.class)
@TestPropertySource(properties = {
        "MAX_CONN=2"
})
public class SomeTest {
    //tests here
}

I'm using org.springframework.test.context.TestPropertySource annotation for the purpose (thanks for the advise). During the debug, I see that maxConn value is still 200. If the default value is removed from the original code @Value("${MAX_CONN}"), the maxConn value got overridden with 2. The default property can also be overridden by defining an environment variable. I wonder if there is a way to override the @Value annotated property that has a default value?

Note: Spring version - 4.3.13

Upvotes: 1

Views: 6216

Answers (2)

Mahendra Kapadne
Mahendra Kapadne

Reputation: 426

enter image description here

Output with above run configuration

MyConfig{maxConn=100}

Process finished with exit code 0

SpringBootWebApplication.java

package com.test;

import com.test.service.MyConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.Banner;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootConsoleApplication implements CommandLineRunner {

    @Autowired
    MyConfig myConfig;


    public static void main(String[] args) throws Exception {
        SpringApplication app = new SpringApplication(SpringBootConsoleApplication.class);
        app.setBannerMode(Banner.Mode.OFF);
        app.run(args);
        //SpringApplication.run(SpringBootConsoleApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        System.out.println(myConfig);
    }
}

MyConfig.java

package com.test.service;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class MyConfig {

    @Value("${MAX.CONN:200}")
    private int maxConn;

    @Override
    public String toString() {
        return "MyConfig{" +
                "maxConn=" + maxConn +
                '}';
    }
}

TestProperties.java

import com.test.SpringBootConsoleApplication;
import com.test.service.MyConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = SpringBootConsoleApplication.class)
public class TestProperties {

    static {
        System.setProperty("MAX.CONN", "2");
    }

    @Autowired
    MyConfig myConfig;

    @Test
    public void testSequence() {
        //System.out.println(myConfig);
        //...
    }

}

Output with Test:

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.9.RELEASE)

MyConfig{maxConn=2}

Process finished with exit code 0

Upvotes: 1

surya
surya

Reputation: 2749

For using properties in unit test cases, conventionally there are two ways,

1> You should have your own set of properties used for testing and file should be under your classpath (/src/test/resources ).

@PropertySource("classpath:application-test.properties ")

2> Another convention is to have property files with the same name on different classpaths. You load one or the other depending on whether you are running your tests or not.

Thus in a typically laid out application, it is:

src/test/resources/application.properties

and

src/main/resources/application.properties

and use it as

@PropertySource("classpath:application.properties ")

Upvotes: 0

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