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Spring create generic service multiple times using generic in constructor

I have a service that uses some object as a generic
#Component
#RequiredArgsConstructor
public class SomeGenericService<T extends Base> {
private final T base;
public void someWork(String info) {
base.someAction(info);
}
}
I also have 3 Base implementations marked with #Component(Base1, Base2, Base3)
I want spring itself to create a service with the generic it needs, for the following example
#Component
#RequiredArgsConstructor
public class Runner implements CommandLineRunner {
private final SomeGenericService<Base1> s1;
private final SomeGenericService<Base2> s2;
private final SomeGenericService<Base3> s3;
#Override
public void run(String... args) throws Exception {
String someString = "text";
s1.someWork(someString);
s2.someWork(someString);
s3.someWork(someString);
}
}
But after the launch, the spring does not understand what I want from it.
Parameter 0 of constructor in SomeGenericService required a single bean, but 3 were found:
- base1: defined in file [Base1.class]
- base2: defined in file [Base2.class]
- base3: defined in file [Base3.class]
Is it possible to set this to automatic, without manually configuring it via the #Bean annotation for each service?

You need to define how those beans should be injected. It's a good practice to have some #Configurations for this purpose. Something like:
#Configuration
#Import({
Base1.class,
Base2.class,
Base3.class
})
public class SomeConfig {
#Bean
SomeGenericService<Base1> someGenericService1() {
return new SomeGenericService(new Base1());
}
#Bean
SomeGenericService<Base2> someGenericService2() {
return new SomeGenericService(new Base2());
}
#Bean
SomeGenericService<Base3> someGenericService3() {
return new SomeGenericService(new Base3());
}
}

Reading YAML properties file in spring boot via PropertySourceFactory using YamlMapFactoryBean

I'm trying to read a YAML configuration file through the spring boot #PropertySource mechanism, using a factory that utilizes the provided YamlMapFactoryBean parser.
The factory's implementation is as follows:
public class YamlPropertySourceFactory implements PropertySourceFactory {
#Override
public PropertySource<?> createPropertySource(String name, EncodedResource encodedResource) {
YamlMapFactoryBean factory = new YamlMapFactoryBean();
factory.setResources(encodedResource.getResource());
Map<String, Object> map = factory.getObject();
return new MapPropertySource(encodedResource.getResource().getDescription(), map);
}
}
The YAML configuration file (foo.yml) is:
yaml:
name: foo
aliases:
- abc
- xyz
The corresponding entity is:
#Configuration
#ConfigurationProperties(prefix = "yaml")
#PropertySource(value = "classpath:foo.yml", factory = YamlPropertySourceFactory.class)
public class YamlFooProperties {
private String name;
private List<String> aliases;
// Getters and Setters...
}
And finally, my test class is:
#RunWith(SpringRunner.class)
#SpringBootTest
public class YamlFooPropertiesTest {
#Autowired
private YamlFooProperties yamlFooProperties;
#Test
public void whenFactoryProvidedThenYamlPropertiesInjected() {
assertThat(yamlFooProperties.getName()).isEqualTo("foo");
assertThat(yamlFooProperties.getAliases()).containsExactly("abc", "xyz");
}
}
When debugging the factory, I see that the YAML file is parsed correctly and added to spring boot's propertySourceNames structure. However, when accessing it from the test in an Autowired fashion, all fields are null and the test therefore fails.

Spring-Boot multi module project load property-file

I have a Spring-Boot-Application as a multimodule-Project in maven. The structure is as follows:
Parent-Project
|--MainApplication
|--Module1
|--ModuleN
In the MainApplication project there is the main() method class annotated with #SpringBootApplication and so on. This project has, as always, an application.properties file which is loaded automatically. So I can access the values with the #Value annotation
#Value("${myapp.api-key}")
private String apiKey;
Within my Module1 I want to use a properties file as well (called module1.properties), where the modules configuration is stored. This File will only be accessed and used in the module. But I cannot get it loaded. I tried it with #Configuration and #PropertySource but no luck.
#Configuration
#PropertySource(value = "classpath:module1.properties")
public class ConfigClass {
How can I load a properties file with Spring-Boot and access the values easily? Could not find a valid solution.
My Configuration
#Configuration
#PropertySource(value = "classpath:tmdb.properties")
public class TMDbConfig {
#Value("${moviedb.tmdb.api-key}")
private String apiKey;
public String getApiKey() {
return apiKey;
}
#Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
}
Calling the Config
#Component
public class TMDbWarper {
#Autowired
private TMDbConfig tmdbConfig;
private TmdbApi tmdbApi;
public TMDbWarper(){
tmdbApi = new TmdbApi(tmdbConfig.getApiKey());
}
I'm getting an NullPointerException in the constructor when I autowire the warper.

For field injection:
Fields are injected right after construction of a bean, before any config methods are invoked. Such a config field does not have to be public. Refer Autowired annotation for complete usage. Use constructor injection in this case like below:
#Component
public class TMDbWarper {
private TMDbConfig tmdbConfig;
private TmdbApi tmdbApi;
#Autowired
public TMDbWarper(final TMDbConfig tmdbConfig){
this.tmdbConfig = tmdbConfig;
tmdbApi = new TmdbApi(tmdbConfig.getApiKey());
}
(or)
Use #PostConstruct to initialise like below:
#Component
public class TMDbWarper {
#Autowired
private TMDbConfig tmdbConfig;
private TmdbApi tmdbApi;
#PostConstruct
public void init() {
// any initialisation method
tmdbConfig.getConfig();
}

Autowiring is performed just after the creation of the object(after calling the constructor via reflection). So NullPointerException is expected in your constructor as tmdbConfig field would be null during invocation of constructor
You may fix this by using the #PostConstruct callback method as shown below:
#Component
public class TMDbWarper {
#Autowired
private TMDbConfig tmdbConfig;
private TmdbApi tmdbApi;
public TMDbWarper() {
}
#PostConstruct
public void init() {
tmdbApi = new TmdbApi(tmdbConfig.getApiKey());
}
public TmdbApi getTmdbApi() {
return this.tmdbApi;
}
}
Rest of your configuration seems correct to me.
Hope this helps.

Here is a Spring Boot multi-module example where you can get properties in different module.
Let's say I have main application module, dataparse-module, datasave-module.
StartApp.java in application module:
#SpringBootApplication
public class StartApp {
public static void main(String[] args) {
SpringApplication.run(StartApp.class, args);
}
}
Configuration in dataparse-module. ParseConfig.java:
#Configuration
public class ParseConfig {
#Bean
public XmlParseService xmlParseService() {
return new XmlParseService();
}
}
XmlParseService.java:
#Service
public class XmlParseService {...}
Configuration in datasave-module. SaveConfig.java:
#Configuration
#EnableConfigurationProperties(ServiceProperties.class)
#Import(ParseConfig.class)//get beans from dataparse-module - in this case XmlParseService
public class SaveConfig {
#Bean
public SaveXmlService saveXmlService() {
return new SaveXmlService();
}
}
ServiceProperties.java:
#ConfigurationProperties("datasave")
public class ServiceProperties {
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
}
application.properties in datasave-module in resource/config folder:
datasave.message=Multi-module Maven project!
threads.xml.number=5
file.location.on.disk=D:\temp\registry
Then in datasave-module you can use all your properties either through #Value.
SaveXmlService.java:
#Service
public class SaveXmlService {
#Autowired
XmlParseService xmlParseService;
#Value("${file.location.on.disk: none}")
private String fileLocation;
#Value("${threads.xml.number: 3}")
private int numberOfXmlThreads;
...
}
Or through ServiceProperties:
Service.java:
#Component
public class Service {
#Autowired
ServiceProperties serviceProperties;
public String message() {
return serviceProperties.getMessage();
}
}

I had this situation before, I noticed that the properties file was not copied to the jar.
I made the following to get it working:
In the resources folder, I have created a unique package, then stored my application.properties file inside it. e.g: com/company/project
In the configuration file e.g: TMDBConfig.java I have referenced the full path of my .properties file:
#Configuration
#PropertySource("classpath:/com/company/project/application.properties")
public class AwsConfig
Build and run, it will work like magic.

You could autowire and use the Enviornment bean to read the property
#Configuration
#PropertySource(value = "classpath:tmdb.properties")
public class TMDbConfig {
#Autowired
private Environment env;
public String getApiKey() {
return env.getRequiredProperty("moviedb.tmdb.api-key");
}
}
This should guarantee that property is read from the context when you invoke the getApiKey() method regardless of when the #Value expression is resolved by PropertySourcesPlaceholderConfigurer.

Spring boot #ConfigurationProperties not loaded

As the title says, I'm trying to use Typesafe Configuration Properties to load a list of DataSourceConfig objects. I have lombok for setter/getters
The main application class annotations
#Slf4j
#SpringBootApplication
#EnableConfigurationProperties
public class Application {
The configuration pojo
#Data
public class DataSourceConfig {
private String key;
private String dbname;
private String dbpath;
}
The yml file
tenantdb:
dataSourceConfig:
-
key: default
dbpath: file:eventstore/jdbc/database
dbname: defaultdb
-
key: other
dbpath: file:eventstore/jdbc/other
dbname: dslfjsdf
Finally, the Spring Configuration class with the #ConfigurationProperties annotation.
#Configuration
#Profile("hsqldb")
#ImportResource(value = { "persistence-config.xml" })
#Slf4j
#ConfigurationProperties(prefix="tenantdb", locations={"datasources.yml"})
public class HsqlConfiguration {
private List<DataSourceConfig> dataSourceConfig = new ArrayList<>();
#Bean
public List<DataSourceConfig> getDataSourceConfig() {
return dataSourceConfig;
}
With the config above, I get:
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hsqlConfiguration': Could not bind properties to [unknown] (target=tenantdb, ignoreInvalidFields=false, ignoreUnknownFields=true, ignoreNestedProperties=false); nested exception is java.lang.NullPointerException
at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:303)
at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:250)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:408)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initia
I've tried various combinations. If I change the annotation to #ConfigurationProperties(prefix="tenantdb.dataSourceConfig"), I don't get the error but List<DataSourceConfig> is empty.
HELP!!

You should use configuration properties as simple POJO with only getters and setters and have separate HsqlConfiguration which has this properties injected.
Something like this:
#Component
#ConfigurationProperties(prefix="tenantdb", locations={"datasources.yml"})
public class TenantDbProperties {
//DataSourceConfig is POJO with key, dbpath and dbname
private List<DataSourceConfig> dataSourceConfigs;
public List<DataSourceConfig> getDataSourceConfigs(){
return dataSourceConfigs;
}
public void setDataSourceConfigs(List<DataSourceConfig> dataSourceConfigs){
this.dataSourceConfigs = dataSourceConfigs;
}
}
And in separate class have this properties injected as:
#Configuration
#Profile("hsqldb")
#ImportResource(value = { "persistence-config.xml" })
#Slf4j
public class HsqlConfiguration {
#Autowired
private TenantDbProperties tenantDbProperties;
//code goes here where you can use tenantDbProperties.getDataSourceConfigs()
}

In spring boot how to load a yml section as java.util.Properties

In my spring boot application, I have following configuration:
server:
host: a.com
port: 5922
enable-log: true
I want to read the above as a java.util.Properties. I tried putting following class:
#ConfigurationProperties(prefix = "server")
public class ServerConfig {
private Properties serverProps;
// ... Getter/setter
}
The boot config files look like:
#Configuration
#ComponentScan("com.demo")
#EnableAspectJAutoProxy(proxyTargetClass = true)
#EnableConfigurationProperties({ServerConfig.class})
#Profile({"dev"})
public class TestAppConfiguration {
}
#EnableAutoConfiguration
#SpringBootApplication
public class TestAppInitializer {
public static void main(final String[] args) {
SpringApplication.run(TestAppInitializer.class, args);
}
}
Unit test class:
#SpringApplicationConfiguration(classes = {TestAppInitializer.class})
#ActiveProfiles("dev")
public class ServerConfigTest extends AbstractTestNGSpringContextTests {
#Autowired
private ServerConfig serverConfig;
#Test
public void printDetails() {
logger.debug("ServerConfig.properties --> {}", serverConfig.getProperties());
}
}
The output is
ServerConfig.properties --> null.
I am not sure why is this happening. The only idea that comes to my mind is, the configuration parameters underneath server are basically flat strings. Is there any way I can read those as Properties?

#Bean({"kaptchaProperties"})
#ConfigurationProperties(prefix = "custom.kaptcha")
public Properties getProperties() {
return new Properties();
}

AFAIK, you can't load them into java.util.Properties with annotation #ConfigurationProperties.
You need to create this:
#Component
#ConfigurationProperties(prefix = "server")
public class ServerConfig {
private String host;
private String port;
private String enableLog;
// ... Getter/setter
}