Develop Reference

How to inject pojo class in spring?

I have a pojo class which i need to inject in component. how to inject pojo object in spring?
For example
RestClass is under Module(like one microservice). Pojo Value should be injected here only. service class and pojo is different module.
#Controller
public class RestClass {
#Autowired
private ServiceClass serviceClass;
// How to apply MyConfig pojo object into ServiceClass
//like MyConfig.Builder().limit(100).build();
#PostMapping("/business")
private void callDoBusiness(){
serviceClass.doBusiness();
}
}
//// ServiceClass and Pojo class is under one module. Pojo object should not construct here. should be passed from another module
#Service
public class ServiceClass {
#Autowired
private MyConfig myConfig;
public void doBusiness(){
System.out.println(myConfig.getLimit())
}
}
#Builder
#Getter
public class MyConfig {
private int limit;
.
.
}

#Bean annotation is used in your case. For example:
Create some configuration file with #Configuration annotation. It doesn't matter where you create your Config configuration class or how you name it. You can even have multiple #Configuration classes across your project.
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
#Configuration
class Config {
// configure your MyConfig class here as a bean
#Bean
public MyConfig myConfig() {
return MyConfig.Builder().limit(100).build();
}
}
Now you can autowire it wherever you use it as in you example.

You can use #Configuration and #Bean. Something like this
AppConfig.java
#Configuration
public class AppConfig {
#Bean
public PojoClass getBean(){ return new PojoClass();}
}

You can use #Bean
#Configuration
public class Config {
#Bean
public MyConfig MyConfig() {
return new MyConfig();
}
}

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.

#Autowire Not Setting DAO

I have the following Spring Java configuration set up:
#Configuration
public class FooConfig {
#Autowired
private IReferenceDataDAO referenceDataDAO;
#Bean
public IReferenceDataService getReferenceDataService() {
return new ReferenceDataServiceImpl(referenceDataDAO);
}
}
I am trying to reference the ReferenceDataService bean in another configuration class using the #Autowire property:
#Configuration
public class BarConfig {
#Autowired
private IRuleService ruleService;
#Autowired
private IReferenceDataService referenceDataService;
}
Here is the config that defines the IReferenceDataDAO:
#Configuration
public class FooBarConfig {
#Bean
public IReferenceDataDAO getReferenceDataDAO() {
return new ReferenceDataDAOImpl(getStaticData(), getMapper());
}
}
Here is the ReferenceDataServiceImpl:
public class ReferenceDataServiceImpl implements IReferenceDataService {
private IReferenceDataDAO dao;
public ReferenceDataServiceImpl(IReferenceDataDAO dao) {
this.dao = dao;
}
The above configs are imported in a master config class:
#Configuration
#Import({
FoosAppConfig.class,
BarAppConfig.class,
FooBarAppConfig.class,
})
I am noticing that this configuration leads to the referenceDAO in the ReferenceDataServiceImpl being set to null. What am I doing wrong? Shouldn't that #Autowire annotation ensure that my bean is fully configured before setting it?

BarConfig needs to import FooConfig
#Import({ FooConfig.class })

Try this:
#Configuration
#Import({ FooConfig.class })
public class BarConfig {
#Autowired
private IRuleService ruleService;
#Autowired
private IReferenceDataService referenceDataService;
}
This allows BarConfig to get access to the IReferenceDataService bean.

spring-boot properties not #Autowired

I am trying to get a Spring-boot application going and I am not sure what I am doing wrong here. I have a application.properties file at src/main/resources & src/test/resources. I have an #Bean for my ConfigurationSettings so that I can use them throughout my application:
#Component
public class ConfigurationSettings {
private String product;
private String version;
private String copyright;
private String appName;
private String appDescription;
...
// getters and setters
}
Here is how I kick the application off:
#Configuration
#EnableJpaRepositories
#EnableAutoConfiguration
#EnableConfigurationProperties
#PropertySources(value = {#PropertySource("classpath:application.properties")})
#ComponentScan(basePackages = "com.product")
#EnableScheduling
public class OFAC {
public static void main(String[] args) {
ApplicationContext ctx = SpringApplication.run( OFAC.class, args );
}
And here is my configuration class:
#Configuration
#ComponentScan(basePackages = {"com.product"})
#PropertySources(value = {#PropertySource("classpath:application.properties")})
public class OFAConfiguration {
#Autowired
private Environment env;
#Bean
public ConfigurationSettings configurationSettings() {
ConfigurationSettings configurationSettings = new ConfigurationSettings();
configurationSettings.setAppDescription( env.getRequiredProperty("app.description" ) );
configurationSettings.setAppName( env.getRequiredProperty( "app.name" ) );
configurationSettings.setServerPort( env.getRequiredProperty( "server.port" ) );
return configurationSettings;
}
I am trying to use it in a controller:
#RestController
public class AboutController {
#Autowired
private ConfigurationSettings configurationSettings;
#RequestMapping(value = "/about", method = RequestMethod.GET)
public About index() {
String product = configurationSettings.getProduct();
String version = configurationSettings.getVersion();
String copyright = configurationSettings.getCopyright();
return new About( product, version, copyright );
}
}
However, when step thru this, all the values of ConfigurationSettings are null. I do have a test that successfully loads the values:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = {OFAConfiguration.class})
public class OFAConfigurationTest {
#Autowired
private Environment environment;
#Autowired
private ConfigurationSettings configurationSettings;
#Test
public void testConfigurationLoads() {
assertNotNull(environment);
Assert.assertNotNull(configurationSettings);
}
#Test
public void testConfigurationSettingValues() {
assertEquals("Product Name", configurationSettings.getProduct());
assertEquals("0.0.1", configurationSettings.getVersion());
assertEquals("2014 Product", configurationSettings.getCopyright());
}
Can anyone see why the ConfigurationSettings are not being populated in my Controller?

Your configuration leads to 2 instances of the ConfigurationSettings class and probably one instance overrides the other.
The 'ConfigurationSettings' has the #Component annotation as you are scanning for components (#ComponentScan) this will lead to an instance. You also have a #Bean annotated method which also leads to an instance. The latter is overridden with the first.
In short remove the #Component annotation as that isn't needed because you already have a factory method for this class.
public class ConfigurationSettings { ... }
You should also remove the #PropertySource annotations as Spring-Boot will already load the application.properties for you.
Finally you should not use the #ContextConfiguration annotation on your test class but the #SpringApplicationConfiguration and pass in your application class (not your configuration class!).
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes=OFAC.class)
public class OFAConfigurationTest {
#Autowired
private Environment environment;
#Autowired
private ConfigurationSettings configurationSettings;
#Test
public void testConfigurationLoads() {
assertNotNull(environment);
assertNotNull(configurationSettings);
}
#Test
public void testConfigurationSettingValues() {
assertEquals("Product Name", configurationSettings.getProduct());
assertEquals("0.0.1", configurationSettings.getVersion());
assertEquals("2014 Product", configurationSettings.getCopyright());
}
This will fix your runtime configuration problems and will let your test use the power of Spring Boot to configure your application.

XML-less configuration for spring

I have the following configuration bean for a non web app
#Configuration
public class MyBeans {
#Bean
#Scope(value="prototype")
MyObject myObject() {
return new MyObjectImpl();
}
}
On the other side I have my class
public class MyCommand implements Command {
#Autowired
private MyObject myObject;
[...]
}
How can I make myCommand be autowired with the configuration in MyBeans without using XML so I can inject mocks in my other test classes?
Thanks a lot in advance.

With XML-based configuration you'd use the ContextConfiguration annotation. However, the ContextConfiguration annotation doesn't appear to work with Java Config. That means that you have to fall back on configuring your application context in the test initialization.
Assuming JUnit4:
#RunWith(SpringJUnit4ClassRunner.class)
public class MyTest{
private ApplicationContext applicationContext;
#Before
public void init(){
this.applicationContext =
new AnnotationConfigApplicationContext(MyBeans.class);
//not necessary if MyBeans defines a bean for MyCommand
//necessary if you need MyCommand - must be annotated #Component
this.applicationContext.scan("package.where.mycommand.is.located");
this.applicationContext.refresh();
//get any beans you need for your tests here
//and set them to private fields
}
#Test
public void fooTest(){
assertTrue(true);
}
}