Cannot #Autowire configuration - java

I am absolutely new to TestNG, Spring framework etc. and I'm trying to use the annotation #Value access to configuration file via the #Configuration annotation.
All I'm trying to achieve here is to make the console write out "hi" from the config file accessing the value via #Value. I must be obviously missing the whole point of the #Value annotation (or #Autowired or some other annotations) as all I'm gettting is java.lang.NullPointerException.
I have the following three files (reduced to the absolute minimum):
config.properties
a="hi"
TestConfiguration.java
#Configuration
#PropertySource("config.properties")
public class TestConfiguration {
#Value("${a}")
public String A;
}
TrialTest.java
public class TrialTest {
#Autowired
private TestConfiguration testConfiguration;
#Test
public void test() {
System.out.println(testConfiguration.A);
}
}
Thanks a lot.

Try annotate your test class with these:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes={TestConfiguration.class})
[Edit] sorry I didn't see that OP was using TestNG. The essential point is still that the problem is caused by Spring not being bootstrapped. In TestNG that can be done via extending AbstractTestNGSpringContextTests.

Make sure that in your config, you are declaring the PropertySourcesPlaceholderConfigurer bean which can resolve the #Value expressions. Declare this bean:
#Configuration
#PropertySource("config.properties")
public class TestConfiguration {
#Value("${a}")
public String A;
#Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer()
{
return new PropertySourcesPlaceholderConfigurer();
}
}
Note that you do not have to do anything with this bean, just by declaring it, it will allow the #Value annotation expressions to work as expected.
You can either redundantly declare this bean in every class that uses a #Value annotation, but that would be bad practice/style as it would keep overwriting the bean in each new declaration. Instead, place this bean at the top most config which imports other configs using #Value and you can recycle the PropertySourcesPlaceholderConfigurer bean from the one place.

Related

Spring boot test with multiple configuration

In my Spring boot 2.1 project I have different #Configurations for different test (ConfigurationA and ConfigurationB), that reside in different packages. Both configurations define the same set of beans but in a different manner (mocked vs. the real thing)
As I am aware of the Bean overriding mechanism introduced in Spring Boot 2.1, I have set the property: spring.main.allow-bean-definition-overriding=true.
However I do have a test with the following the setup of the following configuration and test class. First there is a #Configuration in the productive part (I'm using Maven):
package com.stackoverflow;
#Configuration
public class ProdConfiguration{
...
}
Then in the test branch there is a general Test #Configuration on the same package level:
package com.stackoverflow
#Configuration
public class TestConfiguration {
#Bean
public GameMap gameMap() {
return Mockito.mock(GameMap.class);
}
}
And in a subpackage I have another #Configuration:
package com.stackoverflow.impl;
#Configuration
public class RealMapTestConfiguration {
#Bean
public GameMap gameMap() {
return new GameMap("testMap.json");
}
}
And then of course there is the test that is troubling me:
package com.stackoverflow.impl;
#ExtendWith(SpringExtension.class)
#SpringBootTest
#ContextConfiguration(classes={RealMapTestConfiguration.class, ProdConfiguration.class})
#ActiveProfiles("bug") // spring.main.allow-bean-definition-overriding=true
public class MapImageServiceIT {
#Autowired
private GameMap map;
}
It turns out that the injected GameMap into my test is a mock instance from TestConfiguration instead of the real thing from RealMapTestConfiguration. Aparrently in my test I have the configuration from ProdConfiguration and TestConfiguration, when I wanted ProdConfiguration and RealMapTestConfiguration. As the beans defined in the ProdConfiguration and *TestConfiguration are different the combination works, but TestConfiguration and RealMapTestConfiguration define the same been. It seems like the TestConfiguration is picked up by component scanning as it is in the same package as ProdConfiguration.
I was under the impression that when overriding beans the bean definition that is closer to the test class would be preferred. However this seems not to be the case.
So here are my questions:
When overriding beans, what is the order? Which bean overrides which one?
How to go about to get the correct instance in my test (using a different bean name is not an option, as in reality the injected bean is not directly used in the test but in a service the test uses and there is no qualifier on it.)
I've not used the spring.main.allow-bean-definition-overriding=true property, but specifying specific config in a test class has worked fine for me as a way of switching between objects in different tests.
You say...
It turns out that the injected GameMap into my test is a mock instance from TestConfiguration instead of the real thing from RealMapTestConfiguration.
But RealMapTestConfiguration does return a mock
package com.stackoverflow.impl;
#Configuration
public class RealMapTestConfiguration {
#Bean
public GameMap gameMap() {
return Mockito.mock(GameMap.class);
}
}
I think the problem here is that including ContextConfiguration nullifies (part of) the effect of #SpringBootTest. #SpringBootTest has the effect of looking for #SpringBootConfiguration in your application (starting from the same package, I believe). However, if ContextConfiguration is applied, then configurations are loaded from there.
Another way of saying that: because you have ContextConfiguration in your test, scanning for #Configuration classes is disabled, and TestConfiguration is not loaded.
I don't think I have a full picture of your configuration setup so can't really recommend a best practice here, but a quick way to fix this is to add TestConfiguration to your ContextConfiguration in your test. Make sure you add it last, so that it overrides the bean definitions in the other two configurations.
The other thing that might work is removing #ContextConfiguration entirely and letting the SpringBootApplication scanning do its thing - that's where what you said about the bean definition that is closest may apply.
In that case just don't use #Configuration on configuration class and import it to the test manually using #Import, example:
#SpringBootTest
#Import(MyTest.MyTestConfig.class)
public class MyTest {
#Autowired
private String string;
#Test
public void myTest() {
System.out.println(string);
}
static class MyTestConfig {
#Bean
public String string() {
return "String";
}
}
}

Spring Boot: #TestConfiguration Not Overriding Bean During Integration Test

I have a Bean defined in a class decorated with #Configuration:
#Configuration
public class MyBeanConfig {
#Bean
public String configPath() {
return "../production/environment/path";
}
}
I have a class decorated with #TestConfiguration that should override this Bean:
#TestConfiguration
public class MyTestConfiguration {
#Bean
#Primary
public String configPath() {
return "/test/environment/path";
}
}
The configPath bean is used to set the path to an external file containing a registration code that must be read during startup. It is used in an #Component class:
#Component
public class MyParsingComponent {
private String CONFIG_PATH;
#Autowired
public void setCONFIG_PATH(String configPath) {
this.CONFIG_PATH = configPath;
}
}
While trying to debug this I set a breakpoint inside each method as well as the constructor of the test config class. The #TestConfiguration's constructor breakpoint is hit, so i know that my test configuration class instantiates, however the configPath method of that class is never hit. Instead, the configPath method of the normal #Configuration class is hit and the #Autowired String in MyParsingComponent is always ../production/environment/path rather than the expected /test/environment/path.
Not sure why this is happening. Any thoughts would be greatly appreciated.
As documented in the Detecting Test Configuration section of the Spring Boot reference manual, any beans configured in a top-level class annotated with #TestConfiguration will not be picked up via component scanning. So you have to explicitly register your #TestConfiguration class.
You can do that either via #Import(MyTestConfiguration.class) or #ContextConfiguration(classes = MyTestConfiguration.class) on your test class.
On the other hand, if your class annotated with #TestConfiguration were a static nested class within your test class, it would be registered automatically.
Make sure that the method name of your #Bean factory method does not match any existing bean name. I had issues with method names like config() or (in my case)
prometheusConfig() which collided with existing bean names. Spring skips those factory methods silently and simply does not call them / does not instantiate the beans.
If you want to override a bean definition in your test, use the bean name explicitly as string parameter in your #Bean("beanName") annotation.
Test configuration has to be explicitly imported in the test via #Import({MyTestConfiguration.class}).
The name of the #Bean methods in #Configuration and #TestConfiguration have to be different. At least it makes difference in Spring Boot v2.2.
Also make sure spring.main.allow-bean-definition-overriding=true otherwise the bean could not be overriden.
For me worked this code:
#TestConfiguration // 1. necessary
public class TestMessagesConfig {
#Bean
#Primary // 2. necessary
public MessageSource testMessageSource() { // 3. different method name than in production code e.g. add test prefix
}
}
I struggled with a related problem, whereby even though I was using an inner static class, my test bean was not being registered.
It turns out, You still need to add your inner static class to the #ContextConfiguration class array, otherwise the beans inside the #TestConfiguration doesn't get picked up.
public interface Foo {
String execute();
}
public class FooService {
private final Foo foo;
FooService(Foo foo) {
this.foo = foo;
}
public String execute() {
return foo.execute();
}
}
#ExtendWith(SpringExtension.class)
#ContextConfiguration(classes = {FooService.class, FooTest.FooTestConfig.class})
public class FooTest {
#Autowired
FooService fooService;
#Test
void test() {
Assertions.assertEquals("MY_TEST_BEAN", fooService.execute());
}
#TestConfiguration
static class FooTestConfig {
#Bean
public Foo getFooBean() {
return () -> "MY_TEST_BEAN";
}
}
}
I came across a similar issue recently and got it sorted out by annotating my testing bean with #Primary as well as #Bean. Not sure why it's required, which seems not documented in the Spring doc. The version of my SpringBoot is 2.0.3.
In my case it was an issue with #RunWith(SpringRunner.class), I'm not exactly sure why it wasn't working, I was following this - Testing in Spring Boot
But after replacing that with #ExtendWith(SpringExtension.class) the inner static #TestConfiguration class created the beans as expected.
Maybe a version mismatch - I'm using Spring Boot 2.7.2.
In my case replacing #Import(TestConfig.class) with #ContextConfiguration(classes=TestConfig.class) did the trick. For some reason, some of the beans from TestConfig but 1 wasn't until I replaced #Import with #ContextConfiguration.
This was also mentioned in some comments that were hidden because they had no upvotes.
I found it odd how several answers stated that the names of the #Beans have to be different from each other. How would that make one override the other?
There wasn't one specific answer that worked for me, but I've solved the issue by combining some of their advices.
Here's what worked for me.
Main configuration class:
#Configuration
public class SpringConfiguration {
#Bean
BeanInterface myBean() {
return new BeanImplementation();
}
#Bean
OtherClass otherBean() {
return new OtherClass();
}
}
Test configuration class:
#TestConfiguration
public class TestSpringConfiguration {
#Bean
#Primary
BeanInterface myBean() {
return new TestBeanImplementation();
}
}
Test class:
#SpringBootTest(classes = TestSpringConfiguration.class,
properties = "spring.main.allow-bean-definition-overriding=true")
public class Tests {
#Test
public void test() {
// do stuff
}
}
In this way, the "myBean" bean instance is the one defined in the TestSpringConfiguration class, while "otherBean" is the one defined in the SpringConfiguration class, since it's not overridden.
If I gave two different names to the "myBean" beans, the "real" one would still be initialized and, in my case, would give an error during tests, since it needs something that's only available at runtime in its proper environment.
Once I gave both the same name, Spring would throw an error saying that they were conflicting. Hence why I had to specify the property spring.main.allow-bean-definition-overriding=true in the #SpringBootTest annotation of the test class.
By the way, if you're NOT using Spring Boot, I guess these alternative annotations could work for you:
#ExtendWith(value = SpringExtension.class)
#ContextConfiguration(loader = AnnotationConfigContextLoader.class, // <- not sure about this one
classes = { SpringConfiguration.class, TestSpringConfiguration.class })
public class Tests {
#Test
public void test() {
// do stuff
}
}
Then, you would still have to set the property spring.main.allow-bean-definition-overriding=true in the test application.yml or application.properties file, or in some other way via code on startup.
Note: I'm not 100% sure that you would need the loader = AnnotationConfigContextLoader.class thing. Try without it, first. I needed it in a project of mine which had Spring without Boot, but I can't remember whether it's a standard thing to set or I needed it for some specific reason.

What difference does #EnableConfigurationProperties make if a bean is already annotated with #ConfigurationProperties?

The Spring Boot documentation says that to use the #ConfigurationProperties annotation
You also need to list the properties classes to register in the
#EnableConfigurationProperties annotation, as shown in the following
example:
and gives this code:
#Configuration
#EnableConfigurationProperties(AcmeProperties.class)
public class MyConfiguration {
}
But in the very next paragraph says:
Even if the preceding configuration creates a regular bean for
AcmeProperties, we recommend that #ConfigurationProperties only deal
with the environment and, in particular, does not inject other beans
from the context. Having said that, the #EnableConfigurationProperties
annotation is also automatically applied to your project so that any
existing bean annotated with #ConfigurationProperties is configured
from the Environment.
Suggesting that listing a #ConfigurationProperties bean under an #EnableConfigurationProperties annotation is not necessary.
So which is it? Experimentally, I've seen that if I annotate a bean with #ConfigurationProperties it gets properties injected to it as expected without needing to list it in #EnableConfigurationProperties, but if this is the case then why list anything that has a #ConfigurationProperties annotation under #EnableConfigurationProperties, as is shown in the documentation? Does it make any kind of difference?
As M. Deinum referred #EnableConfigurationProperties Is for enabling support of #ConfigurationProperties. If you take a look to the annotation Java Doc you can see:
Enable support for ConfigurationProperties annotated beans. ConfigurationProperties beans can be registered in the standard way (for example using Bean #Bean methods) or, for convenience, can be specified directly on this annotation. [...]
For example, let's say you have a class whose responsibility is to read and store information from your application.yml / application.properties that is required to make a connection to different databases. You annotate it with #ConfigurationProperties.
Then, you typically have a #Configuration annotated class that provides a DataSource #Bean to your application. You can use the #EnableConfigurationProperties to link it to the #ConfigurationProperties class and init your data sources accordingly.
Here is a small example:
application.yml
data-sources:
db1:
url: "jdbc:postgresql://localhost:5432}/db1"
username: test
password: test
db2:
url: "jdbc:postgresql://localhost:5432}/db2"
username: test
password: test
DataSourcesConfiguration
#ConfigurationProperties
public class DataSourcesConfiguration {
private Map<String, BasicDataSource> dataSources;
public void setDataSources(Map<String, BasicDataSource> dataSources) {
this.dataSources = dataSources;
}
Map<String, BasicDataSource > getDataSources() {
return dataSources;
}
}
DataSourceConnectionConfiguration
#Configuration
#EnableConfigurationProperties(DataSourcesConfiguration.class)
public class DatabaseConnectionConfiguration implements Provider<Connection> {
private DataSourcesConfiguration dataSourcesConfiguration;
public DatabaseConnectionConfiguration(DataSourcesConfiguration dataSourcesConfiguration) {
this.dataSourcesConfiguration = dataSourcesConfiguration;
}
#Bean
public DataSource dataSource() {
// Use dataSourcesConfiguration to create application data source. E.g., a AbstractRoutingDataSource..
}
}
It took me a while to reach to this post but would like to add here so that others may get benefited.
#ConfigurationProperties - Used to bind a class with an externalized property file. Very powerful and must be used to separate out bean classes with configuration entity class.
#Configuration - Creates a Spring bean of configuration stereotype.
#EnableConfigurationProperties - Creates a binding between a configuration entity class and Spring configuration stereotype so that after injection within a service properties can be retrieved easily.
If we look at the code below:
#Configuration #EnableConfigurationProperties #ConfigurationProperties(prefix="ar1")
public class ar1Settings { }
#Configuration tells Spring to treat this as a configuration class and register it as a Bean
#EnableConfigurationProperties tells Spring to treat this class as a consumer of application.yml/properties values
#ConfigurationProperties tells Spring what section this class represents.
My understanding is that if you don't need to specify the section of the property file, then #ConfigurationProperties can be omitted.
#EnableConfigurationProperties imports EnableConfigurationPropertiesRegistrar which enables support for #ConfigurationProperties annotated beans.
#ConfigurationProperties is an annotation for externalized configuration, it is to be applied to a bean configuration class or method annotated with #Bean eg
#ConfigurationProperties(prefix = "some-prefix")
public SomePrefix prefixBean() {
return new SomePrefix();
}
To load the properties and bind them to properties within the method or the class that match the prefix.
ps: some-prefix binds to SomePrefix because of spring's support for Relaxed binding.
Before springboot 2.2, You could do either of the following:
#Configuration
#ConfigurationProperties(prefix = "some-prefix")
public class ConfigProperties {
//...some code
}
or
#Configuration
#EnableConfigurationProperties(SomeClassToBeBounded.class)
public class ConfigProperties {
along with
#ConfigurationProperties(prefix = "some-prefix")
public class SomeClassToBeBounded{
//...some code
}
From springboot 2.2
You can do it in a much easier way:
#ConfigurationProperties(prefix = "some-prefix")
#ConfigurationPropertiesScan
public class ConfigProperties {
//...some code
}
With this, the classpath scanner enabled by #SpringBootApplication finds the ConfigProperties class, even though we didn't annotate this class with #Component.

#refreshScope and #PropertySource how to?

Anybody know if #RefreshScope, applied to class for reloading properties/yml files dinamically works with a configuration class annotated only with #PropertySource?
I have to refresh an external configuration file, but i cant do something like :
#Bean
#RefreshScope
public FileProperties refreshListConfig() {
return new FileProperties(); //why ?
}
#Configuration //Configuration or new instance as above?
#PropertySource("file:${path.properties}")
#ConfigurationProperties(prefix="multitenancy")
public class FileProperties {
private List<DirProps> dir =new ArrayList<DirProps>();
private String tenantsFilePath;
..
class DirProps { ..}
...
}
I know that #RefreshScope doesn't work with #Configuration, but can I use #PropertySource without #Configuration?
Javadoc :
Annotation providing a convenient and declarative mechanism for adding a PropertySource to Spring's Environment. To be used in conjunction with #Configuration classes.
So, can't i use #RefreshScope without move external properties in application properties and removing #PropertySource and #Configuration annotations from FileProperties class? Do you know if exists a working approach without move the properties?
Thanks

What are all the #Configuration naming rules for beans?

I have some integration tests that are supposed to mock out one of many beans in my system. To do this, I have a #Configuration that looks like this:
#Configuration
public class MockContext {
#Primary
#Bean
public RealBean realBean() {
return new MockBean();
}
}
I noticed that this method gets used if RealBean is a java class without #Component. But if RealBean is a #Component, I have to change this context method to look like this:
#Configuration
public class MockContext {
#Primary
#Bean
public RealBean getRealBean() {
return new MockBean();
}
}
Can anyone explain why I need to change this method name and where I can find all these rules? It takes a very long time to troubleshoot these "why isn't my MockContext working correctly?" issues.
FWIW, here's how I'm using this context in a test:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = {RealContext.class, MockContext.class})
#WebAppConfiguration
public abstract class AbstractIntegrationTest {
And my integration test will extend this class. I am using Spring Boot 1.2.4.RELEASE
You can have various beans registered with same type. But they need to have different names.
If you use #Bean annotation without name attribute, name of the bean is extracted from method name (in your case realBean/getRealBean).
When you use #Component annotation without attribute (which specifies bean name), name of the bean is extracted from method name where first letter is lowercased.
So with your first case, you get a name clash. You can't have two beans named realBean.
Your second example is without clash because bean annotated by #Component has name realBean and second bean registered via #Bean has name getRealBean.
#Primary annotation helps Spring choose which bean to pick if there are two of the same type and you inject by type. When you inject by name (usage of #Qualifier annotation), you can inject also secondary instance.

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