IOC containers: de-duplicating the configuration code - java

I am using spring framework for 2 different applications. Let's say both of the applications talk to one single MongoDB database. Following is how I configure MongoDB in both the applications:
#Configuration
#PropertySource("file:/etc/x/y/mongodb.properties")
public class MongoConfiguration {
#Autowired
private Environment env;
#Bean
public UserCredentials mongoCredentials() {
String mongoUserName = env.getProperty("mongodb.username");
String mongoPassword = env.getProperty("mongodb.password");
UserCredentials credentials = new UserCredentials(mongoUserName, mongoPassword);
return credentials;
}
#Bean
public MongoClient mongoClient() throws Exception {
String mongoUrl = env.getProperty("mongodb.url");
String mongoPort = env.getProperty("mongodb.port");
MongoClient mongo = new MongoClient(mongoUrl, Integer.valueOf(mongoPort));
return mongo;
}
#Bean(name="mongoTemplate")
public MongoTemplate mongoTemplate() throws Exception {
String mongoDatabaseName = env.getProperty("mongodb.databasename");
MongoTemplate mongoTemplate = new MongoTemplate(mongoClient(), mongoDatabaseName, mongoCredentials());
return mongoTemplate;
}
Now, this piece of code is duplicated in two different application configurations. How do I avoid doing this configuration at two different places?

Treat it the same as a util class that you don't want to duplicate: move you config file to a separate project and make both your applications include that projects.
If you need to add additional project-specific configuration, Spring provides the #Import annotation that allows you to import configuration from separate classes, so you can create two project specific configuration classes that both import the generic configuration from the shared lib and supply their own individual beans and property sources, e.g.:
#Configuration
#PropertySource("classpath:/com/appspecific/app.properties")
#Import(com.genericlib.BaseConfig.class)
public class AppConfig {
#Inject BaseConfig baseConfig;
#Bean
public MyBean myBean() {
// reference the base config context
return new MyBean(baseConfig.getSomething());
}
}

Use Spring Boot, and optionally include the #PropertySource to add to the environment. It will collect all the MongoDB information and configure a client and template for you.

Related

How to create datasource bean at runtime without crashing app in Spring?

I am connecting to multiple datasources but sometimes some datasources may be offline and at that time I am geting errors on app and application is failing at startup.
I want to skip datasource configuration at startup... I have tried several ways by adding
spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
to the application.properties and also I have tried adding
#SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
to the main class but still it tries to configure the datasource.
I also tried to use #Lazy annotation on all methods and on constructor as below but still getting error while creating fooEntityManagerFactory
#Lazy
#Configuration
#EnableJpaRepositories(basePackages = "com.heyo.tayo.repository.foo", entityManagerFactoryRef = "fooEntityManagerFactory", transactionManagerRef = "fooTransactionManager")
public class PersistencefooConfiguration {
#Autowired
private DbContextHolder dbContextHolder;
#Lazy
#Bean
#ConfigurationProperties("tay.datasource.foo")
public DataSourceProperties fooDataSourceProperties() {
return new DataSourceProperties();
}
#Lazy
#Bean
#ConfigurationProperties("tay.datasource.foo.configuration")
public DataSource fooDataSource() {
DataSource dataSource = fooDataSourceProperties().initializeDataSourceBuilder()
.type(BasicDataSource.class).build();
dbContextHolder.addNewAvailableDbType(DbTypeEnum.foo);
return dataSource;
}
#Lazy
#Bean(name = "fooEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean fooEntityManagerFactory(
EntityManagerFactoryBuilder builder) {
//THE CODE IS FAILING AT BELOW RETURN CASE
return builder
.dataSource(fooDataSource())
.packages("com.heyo.tayo.model.foo")
.build();
}
#Lazy
#Bean
public PlatformTransactionManager fooTransactionManager(
final #Qualifier("fooEntityManagerFactory") LocalContainerEntityManagerFactoryBean fooEntityManagerFactory) {
return new JpaTransactionManager(fooEntityManagerFactory.getObject());
}
}
I have multiple classes like above for different configs for different datasources and I am adding them to available dbs static list at datasource Bean.
Here is my dbadapter factory class.
Here is my dbAdaptor factory that creates corresponding db adaptor
#Service
public class DbAdapterFactory {
#Autowired
private BeanFactory beanFactory;
#Autowired
private DbContextHolder dbContextHolder;
public DBAdapter dbAdapter(){
DbTypeEnum currentDb = dbContextHolder.getCurrentDb();
DBAdapter dbAdapter = null;
if(currentDb == DbTypeEnum.FOODB) {
dbAdapter = beanFactory.getBean(foodbadaptor.class);
} else {
dbAdapter = beanFactory.getBean(koodbadaptor.class);
}
return dbAdapter;
}
Here is db context holder that makes operation like setting default db or getting current db etc.:
#Component
public class DbContextHolder {
private DbTypeEnum dbType = DbTypeEnum.FOODB;
private Set<DbTypeEnum> availableDbTypes = new HashSet<>();
public void setCurrentDb(DbTypeEnum dbType) {
this.dbType = dbType;
}
public DbTypeEnum getCurrentDb() {
return this.dbType;
}
public List<DbTypeEnum> getAvailableDbTypes() {
return new ArrayList<>(availableDbTypes);
}
public void addNewAvailableDbType(DbTypeEnum dbTypeEnum) {
availableDbTypes.add(dbTypeEnum);
}
}
I made all #Lazy or tried #SpringBootApplication(exclude={DataSourceAutoConfiguration.class}) but still something is calling to create bean and getting error and app is closing. I want to use that config and datasource in a try-catch block and don't stop application at runtime. How can I achieve this or what am I missing on that configs or annotations ?
I believe that you can simply add in your application properties
spring.sql.init.continue-on-error=true
According to the Spring Boot 2.5.5 user guide:
https://docs.spring.io/spring-boot/docs/2.5.5/reference/htmlsingle/#howto-initialize-a-database-using-spring-jdbc
Spring Boot enables the fail-fast feature of its script-based database initializer. If the scripts cause exceptions, the application fails to start. You can tune that behavior by setting spring.sql.init.continue-on-error.
Depending on your spring boot version the property will be named either
spring.sql.init.continue-on-error
or before Spring Boot 2.5
spring.datasource.continue-on-error
It is so dumb but I solved the problem by adding following to application.properties.
spring.jpa.database=sql_server
I have no idea why I need to specify that explicitly in properties file but the problem is solved. I will search for it

Accessing application.conf on play module configuration

I'm trying to configure a database client instance using Guice to create an AbstractModule, but i can't access application.conf using dependency injection, since the injector is not created yet.
Here is my code
#Singleton
public class DatastoreModule extends AbstractModule {
#Inject
private Config config;
#Override
public void configure() {
MongoClient mongo = new MongoClient(
config.getString("mongodb.host"),
config.getInt("mongodb.port")
);
Morphia morphia = new Morphia();
Datastore datastore = morphia.createDatastore(
mongo,
config.getString("mongodb.databaseName")
);
bind(Datastore.class).toInstance(datastore);
}
}
How can i access the configuration without using the deprecated Play.configuration API?
You can pass it in the constructor (in Scala). Here is the example from my project
class Guard(environment: Environment, configuration: Configuration) extends AbstractModule{
In Java it is the same:
public class DatastoreModule extends AbstractModule {
private final Environment environment;
private final Config config;
public DatastoreModule(Environment environment, Config config) {
this.environment = environment;
this.config = config;
}
...
}
More details: https://www.playframework.com/documentation/2.6.x/JavaDependencyInjection#Configurable-bindings
Just do not overuse it:
In most cases, if you need to access Config when you create a component, you should inject the Config object into the component itself or into the component’s Provider. Then you can read the Config when you create the component. You usually don’t need to read Config when you create the bindings for the component.
I very very rarely use it. It is always almost better to inject the configuration into component itself.

How to access spring boot properties from freemarker template

My problematic is really simple :
In my spring-boot web application, I have some env-related properties that the front/client-side needs to know about (let's say, a CORS remote url to call that is env dependant).
I have correctly defined my application-{ENV}.properties files and all the per-env-props mecanism is working fine.
The question I can't seem to find answer to is : how do you allow your freemarker context to know about your properties file to be able to inject them (specifically in a spring-boot app). This is probably very easy but I cant find any example...
Thanks,
Gonna answer myself :
Easiest way in spring-boot 1.3 is to overrides the FreeMarkerConfiguration class :
/**
* Overrides the default spring-boot configuration to allow adding shared variables to the freemarker context
*/
#Configuration
public class FreemarkerConfiguration extends FreeMarkerAutoConfiguration.FreeMarkerWebConfiguration {
#Value("${myProp}")
private String myProp;
#Override
public FreeMarkerConfigurer freeMarkerConfigurer() {
FreeMarkerConfigurer configurer = super.freeMarkerConfigurer();
Map<String, Object> sharedVariables = new HashMap<>();
sharedVariables.put("myProp", myProp);
configurer.setFreemarkerVariables(sharedVariables);
return configurer;
}
}
One option in spring boot 2:
#Configuration
public class CustomFreeMarkerConfig implements BeanPostProcessor {
#Value("${myProp}")
private String myProp;
#Override
public Object postProcessBeforeInitialization(Object bean, String beanName)
throws BeansException {
if (bean instanceof FreeMarkerConfigurer) {
FreeMarkerConfigurer configurer = (FreeMarkerConfigurer) bean;
Map<String, Object> sharedVariables = new HashMap<>();
sharedVariables.put("myProp", myProp);
configurer.setFreemarkerVariables(sharedVariables);
}
return bean;
}
}
Spring Boot 2.x changed class structure so it's no longer possible to subclass and keep the auto configuration like was possible with Spring Boot 1.x.
import freemarker.template.Configuration;
#Component
public class FreemarkerConfiguration {
#Autowired
private Configuration freemarkerConfig;
#Value("${myProp}")
private String myProp;
Map<String, Object> model = new HashMap();
model.put("myProperty", myProp);
// set loading location to src/main/resources
freemarkerConfig.setClassForTemplateLoading(this.getClass(), "/");
Template template = freemarkerConfig.getTemplate("template.ftl");
String templateText = FreeMarkerTemplateUtils.
processTemplateIntoString(template, model);
}
step 2,
get property in freemarker template code.
<div>${myProperty}</td>

Using different java based spring context configurations with cucumber

I am trying to get Cucumber working with Spring. In our code, we are already using java based Spring configuration. I am having trouble getting it to work in the following scenario. Can someone please help?
Today , in our integration test classes we use #ContextConfiguration for each class and provide the config class that is declared with in that integration test class for loading the beans. Config class is annotated with #Configuration. Same bean could be instantiated differently in 2 different classes Config classes used in 2 different integration test classes.
So when I use Cucumber, since the Contextconfiguration differs on different classes, it looks for 'Cucumber.xml' . In the xml file, I am using component-scan to scan the cucumber step definition classes by giving the package name that these classes use (both classes have same package name) . Since all beans gets loaded in same context, Cucumber is failing to load the beans when it finds the same bean defined in these different config classes .
How do I get over this problem of creating same bean but in different ways and use them in different classes?
Please note that I am not looking for a solution that creates lot of churn from our existing coding practices, so having per-test-xml file is not an option for me.
Here is how our code looks:
Class NameAndAddressProviderIntegrationTestSteps :-
#ContextConfiguration(locations="classpath:cucumber.xml")
public class NameAndAddressProviderIntegrationTestSteps {
#Configuration
#Import({
xyz.class,
abc.class,
NameAndAddressProvider.class
})
#ImportResource({
"file:configuration/spring-configuration/abc.xml",
"file:configuration/spring-configuration/xyz.xml"
})
public static class Config {
#Bean
AccountHolderDataMap dataMap() {
AccountHolderDataMap data = new AccountHolderDataMap();
data.put(ID,
new AccountHolderData(customerID));
data.get(customerID).setCustomerplaceID(testCustomerplaceID);
return data;
}
}
#Inject
private NameAndAddressProvider provider;
#When("^I call nameandAddress provider with a 'customerId'$")
public void i_call_nameandAddress_provider_with_a_customerId() throws DependencyException {
System.out.println("Entering when method");
names = provider.getNames(customerID);
System.out.println(provider.toString());
}
......
}
Class AddressProviderIntegrationTestSteps:-
#ContextConfiguration(locations="classpath:cucumber.xml")
public class AddressProviderIntegrationTestSteps {
#Configuration
#Import({
abc.class,
xyz.class,
AddressesProvider.class
})
#ImportResource({
"file:configuration/spring-configuration/test-environment.xml",
"file:configuration/spring-configuration/test-logging-config.xml"
})
public static class Config {
#Bean
#DependsOn("Environment")
AccountHolderDataMap data() {
AccountHolderDataMap data = new AccountHolderDataMap();
data.put(testCustomerID,
new AccountHolderData(testCustomerID, testCustomerplaceID,businessType));
return data;
}
}
private static final String testCustomerID = "1234";
private static final String testMarketplaceID = "abc";
#Inject
private AddressesProvider provider;
#When("^I call AddressesProvider provider with a 'CustomerID'$")
public void i_call_AddressesProvider_provider_with_a_CustomerID() throws Throwable {
List<Address> addresses = provider.getAddresses(testCustomerID);
Log.info(addresses.get(0).toString());
assertTrue(addresses.size()==1);
}
}
And here is the nested exception I am getting:-
"nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [....AccountHolderDataMap] is defined: expected single matching bean but found 2: dataMap,data"
Appreciate your help!
I've managed multiple sources for bean-definitions. You can use this at a starting point (or others in the internet as your question is quite old)
I am using spring4, see my other cucumer post for the pom
At the stepdefs use a config.class
#ContextConfiguration(classes = { CucumberConfiguration.class })
public class StepdefsTest123 {
#Autowired bean; // from cucumberBeanContext.xml
#When("^A$")
public void a() throws Throwable {
System.out.println(bean.getFoo());
}
}
in the config-class add aditional beandefinitions
#Configuration
#ComponentScan(basePackages = "package.here.cucumber")
#ImportResource("classpath:cucumberBeanContext.xml")
public class CucumberConfiguration {
// nothing to do here
}

How to execute SQL insert queries to populate database during application start/load?

I want to load some data into the mysql database during loading of the application. I am using Hibernate for managing database for the application. I can do it in groovy by using Bootstrap but I want to achieve it in Java. I would like to mention that it is Spring MVC based web application.
While searching on the internet, I found that but using hibernate property named as import_file, I can achieve it but I am looking for an alternate route.
You could also take advantage of Spring's DataSourceInitializer . The following is an example of Java Config for it.
#Bean
public DataSourceInitializer dataSourceInitializer() {
ResourceDatabasePopulator resourceDatabasePopulator = new ResourceDatabasePopulator();
resourceDatabasePopulator.addScript(new ClassPathResource("/data.sql"));
DataSourceInitializer dataSourceInitializer = new DataSourceInitializer();
dataSourceInitializer.setDataSource(dataSource());
dataSourceInitializer.setDatabasePopulator(resourceDatabasePopulator);
return dataSourceInitializer;
}
Spring already provides a way of initializing databases with content, using a DatabasePopulator.
Here's one quick example that I found, for a Spring Batch sample application. The class to look at in that code is ResourceDatabasePopulator.
Another example is in Spring Social project samples.
I would go for registering an instance of ApplicationListener in the Spring context configuration, that listens for the ContextRefreshedEvent, which is signalled when the application context has finished initializing or being refreshed. After this moment you could setup your database population.
Below you will find the ApplicationListener implementation (which depends on the DAO responsible for performing the database operations) and the Spring configuration (both Java and XML)that you need to achieve this. You need to choose the configuration specific to your app:
Java-based configuration
#Configuration
public class JavaConfig {
#Bean
public ApplicationListener<ContextRefreshedEvent> contextInitFinishListener() {
return new ContextInitFinishListener(personRepository());
}
#Bean
public PersonRepository personRepository() {
return new PersonRepository();
}
}
XML
<bean class="com.package.ContextInitFinishListener">
<constructor-arg>
<bean class="com.package.PersonRepository"/>
</constructor-arg>
</bean>
This is the code for the ContextInitFinishListener class:
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
public class ContextInitFinishListener implements ApplicationListener<ContextRefreshedEvent> {
private PersonRepository personRepository;
public ContextInitFinishListener(PersonRepository personRepository) {
this.personRepository = personRepository;
}
#Override
public void onApplicationEvent(ContextRefreshedEvent event) {
//populate database with required values, using PersonRepository
}
}
NOTE: PersonRepository is just a generic DAO for the purpose of the example, it's meant to represent the DAO that YOU use in your app
I used as below in my spring boot console application test.
ResourceDatabasePopulator rdp = new ResourceDatabasePopulator();
rdp.addScript(new ClassPathResource("sql/create-tables.sql"));
rdp.execute(dataSource);
there are different ways to get datasource depending on type of application or data layered framework.
if u r using spring boot atoconfigured h2 datasource u can use.
#Autowired
Datasource datasource;
to get the data source throgh external configuration class is below
#Value("${spring.datasource.driver-class-name}")
private String driverClass;
#Value("${spring.datasource.url}")
private String dbUrl;
#Value("${spring.datasource.username}")
private String dbUserName;
#Value("${spring.datasource.password}")
private String dbPassword;
#Bean
public DataSource dataSource(){
SingleConnectionDataSource dataSource = new
SingleConnectionDataSource();
dataSource.setDriverClassName(driverClass);
dataSource.setUrl(dbUrl);
dataSource.setUsername(dbUserName);
dataSource.setPassword(dbPassword);
dataSource.setSuppressClose(true);
dataSource.setAutoCommit(true);
return dataSource;
}
this worked for me, keep al queries that u need to execute in create-tables.sql

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