Cake Pattern and Spring Configurer - spring

Spring provides utility Configurer to resolve placeholders with external configuration data (see the documentation for details). How can I configure my components in a similar way (that is, using external configuration to resolve placeholders) with Cake Pattern?
For example:
// properties configuration file
driver=com.mysql.jdbc.Driver
dbname=mysql:mydb
user=michael
password=*****
trait JdbcSupport {
val dataSource:Datasource
...
}
trait OrderDAOComponent {self: JdbcSupport =>
val dao: OrderDAO
class OrderDAOImpl extends OrderDAO {...} // use the JDBC data source here
}
How can I use the properties configuration file to initialize the OrderDAO using the Cake Pattern?

trait XmlConfigJdbcSupport extends JdbcSupport {
val xmlFile:String
override val dataSource = readConfigAndReturnDatasource()
}
object MyContext extends OrderDAOComponent with XmlConfigJdbcSupport {
override val xmlFile = "config.xml"
}
dataSource should probably be a lazy val to avoid problems with the initialization order.

Related

#Value annotation unable to read properties file in spring boot camel application

I have a spring-boot application where I read data from queue and send data to transformation class using .bean()
Integration.java
class Integration {
#Value("${someURL}")
private String someURL; //able to read someURL from property file
from("queue")
// some intermediate code
.bean(new TransformationClass(), "transformationMethod")
// other code
}
Now, Inside TransformationClass I have #Value annotation to read values from properties file but it always returns a null.
TransformationClass.java
#Component
class TransformationClass {
#Value("${someURL}")
private String someURL; //someURL return null though there is key-value associated in props file.
public void transformationMethod(Exchange exchange) {
// other stuff related to someURL
}
}
Note - I am able to read values from property file in class Integration.java but unable to read from class TransformationClass.java
I am using spring boot version - 2.7.2 and camel version - 3.18.1 jdk - 17
I tried to read using camel PropertiesComponent but it did not worked.
Problem here is, that new TransformationClass() is not a "spring managed instance", thus all #Autowire/Value/Inject/...s have no effect.
Since TransformationClass is (singleton, spring-managed) #Component and is needed by Integration, wiring these makes sense:
Via field... :
class Integration {
#Autowired
private TransformationClass trnsObject;
// ...
Or constructor injection:
class Integration {
private final TransformationClass trnsObject;
public Integration(/*im- /explicitely #Autowired*/ TransformationClass pTrnsObject) {
trnsObject = pTrnsObject;
}
// ...
// then:
doSomethingWith(trnsObject); // has correct #Values
}

How to test #ConfigurationProperties with ApplicationContextRunner from spring-boot-test?

I need to test my autoconfiguration classes that make use of #ConfigurationProperties beans. I'm making use of ApplicationContextRunner as documented in https://docs.spring.io/spring-boot/docs/current/reference/html/spring-boot-features.html#boot-features-test-autoconfig to make tests faster and avoid starting the servlet container between each variations. However, beans annotated with #AutoconfigurationProperties are not populated with values injected into ApplicationContextRunner.
I suspect that I'm hitting problem similar to https://stackoverflow.com/a/56023100/1484823
#ConfigurationProperties are not managed by the application context you build in tests, although they will be load when the application launches, because you have #EnableConfigurationProperties on your app main class.
How can I enable support for #ConfigurationProperties with ApplicationContextRunner ?
Here is the corresponding code
#Test
void ServiceDefinitionMapperPropertiesAreProperlyLoaded() {
ApplicationContextRunner contextRunner = new ApplicationContextRunner()
.withConfiguration(AutoConfigurations.of(
SingleServiceDefinitionAnswerAutoConfig.class,
DynamicCatalogServiceAutoConfiguration.class
))
// .withPropertyValues(DynamicCatalogProperties.OPT_IN_PROPERTY + "=true") //Not sure why this seems ignored
.withSystemProperties(DynamicCatalogConstants.OPT_IN_PROPERTY + "=true",
ServiceDefinitionMapperProperties.PROPERTY_PREFIX
+ServiceDefinitionMapperProperties.SUFFIX_PROPERTY_KEY+ "=suffix")
;
contextRunner.run(context -> {
assertThat(context).hasSingleBean(ServiceDefinitionMapperProperties.class);
ServiceDefinitionMapperProperties serviceDefinitionMapperProperties
= context.getBean(ServiceDefinitionMapperProperties.class);
assertThat(serviceDefinitionMapperProperties.getSuffix()).isEqualTo("suffix");
});
}
which fails with:
org.opentest4j.AssertionFailedError:
Expecting:
<"">
to be equal to:
<"suffix">
but was not.
Expected :suffix
Actual :
<Click to see difference>
at org.springframework.cloud.appbroker.autoconfigure.DynamicCatalogServiceAutoConfigurationTest
public class DynamicCatalogServiceAutoConfiguration {
[...]
#Bean
#ConfigurationProperties(prefix=ServiceDefinitionMapperProperties.PROPERTY_PREFIX, ignoreUnknownFields = false)
public ServiceDefinitionMapperProperties serviceDefinitionMapperProperties() {
return new ServiceDefinitionMapperProperties();
}
[...]
}
Full sources available at https://github.com/orange-cloudfoundry/osb-cmdb-spike/blob/0da641e5f2f811f48b0676a25c8cbe97895168d1/spring-cloud-app-broker-autoconfigure/src/test/java/org/springframework/cloud/appbroker/autoconfigure/DynamicCatalogServiceAutoConfigurationTest.java#L89-L107
ps: I was about to submit an issue to https://github.com/spring-projects/spring-boot/issues to suggest documentation enhancement to warn of such limitation in ApplicationContext, and to ask for ways to turn on support for #ConfigurationProperties. Following guidance at https://raw.githubusercontent.com/spring-projects/spring-boot/master/.github/ISSUE_TEMPLATE.md, I'm first making sure here I'm not misunderstanding the problem.
If you want to populate a bean annotated with #ConfigurationProperties class as part of your test, and you normally depend on a configuration class annotated with #EnableConfigurationProperties to populate that bean, then you can create a trivial configuration class just for the test:
#ConfigurationProperties("app")
public class ConfigProps {
private int meaningOfLife;
public int getMeaningOfLife() { return meaningOfLife; }
public void setMeaningOfLife(int meaning) { this.meaningOfLife = meaning; }
}
class ConfigPropsTest {
private final ApplicationContextRunner runner = new ApplicationContextRunner();
#EnableConfigurationProperties(ConfigProps.class)
static class TrivialConfiguration {
}
#Test
void test() {
runner.withUserConfiguration(TrivialConfiguration.class)
.withPropertyValues("app.meaning-of-life=42")
.run(context -> {
assertEquals(42, context.getBean(ConfigProps.class).getMeaningOfLife());
});
}
}
Passing TrivialConfiguration to the ApplicationContextRunner is sufficient to make it create ConfigProps and populate it using the available properties.
As far as I can tell, none of the classes involved in your test enable configuration property binding. As a result, no properties are bound to ServiceDefinitionMapperProperties. You can enable configuration property binding using #EnableConfigurationProperties. A typical place to add it would be on DynamicCatalogServiceAutoConfiguration as its serviceDefinitionMapperProperties bean relies on configuration properties being enabled.

Spring Data Key Value Implementation for Oracle KV

I would like to use Oracle NoSQL database together with Spring data. The aim is to access the data over spring data repositories and even use spring data rest on top of it.
So I think the spring-data-keyvalue project would help me, to implement an adapter for Oracle NoSQL KV.
I tried to understand the documentation of spring-data-keyvalue (http://docs.spring.io/spring-data/keyvalue/docs/current/reference/html/#key-value.core-concepts), but didn't get the idea.
An example/tutorial about how to implement an adapter from scratch would be very helpful.
What I have is this configuration class where I provide a custom KeyValueAdapter. Now if I use CrudRepository methods it uses my custom adapter.
#Configuration
#EnableMapRepositories
public class KeyValueConfig {
#Bean
public KeyValueOperations keyValueTemplate() {
return new KeyValueTemplate(new OracleKeyValueAdapter());
}
}
The OracleKeyValueAdapter is an implementation of KeyValueAdapter. I got this from the spring-data-keyvalue-redis project (https://github.com/christophstrobl/spring-data-keyvalue-redis/blob/master/src/main/java/org/springframework/data/keyvalue/redis/RedisKeyValueAdapter.java)
public class OracleKeyValueAdapter extends AbstractKeyValueAdapter {
private KVStore store;
public OracleKeyValueAdapter() {
String storeName = "kvstore";
String hostName = "localhost";
String hostPort = "5000";
store = KVStoreFactory.getStore
(new KVStoreConfig(storeName, hostName + ":" + hostPort));
}
//Custom implementations:
#Override
public Object put(Serializable serializable, Object o, Serializable
serializable1) {
return null;
}
#Override
public boolean contains(Serializable serializable, Serializable
serializable1) {
return false;
}
.
.
.
Now I'm trying to implement this OracleKeyValueAdapter, but i don't know if that does even make sense.
Can you help me?
You might want to start with how spring-data-keyvalue is implemented over Redis, the link here should be a good starting point - http://docs.spring.io/spring-data/data-keyvalue/docs/1.0.0.BUILD-SNAPSHOT/reference/redis.html
Let me know how that goes, I am interested in what you are trying to accomplish.
The following configuration should work (tested on v2.4.3)
#Configuration
#EnableMapRepositories
public class Configuration {
#Bean
public KeyValueOperations mapKeyValueTemplate() {
return new KeyValueTemplate(keyValueAdapter());
}
#Bean
public KeyValueAdapter keyValueAdapter() {
return new YourKeyValueAdapter();
}
}
The name (mapKeyValueTemplate) of the KeyValueOperations bean is important here but it can also be changed as followed:
#Configuration
#EnableMapRepositories(keyValueTemplateRef = "foo")
public class Configuration {
#Bean
public KeyValueOperations foo() {
return new KeyValueTemplate(keyValueAdapter());
}
#Bean
public KeyValueAdapter keyValueAdapter() {
return new YourKeyValueAdapter();
}
}
I saw sources of Spring KeyValue Repository:
https://github.com/spring-projects/spring-data-keyvalue
I recomend to understand, how Spring Repository work inside.
If you want to realise own repository (CustomKeyValueRepository), you must create at least 6 classes:
EnableCustomKeyValueRepositories - annotation to enable repository type in your project.
CustomKeyValueRepositoriesRegistrar - registrator for this annotaion.
CustomKeyValueRepository - repository
CustomKeyValueRepositoryConfigurationExtension - implementation of Spring ConfigurationExtension.
CustomKeyValueAdapter - implementation of custom adapter for your data store.
CustomKeyValueConfiguration - configuration of beans Adapter and Template.
I code Infinispan KeyValue Repository by this way:
https://github.com/OsokinAlexander/infinispan-spring-repository
I also write article about this:
https://habr.com/ru/post/535218/
In Chrome you can translate it to your language.
The simplest way you can try implement only CustomKeyValueAdapter and Configuration. In Configuration you must redefine Spring KeyValueAdapter bean and KeyValueTemplate (it is very important that the name of the bean is with a lowercase letter, that's the only way it worked for me):
#Configuration
public class CustomKeyValueConfiguration extends CachingConfigurerSupport {
#Autowired
private ApplicationContext applicationContext;
#Bean
public CustomKeyValueAdapter getKeyValueAdapter() {
return new CustomKeyValueAdapter();
}
#Bean("keyValueTemplate")
public KeyValueTemplate getKeyValueTemplate() {
return new KeyValueTemplate(getKeyValueAdapter());
}
}

how to load property file in to spring boot project with annotations?

I have written queries in property file. I want to read the property file in to one class with annotations in spring boot. How can i read it? And is there any better approach for writing queries in spring boot project?
If you add your properties in application.properties file, you can read them inside the spring boot classes like:
#Service
public class TwitterService {
private final String consumerKey;
private final String consumerKeySecret;
#Autowired
public TwitterService(#Value("${spring.social.twitter.appId}") String consumerKey, #Value("${spring.social.twitter.appSecret}") String consumerKeySecret) {
this.consumerKey = consumerKey;
this.consumerKeySecret = consumerKeySecret;
} ...
You can annotate fields in your components by #Value("${property.name}")
Else, you can use Properties Object in java.util package.
For example, i have a mode property, which values are dev or prod, i can use it in my beans as follow :
#Value("${mode:dev}")
private String mode;
The other approach is by using :
Properties pro = new Properties();
pro.load(this.getClass().getClassLoader().getResourceAsStream());
You can use #PropertySource to read the properties from a file and then pass them to a bean. If you have a file called "queries.properties" that has a property like:
query1: select 1 from foo
Then your config might look like:
#PropertySource("classpath:queries.properties")
#Configuration
public class MyConfig {
#Bean
public DbBean dbBean(#Value("${queries.query1}") String query) {
return new DbBean(query);
}
}

Using Scala classes as DTOs in Spring MVC

In my project I'm using Spring + Scala.
Some of my Spring MVC controllers uses Spring feature for binding incoming HTTP parameters to DTO object. Like this:
#RequestMapping(value = Array("/", ""), method = Array(RequestMethod.POST))
def saveProduct(dto: MyDto): Iterable[MyDto] = {...}
And MyDto is simple scala class:
class MyDto extends Serializable {
#BeanProperty var id : Long = _
#BeanProperty var name: String = _
}
My problem is that I'm getting exceptions when trying to use Scala Option class for fields in MyDto:
class MyDto extends Serializable {
#BeanProperty var id : Option[Long] = None
#BeanProperty var name: Option[String] = None
}
Exception message is:
Failed to convert property value of type 'java.lang.String' to required type 'scala.Option' for property 'name';
What I can do to use Scala Options as type if fields in MyDto?
I am not a Scala expert, but here is one way:
Create a converter, along these lines:
import org.springframework.core.convert.converter.Converter
class TypeToOptionOfTypeConverter[T] extends Converter[T, Option[T]] {
override def convert(source: T): Option[T] = {
Some(source)
}
}
Register this converter with Spring MVC:
class WebConfig extends WebMvcConfigurerAdapter {
override def addFormatters(registry: FormatterRegistry): Unit = {
registry.addConverter(classOf[String], classOf[Option[String]], new TypeToOptionOfTypeConverter[String])
registry.addConverter(classOf[Long], classOf[Option[Long]], new TypeToOptionOfTypeConverter[Long])
}
}
That should be it, now your DTO should get cleanly mapped.
Spring has support for converting types using converters with its data binding. You will need to implement the converter so that Spring knows how to convert, for example, String to Option[String].
See:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert

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